October 24th, 2020 Virtual Zoom Conference

2020 Midwest Drosophila Conference

ABSTRACT BOOK

2018 Midwest Drosophila Conference ABSTRACTS TALKS 1. Building a planar signaling system that directs actin protrusion and collective migration of epithelial cells Audrey M. Williams and Sally Horne-Badovinac Presenting author: Audrey M. Williams University of Chicago Cells migrating as a collective need to ensure that their leading and trailing edges align with their neighbors, a form of planar cell polarity. We study how a novel planar cell polarity system in the Drosophila egg chamber epithelium coordinates one such collective migration. The follicle cells that make up the egg chamber epithelium undergo a highly coordinated collective migration along an underlying basement membrane extracellular matrix. The tissue lacks leader cells, and tissue-level polarity emerges from cell-cell interactions across the field. We show that Fat2, an atypical cadherin that localizes to the trailing edge, promotes lamellipodial protrusion by recruiting the Wave complex to clusters at the leading edge of the cell behind. Fat2 also recruits Lar and Sema-5c, two transmembrane signaling proteins, to these leading edge clusters to form a planar-polarized intercellular signaling complex. Acute disruption of Fat2 signaling with the calcium chelator EGTA causes dissociation of Lar, Sema-5c, and the Wave complex, and abruptly halts migration. Upon restoration of calcium, the Fat2 signaling complexes reassemble, the tissue selects a new planar-polarization vector, and migration resumes. With this manipulation, we can use live imaging to watch the entirety of tissue polarization and signaling complex assembly. Key next questions include 1) How does the Fat2 signaling complex organize asymmetrically across cell-cell junctions and 2) How does polarity information propagate across the cell field? 2. Simulation and in vivo experimentation predict AdamTS-A location of function during caudal visceral mesoderm (CVM) migration in Drosophila William C. Hamilton, Magdalena A. Stolarska, and Afshan Ismat Presenting author: Afshan Ismat University of St. Thomas Cells that migrate as collectives are either attached to each other or not during the process of migration. In this study, we examined the migration of caudal visceral mesoderm (CVM) cells during Drosophila embryogenesis, and how one extracellular protease, AdamTS-A, facilitates this migration. CVM cells migrate as a loose collective along the trunk visceral mesoderm (TVM) substrate and are surrounded by ECM. Using both in vivo experimentation and mathematical simulations, we have demonstrated that AdamTS-A cleaves connections between individual CVM cells and the ECM on all sides not attached to the TVM. Absence of AdamTS-A resulted in mis-migration of CVM cells. A comparison of mathematical simulation to experimental results demonstrated that the location of action of AdamTS-A in CVM cells is on the side opposite the CVM-TVM interface, predominantly at the CVM-ECM interface where CVM cells are not in contact with one another. In order to confirm these results, we observed CVM migration from the dorsal view (top down view) which showed CVM cells migrating along the outside of the TVM substrate in the absence of AdamTS-A. Moreover, over-expression of AdamTS-A resulted in similar, but milder, mis-migration of CVM. These results are in contrast to the salivary gland that migrates as a collective where all cells are attached to each other. In the salivary gland AdamTS-A is proposed to cleave connections only at the trailing edge of migrating cells. We conclude that, depending on the type of collective cell migration, AdamTS-A functions differently.

3. The Forkhead/Fox domain transcription factor Jumeau mediates specific cardiac progenitor cell divisions by regulating the expression of the kinesin Nebbish Andrew J. Kump, Manoj Panta, Kristopher R. Schwab, Mark H. Inlow, and Shaad M. Ahmad Presenting author: Andrew J. Kump Indiana State University Forkhead (Fkh/Fox) domain transcription factors (TFs) mediate multiple cardiogenic processes in both mammals and Drosophila. We showed previously that the Drosophila Fox gene jumeau (jumu) controls three categories of cardiac progenitor cell division—asymmetric, symmetric, and cell division at an earlier stage—by regulating Polo kinase activity, and mediates the latter two categories in concert with the TF Myb. Those observations raised the question of whether other jumu-regulated genes also mediate all three categories of cardiac progenitor cell division or a subset thereof. By comparing microarray-based expression profiles of wild-type and jumu loss-of-function mesodermal cells, we identified nebbish (neb), a kinesin-encoding gene transcriptionally activated by jumu. Phenotypic analysis shows that neb is required for only two categories of jumu-regulated cardiac progenitor cell division: symmetric and cell division at an earlier stage. Synergistic genetic interactions between neb, jumu, Myb, and polo and the rescue of jumu mutations by ectopic cardiac mesoderm-specific expression of neb demonstrate that neb is an integral component of a jumu-regulated subnetwork mediating cardiac progenitor cell divisions. Our results emphasize the central role of jumu in cardiogenesis and illustrate how a single TF can utilize different combinations of other regulators and downstream effectors to control distinct developmental processes. 4. Using the D. melanogaster accessory gland as a model for prostate cancer S. Jaimian Church, Allison Box, and Laura Buttitta Presenting author: S. Jaimian Church University of Michigan Prostate cancer is the most common malignancy among elderly men. Prostate cancer affects 1 out of 7 men and is the second leading cause of cancer deaths for men in the United States. Drosophila melanogaster could be a useful rapidly aging model system for the study of human prostate cancer. The Drosophila accessory gland, (AG) is analogous to the human prostate, sharing similarities in the epithelium structure and organization, the cell types, and many of the same classes of seminal proteins are produced in both organs. It has been estimated that more than 70% of the genes thought to be involved in the human disease have orthologs in Drosophila. Their short lifespan means experiments take months rather than years as seen in aged mice models. To validate this model, we examined fly orthologs of oncogenic mutations known to occur in prostate cancer, such as hyperactivation of Myc or activation of Yki, the fly homolog of YAP, in the accessory gland epithelium. Our preliminary investigation found the overexpression of oncogenes was sufficient induce endocycling in the adult Drosophila AG, a tissue that is normally largely quiescent. Additionally, our models were able to recapitulate features of prostate cancer such as cellular and nuclear hypertrophy, expression of matrix metalloproteinases 1 (MMP1), mis-localization of cell-cell junction proteins, and apical/basal extrusions, that lead to abnormal glandular morphology. We are currently investigating which targets of Myc and Yki are responsible for gland hypertrophy and epithelial disruption.

5. Investigating the Nature of Transdetermination during Drosophila melanogaster Development Alison Smith, Charlie Vielee, and Justin Kumar Presenting author: Alison Smith Indiana University Bloomington During multicellular development, cells are in a pluripotent state though due to various cell signaling pathways and morphogen gradients cells begin to determine. When a cell does not adopt or retain the correct fate it can lead to various developmental anomalies. One way this happens is by transdetermination when a determined cell switches its fate to that of another tissue type without dedifferentiation. This process can be studied in Drosophila melanogaster via ectopic eye formation through the misexpression of the master retinal determination regulator eyeless (ey). For an ectopic eye to develop the cell must abandon its original fate to adopt a retinal fate. My preliminary observations indicate that ectopic eyes form through a biphasic state suggesting that for an ectopic eye to form, ey misexpression must meet certain criteria involving timing, distribution, and magnitude. Leading to my hypothesis that during transdetermination cells enter a biphasic state where depending on the temporal, spatial, and magnitude of a gene regulatory network misexpression, cells can readopt their original fate or proceed to their new fate. Using the UAS-GAL4 misexpression system I have shown that there is not only a critical spatial expression, developmental time, and expression level to which ey misexpression must occur for ectopic eye formation but also an uninvestigated requirement for ey expression in the eye antennal imaginal disc. I will further study these requirements for transdetermination with immunofluorescence, quantitative PCR, and single-cell RNAseq. Understanding the mechanism of transdetermination we can gain a better understanding of cell fate determination. 6. Using the DGRP to identify modifiers of hyperglycemia in the absence of sir2 Rebecca A.S. Palu Presenting author: Rebecca Palu Purdue University-Fort Wayne Variation in the onset, progression, and severity of symptoms associated with metabolic disorders such as diabetes impairs the diagnosis and treatment of at-risk patients. Diabetes symptoms, and patient variation in these symptoms, is attributed to a combination of genetic and environmental factors, but identifying the genes and pathways that modify diabetes in humans has proven difficult. A greater understanding of genetic modifiers and the ways in which they interact with metabolic pathways could improve the ability of physicians to predict a patient’s risk for severe symptoms, as well as enhance the development of individualized therapeutic approaches. In this study I used a Drosophila model of diabetes to identify candidate modifiers of hyperglycemia. Loss of the deacetylase SIRT1/sir2 induces obesity, hyperglycemia, insulin resistance, and general metabolic dysfunction, but these phenotypes are strongly dependent on genetic background. That variability made loss of sir2 an ideal model in a natural genetic variation screen through the Drosophila Genetic Reference Panel (DGRP). I monitored glucose levels in DGRP flies lacking sir2 expression and performed a genome-wide association analysis to identify natural genetic variants that are specifically associated with changes in hyperglycemia. Our preliminary results suggest that genetic variation similarly affects glycemia across age and feeding condition, and that this variation impacts pathways known to be influenced by Sir2 in the cell such as oxidative stress. We intend to validate these candidate modifiers individually and characterize more fully the impact they have on metabolic disease and their specific interactions with sir2.

7. Spatial and temporal cues of a stem cell direct the circuit partnership in Drosophila larval nerve cord Yi-wen Wang*, Christopher C. Wreden*, Jake Henderson, Maayan Levy-Bar; Jason L Mac-Lean, Ellie S Heckscher Presenting author: Yi-wen Wang U Chicago, MGCB One of the long-lasting questions in the neuroscience field is how circuits assemble starting from the level of neuronal stem cells. It is well-established that a small pool of stem cells generates widely diverse neurons through programs of gene expression—including spatial and temporal patterning. In contrast, how these spatial and temporal cues affect circuit assembly is poorly understood. This information will improve stem-cell based therapeutics for repair of damaged CNS. In this study, we examine stem cell derived spatial and temporal cues in neurons that synapses with each other by determining their stem cell origin and neuronal birth timing. We use the Drosophila larval sensorimotor system as a model, focusing on the neurons derived from neuronal stem cell NB3-3 and their presynaptic neurons. We applied electron microscopic connectome annotation of synaptic partnerships and advanced molecular genetic lineage tracing. Specifically, we characterize input connectivity for each neuron of NB3-3, and then determine stem cell origin and neuronal birth timing of both NB3-3 neurons and nerve cord interneurons that synapse onto NB3-3 neurons. The impact of this study is three fold. 1) It provides tools that will enable researchers to infer developmental origin of neurons in the Drosophila larval nerve cord. 2) It establishes NB3-3 as a powerful model system to study circuit assembly. 3) It suggests that the integration of spatial and temporal patterning information provides guidance for interneuron synaptic partnerships. Ultimately, our study revealed that the programs of gene expression known to promote neuronal diversity also regulate circuit wiring. 8. Drosophila JAK-STAT activity is a target of parasitoid wasp virulence strategies Susanna E. Brantley, Corinne M. Stouthamer, Pooja KR, Todd A. Schlenke, Nathan T. Mortimer Presenting author: Nathan T. Mortimer Illinois State University Innate immune responses that allow hosts to survive infection depend on the action of multiple conserved signaling pathways. Pathogens and parasites in turn have evolved virulence factors to target these immune signaling pathways in an attempt to overcome host immunity. Consequently, the interactions between host immune molecules and pathogen virulence factors play an important role in determining the outcome of an infection. The immune responses of Drosophila melanogaster provide a valuable model to understand immune signaling and host-pathogen interactions. Flies are commonly infected by parasitoid wasps and mount a coordinated cellular immune response following infection. This response is characterized by the production of specialized blood cells called lamellocytes that form a tight capsule around wasp eggs in their hemolymph. The conserved JAK-STAT signaling pathway has been implicated in lamellocyte proliferation and is required for successful encapsulation of wasp eggs. Here we show that activity of Stat92E, the D. melanogaster STAT ortholog, is induced in immune tissues following parasitoid infection. Virulent wasp species are able to suppress Stat92E activity during infection, suggesting they target JAK-STAT pathway activation as a virulence strategy. Furthermore, two wasp species (Leptopilina guineaensis and Ganaspis xanthopoda) suppress phenotypes associated with a gain-of-function mutation in hopscotch, the D. melanogaster JAK ortholog, indicating that they inhibit the activity of the core signaling components of the JAK-STAT pathway. Our data suggest that parasitoid wasp virulence factors block JAK-STAT signaling to overcome fly immune defenses.

9. Peroxisome-mediated liver-heart communication during Drosophila aging Kerui Huang, Hua Bai Presenting author: Hua Bai Iowa State University Despite its important role in redox homeostasis and fatty acid metabolism, the peroxisome remains the least understood among all intracellular organelles. Although recent studies show that peroxisomal function is impaired during the course of aging, the causal role of peroxisomal dysfunction in aging control remains elusive. Using Drosophila as a model system, we show that the translocation (or import) of peroxisomal matrix proteins declines in aged oenocytes (fly hepatocytes), which induces the production of pro-inflammatory cytokine upd3 (the fly homolog of interleukin 6) that signals to the heart to induce cardiac arrhythmicity. These findings reveal a novel role of hepatic peroxisomal protein import in non-autonomous regulation of cardiac aging. Intriguingly, we are able to genetically restore peroxisomal import function in aged hepatocytes by CRISPR/Cas9-mediated activation of Pex5, the key peroxisomal import receptor. Pex5 activation significantly blocks the production of pro-inflammatory cytokine upd3, and improves cardiac function with age. Thus, our studies establish peroxisome as a novel regulator of tissue aging and chronic inflammation (inflammaging). We propose that impaired peroxisomal function is not only an indicator (biomarker) of age, but also a major cause of tissue aging. 10. Endurance exercise ameliorates disease progression in Drosophila models of Spinocerebellar Ataxia Alyson Sujkowski, Kristin Richardson, R. J. Wessells, Sokol V. Todi Presenting author: Alyson Sujkowski Wayne State University Endurance exercise is a potent, broadly accessible intervention with widespread benefits proven to reduce disease incidence across species. While endurance exercise supports neural plasticity, enhanced memory, and reduced neurodegeneration, less is known about the effect of chronic exercise on the progression of movement disorders known as ataxias. Here, we focused on three different types of ataxias, Spinocerebellar Ataxias Type (SCAs) 2, 3 and 6, belonging to the polyglutamine (polyQ) family of degenerative disorders that also includes Huntington’s disease. In Drosophila models of SCAs 2, 3 and 6, flies progressively lose motor function and accumulate toxic levels of polyQ protein. Excitingly, we observe dramatic protection of speed and endurance in exercised SCA2 flies and modest protection in exercised SCA6 models, while no benefit is observed in SCA3 model flies. Importantly, accumulation of protein aggregates is reduced in SCA2 flies after chronic exercise, but not in SCA3 models, linking protein levels to exercise-based benefits. Currently, we are focusing on the activation of exercise mimicking-genes in SCA-model flies in order to define the mechanisms by which exercise preserves function in polyQ disorders. In preliminary experiments, the exercise-inducible protein Sestrin suppresses longitudinal declines in mobility in SCA2 flies, even without exercise. This study suggests differential responses of ataxia disorders to exercise, highlighting the potential for more extensive application of exercise-based therapies in the prevention of polyQ neurodegenerative progression. Defining the mechanisms by which exercise prevents disease progression will inform disease targets driving individual polyQ disorders, opening the door for more effective treatment.

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11. A confocal microscopy core facility for Midwest researchers featuring FLIM, spectral mapping, and adaptive deconvolution. Kevin Edwards, Alexander Diez, Mina Amini Presenting author: Kevin Edwards Illinois State University Illinois State University (Normal, IL) has opened a new bioimaging core facility available to researchers in the Midwest region (illinoisstate.edu/confocal). The ISU Leica SP8/White Light Laser system has several uncommon features that may be useful for special imaging needs, and these tools can synergize to enable new experimental approaches. Key technologies include: 1) Five fluorescence detectors, of which three are low-noise, photon counting Hybrid Detectors, allow simultaneous five-color imaging. 2) Full spectral mapping of samples to generate 2D excitation/emission plots (for excitations from 470-670 nm). This is useful for defining the behavior of dyes in an experiment or the autofluorescence characteristics of a sample. 3) Integrated adaptive deconvolution. Deconvolution of 3D image stacks enables resolutions under 200 nm; this requires minimal setup and works with any dye combination. 4) A resonant scanner permits 512 x 512 image collection at 28 frames/sec, suitable for live imaging. 5) Fully integrated fluorescence lifetime imaging (FLIM) with FLIM-FRET capability. This imaging mode is capable of distinguishing fluorochromes with similar emission spectra, and yields chemical information about the fluorochrome. 6) Confocal and epifluorescence modes can be directly compared using a sensitive cooled color CCD camera. 12. Characterizing Drosophila mutagen sensitive alleles through a collaborative Course-based Undergraduate Research Experience (CURE) Elyse Bolterstein, Kathryn P. Kohl, Eric P. Stoffregen, and Christina I. Swanson Presenting author: Elyse Bolterstein Northeastern Illinois University Course-based Undergraduate Research Experiences (CUREs) provide large-scale student training in answering original research questions that are of interest to the broad scientific community. By bringing research into the classroom, CUREs boost inclusivity within the sciences and provide authentic research experiences for students who may lack resources to engage in more intensive research fellowships. Further, CUREs are a sustainable mechanism for faculty at primarily undergraduate institutions (PUIs) to boost their research productivity and remain active in the research community. Our collaborative project brings together experts in DNA repair and replication from multiple PUIs to map and characterize mutagen sensitive genes in Drosophila through a series of classroom research modules (only 14 of the 58 discovered mutagen sensitive genes have been genomically mapped and characterized). The collaborative nature of this project allows undergraduate students in multiple biological disciplines to contribute to collective research on the function of the mus genes. Students at Winthrop University map mus genes using complementation crossing and have so far successfully mapped the gene mus109. Students in genetics and developmental biology at our other collaborating institutions work on mus109 mutant characterization including sensitivity to various DNA damaging reagents (Northeastern Illinois University), maternal effects (Lewis-Clark State College), and ovarian morphology (Arcadia University). In the past 3 years, our CURE has engaged nearly 200 undergraduate students, who have reported positive experiences and higher learning gains in these courses. Our future prospects include creating additional research modules for our CURE and expanding our network to involve additional researchers.

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13. Fly-CURE: A consortium of undergraduate genetics laboratory courses mapping and characterizing Drosophila EMS mutants Jamie Siders, Alysia Vrailas-Mortimer, Jacob D. Kagey Presenting author: Jacob Kagey University of Detroit Mercy A Flp/FRT EMS screen was conducted in the Drosophila eye in the context of blocked apoptosis to screen for conditional mutants that control cell growth and development. Using the mutants from this screen, we have established a classroom-based approach to the mapping and characterization of each mutant. This is done by undergraduate students within undergraduate genetics laboratory courses within the Fly-CURE consortium. The Fly-CURE consortium allows the data to be independently generated and confirmed by groups of undergraduate researchers at different institutions. From this project, undergraduate researchers have successfully mapped a number of EMS mutants, including alleles of Shn, Egfr, and Cos2. This data has led to local and national scientific presentations by students, as well as four peer-reviewed publications with student-generated data. To further our understanding of these mutants, we have established a protocol to use whole-genome sequencing in combination with deficiency mapping to identify mutations that do not fail to complement known alleles. To date, this project has involved over 400 undergraduate researchers within a classroom setting, providing research opportunities to students who may not have otherwise had exposure to authentic research experiences. Recently, we were awarded an NSF IUSE grant to expand this project to 20 total institutions involving over 800 undergraduate researchers in authentic genetics research. This project will measure the impact of the Fly-CURE on students’ attitudes toward research and measure the impact of research dosage and gains in learning objectives for students who take this course. 14. Update from the DGRC. Andrew Zelhof. 15. Update from the Bloomington Drosophila Stock Center. Cale Whitworth. 16. Update from FlyBase. Brian Calvi. 17. Genome Annotation of Contig1 in Drosophila ananassae Victoria Hodkiewicz, John Braverman, Sarah Elgin, Laura Reed, and Jennifer Jemc Presenting author: Victoria Loyola University of Chicago DNA packaging affects a gene’s availability for transcription. Typically, loosely-packed euchromatic regions are gene rich and exhibit higher levels of gene transcription, while densely-packed heterochromatic regions are gene poor and exhibit less gene transcription. The 4th chromosome, or F Element, of Drosophila is unique, as it contains ~80 genes and is heterochromatic in nature, yet these genes are actively transcribed. Thus, Drosophila species provide an ideal model system for exploring how genes are accessed in heterochromatic regions and how well these mechanisms are conserved over millions of years of evolution. Working alongside the Genomics Education Partnership (GEP), genes of the F Element and the control D Element are being annotated across Drosophila species to identify unique features of genes on the F Element. My work has focused on contig1 of Drosophila ananassae. We have annotated the coding spans (CDS) of contig1, which contains five genes located on the autosomal euchromatic 3L chromosome, including CG4911. While CG4911 encodes 3 isoforms, conservation analysis reveals that the PB isoform in not well-conserved in Drosophila ananassae. This annotation data will serve as control data for comparison to heterochromatic annotation data on the F Element. By performing these annotations, we are contributing data for analysis to understand why the heterochromatic regions of Drosophila’s fourth chromosome are able to be transcribed.

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18. Uncovering the context-dependent gene regulatory activities of Retinoblastoma paralogs in the fly wing Ana-Maria Raicu, David N. Arnosti Presenting author: Ana-Maria Raicu Michigan State University Retinoblastoma (Rb) family proteins are transcriptional corepressors that localize to promoter proximal regions of diverse classes of genes. Uncovering the mechanism of transcriptional repression by Rb proteins and their context specificity during Drosophila development is challenging due to the pleiotropic effects of global knockdown or overexpression of the factors. An in vivo approach to directly compare the activities of the fly Rb proteins on specific loci would provide the necessary setting to understand repressor selectivity and mechanism. To address this, we engineered flies expressing a nuclease dead Cas9 enzyme (dCas9) fused to the Drosophila Rbf1 and Rbf2 proteins and deployed them to diverse gene promoters in the developing wing tissue using guide RNAs. We found that Rb proteins can function in gene-specific ways when tethered to dCas9. When targeting the E2F2 promoter, wild type Rb proteins can mediate potent gene repression, while specific mutant versions have a more limited ability. Notably, a form of Rbf1 that lacks an “instability element” previously shown to be critical for activity of the endogenous protein is functional when tethered, pointing to the domain’s role in recruitment, rather than repression. In contrast, targeting the Insulin receptor promoter suggests an activating, or de-repressing, role by the Rbs. Using this dCas9-mediated approach, we will determine how genomic, temporal, and tissue-specific contexts impact the activities of these paralogs in the fly. The molecular analysis of promoter-specific regulation by diverse Retinoblastoma proteins will enhance our understanding of these conserved regulatory proteins in development and disease. 19. Wolbachia and virus alter the Drosophila transcriptome at the interface of nucleotide metabolism pathways Amelia Lindsey, Tamanash Bhattacharya, Richard Hardy, Irene Newton Presenting author: Amelia Lindsey University of Minnesota Wolbachia is a maternally transmitted bacterium that manipulates arthropod biology in myriad ways. The Wolbachia strain colonizing Drosophila melanogaster creates sperm-egg incompatibilities and protects its host against RNA viruses, making it a promising tool for vector control. Despite successful trials using Wolbachia-transfected mosquitoes for Dengue control, knowledge of how Wolbachia and viruses jointly affect insect biology remains limited. Using the Drosophila melanogaster model, transcriptomics and gene expression network analyses revealed pathways with altered expression and splicing due to Wolbachia colonization and virus infection. Included are metabolic pathways previously unknown to be important for Wolbachia-host interactions. Additionally, Wolbachia-colonized flies exhibit a dampened transcriptomic response to virus infection, consistent with early blocking of virus replication. Finally, using Drosophila genetics, we show Wolbachia and expression of nucleotide metabolism genes have interactive effects on virus replication. Understanding the mechanisms of pathogen blocking will contribute to the effective development of Wolbachia-mediated vector control programs.

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20. Intrinsic and extrinsic factors modulating the toxicity of the prion protein Fernandez-Funez P and Myers R Presenting author: Pedro Fernandez-Funez University of Minnesota Medical School, Duluth campus The prion protein (PrP) is an extraordinary protein responsible for devastating neurological disorders in humans and other mammals. PrP causes these conditions by misfolding and forming toxic aggregates that are also transmissible. An unresolved problem in the field is unraveling the mechanisms governing PrP conformational dynamics, misfolding, and the cellular mechanism leading to neurodegeneration. Available PrP sequences and 3D structures from different mammals provide a strong foundation to determine the impact of amino acid variations on PrP conformation and toxicity. The variable susceptibility of mammals to prion diseases is a natural resource that can be exploited to understand the conformational dynamics of PrP. Expression of PrP from different animals in flies shows preservation of their intrinsic properties: PrP from human and rodents are toxic whereas PrP from rabbit, horse, and dog PrP are not. Here we show that flies expressing human PrP result in new phenotypes in brain neurons and the eye. Using comparable attP2 insertions, we demonstrate the heightened toxicity of human PrP compared to mouse and hamster PrP and the specific interaction of human PrP with the amyloid-beta peptide. Finally, we uncover the importance of the PERK – ATF4 pathway of the unfolded protein response as a key cellular mechanism mediating the toxicity of human PrP. This new fly model expressing human PrP provides expanded opportunities to examine the impact of intrinsic (sequence / structure) and extrinsic (genetic) factors in regulating PrP toxicity. 21. Alcohol causes lasting transcriptome changes in Drosophila mushroom body neurons Emily Petruccelli1, Tariq Brown2, Amanda Waterman2, Nicolas Ledru3, Karla R Kaun2 Presenting author: Emily Petruccelli Southern Illinois University Edwardsville To better treat Alcohol Use Disorder, we need to identify how alcohol induces long-lasting transcriptional changes within specific cell-types linked to addiction. Drosophila melanogaster are an established model for studying the conserved neurogenetic and behavioral responses associated with ethanol exposure. Mushroom body (MB) neurons are a major associative memory center in the fly brain that are required for flies to develop maladaptive reward memories of intoxication experience, but the transcriptional changes occurring in these neurons were unclear. We isolated RNA from MB nuclei and performed RNA-sequencing to reveal the transcriptional states associated with ethanol reward memory. Flies were exposed to either repeated bouts of air, ethanol, odors, or ethanol paired with odors, and then allowed to recover overnight. Differential expression analysis revealed significant experience-specific changes at the transcript, but not gene, level. Eight particular transcripts were differentially expressed when flies formed associative memories of intoxication (ethanol paired with odors). This suggests that alternative splicing is an important mechanism by which memories are encoded and altered by ethanol exposure. One candidate, Stat92E, is known to interact with spliceosomal proteins, which suggests a possible means through which ethanol disrupts normal RNA processing. Current work is focused on functionally testing the spatiotemporal requirement of splicing- and Stat-related proteins in behavioral response to ethanol. Together this work highlights the lasting effects of repeated ethanol exposure on the MB transcriptome, and memory formation and expression. 1Southern Illinois University Edwardsville, Edwardsville, IL 2Brown University, Providence, RI 3Washington University, Saint Louis, MO

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POSTERS Room 1 – 3PM P-1. The Ecdysone response pathway controls differential regulation of the Hippo pathway that distinguishes two subtypes of post-mitotic photoreceptors Joseph Bunker, Pamela Boodram, Gerald Call, Jens Rister Presenting Author: Joseph Bunker University of Massachusetts Boston The steroid hormone 20-hydroxyecdysone (20E) regulates Drosophila metamorphosis by binding to the Ecdysone Receptor (EcR), a nuclear receptor that forms a heterodimer with the Retinoid X Receptor ortholog Ultraspiracle (Usp). This interaction activates canonical ecdysone responsive genes and directly regulates tissue-specific noncanonical ecdysone responsive genes, thereby eliciting differential downstream transcriptional responses in specific tissues and cell types. However, the precise mechanisms by which the EcR/Usp heterodimer controls differential transcriptional responses is not well understood. Here, we show that EcR/Usp control a differential transcriptional response that distinguishes two subtypes of post-mitotic R8 photoreceptors in the Drosophila retina. In one subtype, Hippo pathway activity is repressed transcriptionally (Hippo OFF photoreceptors), and in the other subtype, Hippo pathway activity is permitted (Hippo ON photoreceptors). The response of EcR/Usp to 20E is required for Hippo OFF photoreceptor fate, as R8 photoreceptor-specific expression of a dominant negative allele of EcR (EcRDN) or RNAi-mediated knockdown of Usp each cause a gain of Hippo ON photoreceptors and loss of Hippo OFF photoreceptors. Moreover, the canonical ecdysone responsive genes Blimp-1, Dhr3, and E75b are also necessary for Hippo OFF fate. Strikingly, specific RNAi-mediated knockdown of Blimp-1 isoforms containing exon 3, encoding a region of Blimp-1’s PR/SET domain, causes a loss of Hippo ON photoreceptors. Therefore, while Blimp-1 is required for Hippo OFF fate, expression of exon-3-positive isoforms of Blimp-1 promotes Hippo ON fate, indicating that differential expression of Blimp-1 isoforms may underly the differential response to 20E in the Hippo ON and Hippo OFF photoreceptors respectively. Room 1- 3 PM P-2. Structure function analysis of defective proventriculus (dve) in Drosophila melanogaster eye growth and development A. Chimata Venkatakrishnan, M. Kango-Singh, A. Singh Presenting Author: A. Chimata Venkatakrishnan University of Dayton During development, axial patterning is required to establish Antero-posterior (AP), Dorso-Ventral (DV), and Proximo-Distal (PD) axes, which is crucial for the generation of a 3-dimensional organ from a monolayer organ primordium. Of the three axes, DV axis is the first lineage restriction event during eye development and any deviation results in developmental birth defects. In our study, we have used Drosophila melanogaster (Fruit fly) eye as a model system to understand the role of different domains of a new dorsal eye fate selector gene, defective proventriculus (dve, an ortholog of SATB1) in growth and development. In humans, SATB1, functions as a transcriptional regulator and chromatin organizer and requires tetramerization by the ULD domain. In Drosophila eye, dve regulates expression of wingless (wg), a negative regulator of eye. In genetic hierarchy, dve acts downstream of GATA-1 transcription factor pannier (pnr) and upstream of wg. Loss-of-function of dve results in dorsal eye enlargement while gain-of-function results in eye suppression. We performed structure function analysis of Dve protein to elucidate the role of various domains in patterning, growth and differentiation. We have developed several transgenic lines, which will allow us to induce expression of the specific domains of Dve protein and assay their effect on Drosophila eye growth and development. Dve has a ULD domain for tetramerization, HOX domains for DNA binding and PPP4R2 domain for H2AFX

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dephosphorylation. Here we present our results on ectopic induction of these domains and their effect on eye phenotype and Wg expression in the developing eye.

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Room 1- 3PM P-3. A meiotic switch in lysosome acidity promotes spermatocyte development in young flies but collapses with age Tyler J. Butsch, Olga Dubuisson, Alyssa E. Johnson, K. Adam Bohnert Presenting Author: Tyler J. Butsch Louisiana State University Animal fertility requires the production of functional gametes. Understanding fundamental mechanisms that direct gametogenesis, and how they go awry with age, may reveal new entry points to combat infertility. Recently, we found that lysosomes activate during oocyte meiotic maturation in C. elegans, suggesting that a developmental switch in lysosome activity promotes female germ-cell health in young animals. Whether lysosomes are similarly regulated during sperm development is unknown. Using Drosophila melanogaster, we report that lysosomes activate in meiotic spermatocytes. In spermatocytes, active lysosomes turn over E-cadherin at endocytic foci to prevent germ-cell multinucleation. Importantly, we find that this function naturally declines with age as lysosomes lose acidity. In old testes, diminished lysosome acidity immediately precedes E-cadherin build-up and germ-cell multinucleation, and may contribute to age-related reproductive decline in males. These findings demonstrate that lysosome activity is tightly linked to meiotic progression in male and female germ cells, and hint that lysosomes may be key determinants of male reproductive aging. Room 1- 3PM P-4. Local inversion heterozygosity alters recombination throughout the genome Danny Miller, Scott Hawley, Nicole Crown Presenting Author: Nicole Crown Case Western Reserve University Crossovers (COs) are formed during meiosis by repairing programmed DNA double-strand breaks (DSBs) and are required for proper segregation of chromosomes. More DSBs are made than COs and those DSBs that are not repaired as a CO are repaired as noncrossovers (NCOs). The distribution of recombination events along a chromosome occurs in a stereotyped pattern that is shaped by both CO-promoting and CO-suppressing forces, collectively referred to as crossover patterning mechanisms. Chromosome inversions are structural aberrations that, when heterozygous, disrupt the recombination landscape by suppressing crossovers. In Drosophila species, the local suppression of COs by heterozygous inversion triggers a corresponding genome-wide increase in crossing over termed the interchromosomal (IC) effect. The molecular mechanisms of how heterozygous inversions suppress COs, whether NCOGCs are similarly affected, and what mediates the increase in COs in the rest of the gnome is completely unknown. By sequencing whole genomes of individual offspring from mothers containing heterozygous inversions, we show that, while COs are suppressed by inversions, NCOGCs occur throughout inversions at higher than wild-type frequencies. We confirm that CO frequency increases on the normal sequence chromosomes, yet CO interference remains intact. Intriguingly, NCOGCs do not increase in frequency on the normal-sequence chromosomes and the total number of DSBs is approximately the same per genome per meiosis. Together our data show that heterozygous inversions change the recombination landscape by altering the relative proportions of COs and NCOGCs and suggests that DSB fate may be plastic until a CO assurance checkpoint has been satisfied.

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Room 1-3PM P-5. Modeling a premature aging syndrome caused by a mutant form of Barrier-to-Autointegration Factor (BAF) in Drosophila. S. Cole Kitzman, Tingting Duan, Rebecca Cupp, Sri Thyagarajan and Pamela Geyer Presenting Author: S. Cole Kitzman University of Iowa The nuclear lamina is a protein meshwork that lies beneath the nuclear envelope and contributes to transcription, DNA replication and genome integrity. Dysfunction of the nuclear lamina causes many human diseases, including premature aging or progeroid syndromes. Recently, an atypical progeria syndrome called Néstor-Guillermo Progeria Syndrome (NGPS) was identified. In NGPS, patients prematurely develop hair loss, thin skin, bone loss and stiff joints, but do not develop cardiovascular or metabolic disease. NGPS is caused by mutation of BANF1, a gene encoding a conserved nuclear lamina protein that binds DNA, the nuclear lamina LEM-Domain (LEM-D) proteins, lamins, and histones. In NGPS, the mutated BANF1 gene encodes an Ala12Thr substituted Barrier-to-autointegration Factor (BAF). To understand the molecular pathogenesis of this early aging syndrome, we are using Drosophila, as Drosophila BAF is 65% identical to human BAF in amino acid sequence, including conservation of Ala at position 12. We are taking two approaches to understand the molecular defects of progeroid Drosophila BAF. First, we are defining biochemical properties. We have successfully purified wild type and mutant BAF proteins from bacteria and are testing the ability of these proteins to interact with DNA, LEM domains, lamin, and histones. Second, we are defining in vivo properties of NGPS dBAF. To this end, we engineered the progeroid mutation into the endogenous baf gene and are using these mutants to test effects of progeroid BAF on development and longevity. Together, these experiments are providing insights into how altered BAF function contributes to early aging phenotypes. Room 1 – 3PM P-6. CG10126, a Drosophila gene required for mitotic spindle stability and proper nuclear division B. Setu, S. Spencer Presenting Author: Bipul K Setu Saint Louis University Our lab is interested in Epidermal Growth Factor Receptor (EGFR)-directed cell proliferation in developing Drosophila. In a screen for transcriptional targets of EGFR activity, we identified a Drosophila gene, CG10126, that is upregulated 10-fold in response to EGFR activation. CG10126 is orthologous to human Calcyphosine (CAPS), whose expression is upregulated in many human cancer cells. Subsequent work from our lab reported that CG10126 is a tubulin binding protein that promotes microtubule polymerization and is localized along with mitotic spindle. From these observations, we hypothesized that CG10126 might be required for formation or stability of the mitotic spindle. To test this hypothesis, we knocked down CG10126 using RNAi in cultured Drosophila S2 and GM2 cells, followed by immunocytochemistry and imaging for analysis. We also compared control groups with the CG10126-dsRNA treated groups for cell viability, mitotic cell number, irregularities in metaphase spindles, and spindle length. In dsRNA-treated cells, we found significant difference in cell viability and in number of mitotic cells. A greater percentage of metaphase spindles were found abnormal and shorter in length. Our results suggest that CG10126 is required for proper assembly of the mitotic spindle and hints at a similar role of CAPS in human cells. Since CG10126 and CAPS are very similar, these findings could be further our understanding about fundamental aspects of mitosis and cell proliferation in human cells.

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Room 1-4PM P-7. The impact of E2F/Dp function on metabolism differs between muscles and fat cells Maria Paula Zappia, Ana Guarner , Robert Morris, Nadia Kellie-Smith, Alice Rogers, Brandon Nicolay, Myriam Boukhali, Wilhelm Haas , Nicholas J. Dyson and Maxim V. Frolov Presenting Author: Maria Paula Zappia University of Illinois at Chicago The E2F family of transcription factors functions as a key factor in controlling cell fate. The outcome depends mostly on the cellular context and environment. It was shown that E2F in muscles and in fat body is essential for animal viability in Drosophila. However, it is not clear whether the role of E2F is unique to each tissue. Here, we aim to determine the physiological impact of inactivating E2F in each tissue in vivo. Interestingly, our data imply that the role of E2F in muscles, but not in the fat body, has a systemic impact and could, consequently, explain its effect in animal development and viability. Furthermore, to uncover the mechanism of action of E2F in each tissue we investigated the similarities between E2F-deficient tissues by comparing the proteomic profiles between muscles and fat body. We found that E2F regulates carbohydrate metabolism, which was further validating by metabolomics. Next, food nutrient composition was disturbed to examine the effect of E2F loss in the context of carbohydrate metabolism. Our findings revealed that E2F was required in fat body to promote the storage of fat and the synthesis of trehalose, which was bypassed by feeding animals in high sugar condition. In conclusion, our data support a model in which the physiological impact of E2F functions vary depending on the tissue environment. Room 1-4PM P-8. Effect of Lead (Pb) on Drosophila melanogaster behavior- A new model for the studies on neurodevelopmental disorders Hunasanahally Puttaswamygowda Gurushankaraa, Olakkaran Shilpa, Anet Antony, Kizhakke Purayil Anupama, Shanthala Mallikarjunaiah. Presenting Author: Hunasanahally Puttaswamygowda Gurushankara Central University of Kerala and Bangalore University, India Lead (Pb) is a hazardous heavy metal ubiquitously present in the global environment. Its exposure during neurogenesis can induce oxidative stress, which plays a key role in the initiation of many neurodevelopmental disorders particularly autism spectrum disorder (ASD). This study investigates Pb induced oxidative stress and its influence on the onset of autistic like behavior in Drosophila melanogaster a model organism. Pb is accumulated in Drosophila reared in different sublethal concentrations of lead acetate (PbAc) treated food media. It induces oxidative stress by overproducing reactive oxygen species (ROS) and depletion of antioxidant enzymes. Pb induced oxidative stress alters behavioral patterns like grooming, learning and memory, locomotion, and social interaction as observed in ASD cases. This was evident from the RNAi-mediated silencing of superoxide dismutase (sod) and catalase (cat) antioxidant genes which caused severe behavioural defects, whereas, over-expression of cat and sod genes could ameliorate the behavioural alterations. Vacuolated regions in the neuropile area and cell bodies of Kenyon cells in the brain and increased DNA damage in neuronal cells of Pb exposed Drosophila suggests that Pb induced oxidative stress mediates the autistic like behavior in Drosophila. These results demonstrate the effect of the environment prevalent risk agent Pb on the behavior of Drosophila, and suggest the practicability and the ease of using Drosophila as a model in the studies of neurobehavioral developmental disorders.

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Room 1 – 4PM P-9. Long non-coding RNA regulation of spermatogenesis and endosomal processes via the spectrin cytoskeleton in Drosophila Mark Bouska, Hua Bai Presenting Author: Mark Bouska Iowa State University The spectrin cytoskeleton has been shown to be critical in diverse processes such as axon development and degeneration, myoblast fusion, and spermatogenesis. Spectrin can be modulated in a tissue specific manner through junctional protein complexes, however, it has not been shown that lncRNAs interact with and modulate spectrin. Here we provide evidence of a lncRNA that interacts with α and β Spectrin, is required for proper spermatogenesis, and is required for normal endosomal related activity in fat bodies of Drosophila. Our protein-RNA and RNA-protein biochemical analysis indicate α and β Spectrin complexes physically interact with the lncRNA CR45362. Immunohistochemistry revealed CR45362 is highly expressed in the basal testis while α and β Spectrin are disrupted in this same region of CR45362 mutants. We genetically demonstrate α-Spectrin and CR45362 deficiencies cause spermatid nuclear bundling defects in testis and reduced Lysotracker staining in the fat body. Our data suggests lncRNA regulation of spectrin could provide cells with a repertoire of modulatory molecules to manipulate cell-type specific cytoskeletal and endosomal requirements. Room 1-4PM P-10. Evolving a novel trait through co-option of the shavenbaby gene regulatory network Gavin Rice, Kenechukwu Charles-Obi, Mark Rebeiz Presenting Author: Gavin Rice University of Pittsburgh Network co-option is a process thought to facilitate novelty through the deployment of a set of interacting genes into a new developmental context. Most models of co-option suggest the existence of an upstream factor whose ectopic expression is sufficient to initiate the activation of an entire network in a new tissue. However, these transcription factors have seldom been identified, and their sufficiency to induce a trait has rarely been established. Here, we identify and validate an upstream network that was redeployed from a well characterized network to generate a novel morphological feature. Among Drosophila species, a wide variation of genital morphologies exist, including the phallus of Drosophila eugracilis, which is covered with over a hundred spike shaped structures that have been implicated in wounding females during copulation. The homologous tissue in Drosophila melanogaster lacks these spikes, providing a convenient outgroup for comparisons of development and genetic manipulations. We have found that the spikes in Drosophila eugracilis are produced by single cell extensions, similar to the small hairs (trichomes) that adorn the body in Drosophila. The transcription factor shavenbaby activates a well-studied network for trichome formation. We find that shavenbaby and its downstream targets are expressed in spike-forming tissues, suggesting the co-option of this network underlies this dramatic phenotype. We have also discovered that ectopic expression of shavenbaby in the phallus of Drosophila melanogaster induces phallic spikes. These results indicate that co-option of the shavenbaby network is sufficient for the gain of this dramatic novel trait.

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Room 1-4PM P-11. Regulation of Gonad Morphogenesis and Gametogenesis by the BTB Protein Ribbon Pauline Sulit, Shannon McDonnell, Adriana Soriano, Danielle Talbot, Manuel Alvarez, Usama Khan, Sana Moqeet and Jennifer Mierisch Presenting Author: Pauline Sulit Loyola University Chicago The Drosophila gonad has proven an excellent model for identifying genetic mechanisms underlying organogenesis. The gonad is formed when somatic gonadal cells and germ cells coalesce during embryogenesis. Subsequent development results in the establishment of the germline stem cell niche and stem cell populations that are maintained throughout the lifetime of the organism. Previously, the BTB transcription factor Ribbon (Rib) was identified as required for embryonic gonad formation. Further study revealed that Rib continues to be expressed during larval gonad development and in the adult ovaries and testes. These results suggest that Rib may regulate significant morphological changes that occur in the larval gonad and gametogenesis in the adult. We found that overexpression of rib in somatic cells throughout development causes defects in niche structure formation, resulting in ovaries with a blob-like appearance lacking eggs. To examine the role of Rib in oogenesis, rib overexpression was limited to the adult ovary. rib overexpression in somatic cells results in a reduction in the number of follicle cells surrounding the egg chamber and a failure of follicle cells to transition from endocycling to gene amplification. Examination of markers expressed during oogenesis reveals that Hindsight begins to be expressed early and expression persists in the egg chamber and Eyes absent expression persists in all follicle cells, consistent with defects in follicle cell development. Given that oogenesis arrests at a key transition regulated by the Notch signaling pathway, we are currently exploring the relationship of Rib and the Notch signaling pathway during oogenesis. Room 1-4PM P-12. Myosin II is required for Drosophila wing planar cell polarity Mariah Williams, Jessica Vanderploeg Presenting Author: Mariah Williams Taylor University One focus of developmental biology is understanding how cells are organized into tissues and organs. Planar cell polarity (PCP), one type of organization, is the process that coordinates polarity between neighboring cells within an epithelium. In vertebrates, disruption of PCP can lead to disorganization of auditory hair cells, fluid buildup in the brain due to disrupted cilia, and misoriented cell division leading to cysts in the kidney. In the Drosophila wing, PCP signaling dictates the orientation and parallel alignment of actin-rich hairs extending from the wing. Drosophila wing hairs are bundles of actin that protrude from an apical cytoskeleton ‘pedestal’ of microtubules (tubulin) and microfilaments (actin). This structure is important in proper wing hair localization, formation, and structural integrity. Disrupting the cytoskeleton early in hair development results in split hairs (termed multiple wing hairs) and abnormal positioning of the hair initiation site. However, it remains unclear if regulation of the cytoskeleton is required for continued development of PCP after hair initiation (eg. parallel alignment of wing hairs). Myosins are actin-binding motor proteins that regulate actin dynamics in the cytoskeleton. Here we test the hypothesis that non-muscle Myosin II (Spaghetti squash, Sqh) is required for parallel alignment of wing hairs. In this poster, we share progress from a summer undergraduate project looking at both pupal and adult analysis of loss-of-function sqh experiments.

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Room 2-3PM P-13. Characterizing slit function in PNS development Maria Pizarro Salazar and Afshan Ismat Presenting Author: Maria Pizarro Salazar University of St. Thomas Slit is a secreted ligand expressed in the ectoderm and plays an important role during neurogenesis. In the peripheral nervous system (PNS), removing slit results in a defect in the morphology and the migration of the lch5 chordotonal neurons. In order to gain a deeper understanding of how slit works in this developmental process, we have over-expressed slit in the neurons, glial cells, and ectoderm cells. Preliminary results show that over-expression of slit in glial cells resulted in some common defects, including an axonal branch from one section that connects to another and neurons that are completely out of place. Additionally, over-expression of slit in ectodermic cells show that the cluster tails from the dorsal section are shorter than the ones found in wild type embryos. Currently, we are in the process of over-expressing robo2 in these same cell types, as well as over-expressing slit in these different cell types in a slit mutant background. This data demonstrates the importance of slit in PNS development. Room 2-3PM P-14. Identification of Split-GAL4 drivers expressed in the Drosophila midgut. Ellen Popodi*, Jessica Holsopple*, Ishara Ariyapala*, Dalton Hartwick, Lily Kahsai, Kevin Cook, Nicholas Sokol *Equal contributors Presenting Author: Ellen Popodi Indiana University The Drosophila intestine is becoming an increasingly important model system. The four basic cell types of the intestinal epithelium generate significant regional diversity along the length of the gut. This self-renewing epithelium provides an excellent model to study cellular and molecular aspects of such tissues. Both the adult and larval gastrointestinal tracts are used to study interorgan signaling, microbiome interactions, immunity, energy balance and response to xenobiotic stress. To create more tools for studying the fly gut, the split-GAL4 drivers in 7304 stocks that were maintained at the BDSC in 2018 were screened for expression in the midgut by the BDSC and Nick Sokol’s lab. Using a novel intersectional strategy, each split-GAL4 driver was crossed to a complementary pan-midgut split driver with a 20xUAS-6xGFP reporter. Larvae and adults were examined for abdominal GFP expression and the midguts of expressing adults were characterized for regional expression. Drivers expressed in adults were also crossed to cell type specific split drivers to characterize expression patterns by cell type and region. We identified 590 drivers that were expressed in the intestine: 166 detected only in larvae, 232 detected in both larvae and adults, 192 detected only in adults. Two tables of scoring data (pan-intestinal and cell-type specific) and all associated images of whole intestine expression patterns are available on the BDSC web site https://bdsc.indiana.edu/stocks/gal4/midgut_splitgal4.html. You can navigate to the Split-GAL4 project page from our home page by accessing the GAL4/GAL80 page.

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Room 2-3PM P-15. A Role for Notch Signaling in Drosophila Spermatogenesis Adrianna Soriano, Jennifer Jemc Presenting Author: Adrianna Soriano Loyola University Chicago The Notch signaling pathway has diverse functions in male and female gonad development. In Drosophila male embryos, Notch specifies hub cell fate in somatic gonadal precursor cells, which are important for maintaining germline stem cells and somatic cyst stem cells throughout the lifetime of adult flies. However, a role for Notch signaling in adult males has only started to emerge recently. Others have demonstrated that Notch signaling appears to be necessary for the survival of the germline stem cell lineage. We have found that reducing Notch function with a temperature sensitive allele in adults results in the absence of hub-like structures in males, as well as defects in sperm bundle formation. In addition, overexpression of an activated Notch receptor in the somatic cells causes defects in spermatogenesis. Overexpression of activated Notch in somatic cells results in the presence of two or more hub-like structures in 57% males and testes with abnormal morphology. We also found that overexpression of activated Notch in somatic cells results in the continued expression of the transcription factor traffic jam (tj), an early somatic cyst cell marker, at later stages when tj expression is usually turned off. This indicates that the somatic cyst cells maintain an early somatic cyst cell identity. Consistent with a failure of somatic cyst cells to mature properly, we observe a failure of sperm bundles to form properly, indicating further defects in spermatogenesis. Currently, we are exploring when germline development arrests, and the mechanism by which Notch functions to promote spermatogenesis. Room 2-3PM P-16. Investigating the Roles of asteroid and Star during Oocyte Selection and Oogenesis in Drosophila Corinne Croslyn and Julie A. Merkle Presenting Author: Corinne Croslyn University of Evansville The intricate process by which gametes are formed from the germline stem cells is a fundamental question in biology. In Drosophila, oogenesis begins by asymmetric division of the germline stem cells, ultimately producing a cyst of 16 cells surrounded by a layer of somatic cells. One of these 16 germline cells is selected as the oocyte, the future egg, while the remaining become supporting cells. A genetic screen in Drosophila identified mutations in several evolutionarily conserved genes that result in a failure of oocyte fate determination, leading to loss of mature eggs and fertility. Strikingly, when the germline cells are mutant for Star (S) or asteriod (ast), the resulting cysts contain no oocyte. Further characterization of asteroid mutants revealed a persistence of double-stranded DNA breaks during meiosis. The protein encoded by ast and its human ortholog (ASTE1) both contain XPG domains, suggesting they act as nucleases, possibly during DNA repair. Interestingly, ASTE1 is mutated in a subset of patients with colorectal cancers, although its molecular function is yet unknown. To address the necessity of ast’s predicted nuclease-encoding domain during Drosophila oogenesis, we recently made a CRISPR-generated allele lacking the XPG domain. Surprisingly, loss of this domain does not result in severe defects during oogenesis in Drosophila. We are now investigating the relationship between S and ast by generating individual gene knockouts using CRISPR/Cas9 gene editing. Further insight into the roles of asteroid and S during oogenesis will shed much needed light on the molecular mechanisms controlling oocyte fate determination.

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Room 2-3PM P-17. JAK/STAT signaling regulates Defective proventriculus (Dve) to determine dorso-ventral patterning in Drosophila eye A. Raj, N. Gogia, A.V. Chimata, M. Kango-Singh, A. Singh Presenting Author: Akanksha Raj University of Dayton Long range signaling plays an important role in patterning and growth. During organogenesis, axial patterning is involved in delineation of Antero-Posterior (AP), Dorso-Ventral (DV) and Proximo-Distal (PD) axes. We employ Drosophila eye model to study the mechanisms behind DV patterning, which marks the first lineage restriction event. We have identified a new dorsal eye selector gene, defective proventriculus (dve, a Homeobox gene), an ortholog of SATB homeobox 1 (special AT-rich sequence binding protein 1), which controls expression of wingless (wg), a negative regulator of the eye development, to determine the head fate. Loss-of-function of dve results in dorsal eye enlargement by downregulating Wg, which is similar to the gain-of-function of JAK STAT signaling in the eye. Here we present that Unpaired (Upd), a long-range secreted ligand for JAK STAT pathway, plays an important role in DV patterning by regulating Dve expression in the dorsal eye. Gain-of-function of JAK STAT pathway in the eye disc exhibits dorsal eye enlargement by downregulating dve and its downstream wg. Conversely, inactivation of JAK STAT pathway causes dorsalization of the entire developing eye field due to ectopic induction of Dve and Wg in the ventral eye domain resulting in no-eye phenotype. Our data strongly imply that JAK STAT signaling plays a central role in DV axis determination by limiting the functional domain of the dorsal fate selector and thereby determine the boundary of eye versus the head field in the developing eye. Room 2-3PM P-18. Ptip, an essential component of the COMPASS-like H3K4 methyltransferase complex, is critical for proper cardiac cell division in Drosophila melanogaster AJ Farmer, Manoj Panta, Andrew J. Kump, Shaad M. Ahmad, and Kristopher R. Schwab Presenting Author: AJ Farmer Indiana State University Heart development requires precise spatiotemporal regulation of transcription governed by gene regulatory networks responsible for mesodermal induction, cardiac mesoderm-specification, and cardiomyocyte differentiation. These gene regulatory networks incorporate transcription factors and complexes that deposit epigenetic modifications onto chromatin to regulate gene expression. A key epigenetic modification associated with open and actively transcribed chromatin is Histone 3, Lysine (K) 4 methylation (H3K4me) which is mediated by the evolutionarily conserved COMPASS and COMPASS-like complexes. The BRCT-domain-containing protein, Ptip (Pax transactivation domain-interacting protein), recruits the mammalian COMPASS-like Lysine Methyltransferase 2C/D (KMT2C/D) and orthologous Drosophila melanogaster Trithorax-related (Trr) H3K4 methyltransferase complexes at gene loci to regulate gene expression. Furthermore, Ptip and the associated KMT2D H3K4 methyltransferase are essential for proper mouse heart development and gene expression patterns in adult cardiomyocytes. Global H3K4 methylation patterns have been previously shown to be diminished in mice and Drosophila lacking Ptip function. Given previous findings implicating Ptip in cardiogenesis, we investigated Drosophila melanogaster stage 16 heart cardiac cells in PtipMI03338 hypomorphs containing a MIMIC transposon predicted to truncate more than half of the Ptip protein. Quantitative analysis revealed numerous cardiac cell division defects that indicate disruption to both symmetric and asymmetric cardiac cell divisions. Therefore, our results suggest that Ptip is essential for proper cardiac cell differentiation during the formation of the Drosophila melanogaster heart. Our future experiments will investigate Ptip’s function in gene regulation, H3K4me, and genetic interactions with members of the COMPASS-like complexes in heart development.

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Room 2-4PM P-19. The role of fibulin in trunk visceral mesoderm development in Drosophila Courtney Peckosh, Afshan Ismat Presenting Author: Courtney Peckosh University of St. Thomas The visceral mesoderm of Drosophila melanogaster forms the layers of muscle fibers surrounding the digestive tract and performs contractions and exerts constant tension. An important component of this structure is the trunk visceral mesoderm (TVM) which gives rise to the circular muscle fibers that line the foregut, hindgut, and midgut. This structure develops through the rearrangement and elongation of cell clusters in the dorsal mesoderm along the anterior-posterior axis of the embryo. In this study, we are examining the role of fibulin (fbl) (CG31999) on the development of the TVM in Drosophila. Fibulin is a family of proteins in the extracellular matrix associated with elastic tissues and basement membranes. Knock-down of fbl in the entire embryo resulted in gaps in the TVM. Over-expression of fbl in the TVM or caudal visceral mesoderm (CVM) resulted in scattered and mis-migrating CVM cells. We are currently in the process of examining CVM migration in the absence of fbl. The continuation of this research is necessary for the determination of what causes the gaps to form, such as cells undergoing apoptosis or defects in the elongation process. Room 2-4PM P-20. The role of Jumu, a forkhead domain transcription factor, in mediating proper positioning of cardiac cells Manoj Panta, Andrew J. Kump, Neal Jeffries, Shaad M. Ahmad Presenting Author: Manoj Panta Indiana State University The development of a complex organ requires the specification of appropriate numbers of each of its constituent cell types as well as the correct positioning of these cell types within the organ. We show that the Forkhead/Fox domain transcription factors (TFs) Checkpoint suppressor homologue (CHES-1-like) and Jumeau (Jumu) are required for the correct positioning of cardiac cell types: null mutations in either gene result in the misalignment/incorrect positoining of cardiac cells within individual hemisegments. Using statistical analysis, we demonstrate that while some of these positioning defects are due to steric constraints, all CCs positioning errors cannot be solely explained by steric constraints. In order to find the downstream targets utilized by these Fox TFs to bring about correct positioning, we compared genome-wide transcription expression profiles of purified mesodermal cells from wild-type embryos and Fox mutants and identified 2,131 genes exhibiting significant differential expression in single or double Fox mutants. Our analysis also detected a significant overrepresentation of upregulated extracellular matrix (ECM) protein-encoding genes in the jumu mutants compared to wildtype embryos, raising the possibility that Jumu may be bringing about the correct positioning of cardiac cells by restricting the expression of ECM genes in the mesoderm. Our preliminary analysis of a subset of these Jumu TF-repressed targets suggests that our hypothesis is correct: ectopic overexpression of the ECM protein-encoding genes viking, Collagen type IV alpha 1, and terribly reduced optic lobes in the mesoderm of otherwise wildtype embryos phenocopies the cardiac cell positioning defects in the jumu mutants.

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Room 2-4PM P-21. Investigating the Role of COPII Vesicle Trafficking in Drosophila Oogenesis Darcie Smith*, Jenna Zirkelbach*, and Julie A. Merkle Presenting Author: Darcie Smith & Jenna Zirkelbach University of Evansville Cell fate determination has many unknown intricacies. Specifically, our understanding of many of the molecular mechanisms involved in gamete formation are still unclear. Research on ovarian development in Drosophila melanogaster will hopefully add depth to our existing knowledge. In Drosophila, the production of female gametes, called oogenesis, begins by asymmetric division of the germline stem cells, and ultimately produces a cyst of 16 cells. One of these cells is selected as the oocyte, the future egg, while the remaining become supporting cells. A genetic screen identified mutations in several evolutionarily conserved genes that result in a failure of oocyte fate determination, leading to loss of eggs and fertility. Sec24CD was identified in this screen and encodes an essential component of COPII vesicle trafficking, forming the inner vesicle coat. Surprisingly, few reagents are available to study components of COPII vesicle trafficking. To explore the role of COPII proteins in oocyte fate determination, we recombined a recently generated allele of Sec23 with an FRT to study its loss-of-function phenotype in the ovary using the Flp-FRT system. Recent results show that recombinant lines have been generated and future experiments will focus on examining the phenotype and comparing it to the Sec24CD mutant phenotype. We also cloned plasmids encoding gRNAs to establish CRISPR/Cas9-generated alleles of Sec23 and Sar1, a GTPase required for coat assembly. Understanding the role of COPII vesicle trafficking during oogenesis will not only shed much-needed light on oocyte fate determination, it will also aid in the understanding of animal fertility. Room 2-4PM P-22. Transcriptional regulation of the Insulin Receptor gene by FOXO and Ecdysone Ailton A Martins and David N Arnosti Presenting Author: Ailton A Martins Michigan State University The insulin receptor (InR) plays a central role in cell growth and development in Drosophila melanogaster. The roles of insulin signaling have been extensively investigated in the context of development, physiology, and evolution, but less is known about actual regulation of the gene itself. Both the FOXO signaling pathway and the ecdysone hormone regulate the InR gene on a transcriptional level. InR is around 50kb long, around 80% comprised of introns rich in transcriptional regulatory elements (Wei et al. 2016). We previously divided the InR introns in 25 fragments of ∼1.5 kb each, and tested the potential of these fragments to regulate expression of a reporter gene in cell culture. Interestingly, each fragment tested had a different effect on luciferase expression in S2 cells, functioning either as a repressor or activator. This differential response was also observed with the addition of FOXO and ecdysone. Here, we subdivided each of the 1.5kb fragments into 300 and 600bp subfragments, with the goal of better understanding their transcriptional regulation potential in S2 cells. We find that each 300 and 600bp enhancer subfragment has a different response compared to the larger fragment, and each has specific reactions to the addition of ecdysone or FOXO. The knowledge gained from this study can inform us about how InR transcriptional regulation works, and how mutations within regulatory sequences can impact the gene’s expression. These results also show that ecdysone and FOXO have a link, because of the similarity of responses to repression/activation for both.

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Room 2-4PM P-23. The role of the extracellular matrix protein fibulin on somatic muscle development Bronwyn Tollefson, Dr. Afshan Ismat Presenting Author: Bronwyn Tollefson University of St. Thomas Uncovering the genes that promote, block, and influence muscle development and connection has been a salient interest in modern day biological studies. Specifically, understanding the effect of genes on the somatic musculature of Drosophila melanogaster has provided many insights into not only the complexity at which organisms develop, but also potential solutions to human myopathies. In this study, we are studying Fibulin (Fbl) (CG31999), an extracellular matrix protein and its role in the somatic muscle development. After complete knock-down of fbl in the entire embryo using RNAi, our preliminary results showed morphological differences in somatic muscle patterning compared with controls. Over-expression of fbl in somatic muscles also displays muscle patterning defects, and, surprisingly, swollen and misshapen midguts. More time and research will solidify these findings and provide more insight into the complex relationship between Fibulin and somatic muscle development. Room 2-4PM P-24. SNPs associated with increased egg size in cold-adapted Drosophila melanogaster Tyler Hayes, Allison Hoefakker, Cecelia Miles Presenting Author: Allison Hoefakker Augustana University Egg size in Drosophila melanogaster is a highly polygenic trait and is closely related to fitness. We are using whole-genome sequencing (WGS) to gain insight into variation in this, and other polygenic traits. Three populations of flies were derived from a single common base population. Those include direct selection for small eggs, direct selection for large eggs, and indirect selection for large eggs. At this time we have sequence data for the indirectly selected, large-egg flies. Our aims for this project include 1) cross referencing sequence from replicate inbred lines derived from indirectly selected populations to a published candidate list of genes (Jha et al., 2015) based on the common base population 2) verify genes of interest present in both lists by examining phenotypic DGRP data and sequence (http://dgrp2.gnets.ncsu.edu/ ) 3) begin the process of validating putative SNP candidates by extracting DNA from individual flies to be followed by qPCR and 4) continue to analyze WGS data to include the directly selected fly lines. Room 3-3PM P-25. Integrity of a mitotic nuclear lamina is required in germline stem cells Tingting Duan, Rebecca Cupp, Pamela K Geyer Presenting Author: Tingting Duan University of Iowa Homeostasis of Drosophila germline stem cells (GSCs) depends upon the integrity of the nuclear lamina (NL). A compromised NL leads to a block of germ cell differentiation and GSC death due to activation of the ATR and Chk2 checkpoint kinases. Checkpoint activation occurs upon loss of the NL protein Drosophila emerin or its partner Barrier-to-autointegration factor, two proteins required for nuclear reassembly at the end of mitosis. To test whether checkpoint activation is linked to defective NL formation we investigated NL dynamics in GSC mitosis. These analyses led to the unexpected discovery that fGSCs utilize a non-canonical mode of mitosis, one that has a permeable, but intact nuclear envelope and NL. This mitotic NL contains Lamin and emerin and forms a ring-like structure that embeds centrosomes during mitosis. Loss of either Lamin or emerin causes spindle morphology and chromosome segregation defects. Notably, GSCs lacking emerin transmit mitotic defects into interphase, wherein centrosomes remain embedded in the interphase NL and retain large amounts of pericentriolar material. These observations reveal a new role for emerin in the regulation of centrosome structure. Furthermore, epistasis studies demonstrate that retention of pericentriolar material is

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upstream of checkpoint activation, suggesting that the failure to disassemble the mitotic centrosome triggers the checkpoint and causes GSC loss. Together, our data highlight a previous underappreciated role of the NL in mitosis in a stem cell population and suggest that integrity of the mitotic NL is required. Room 3-3PM P-26. Lipid droplets regulate actin dynamics via prostaglandin signaling during Drosophila oogenesis Michelle Giedt, Jonathon Thomalla, Michael A. Welte, Tina L.Tootle Presenting Author: Michelle Giedt University of Iowa Oocytes of many animal species have large amounts of lipid droplets which serve as an energy source for the developing embryo. In Drosophila, loss of the triglyceride synthesis enzyme DGAT1 causes sterility, and developing follicles display severe defects in actin remodeling and eventually die. We find that loss of several lipid droplet-associated proteins supports oogenesis but results in an unusual actin phenotype that includes faulty actin bundle assembly, disrupted cortical actin, and a failure of contraction, suggesting that lipid droplets serve an important regulatory function during oogenesis. This phenotype closely resembles that seen with loss of the cyclooxgenase-like enzyme Pxt, responsible for production of prostaglandins. Using dominant genetic interaction studies, we find that PLIN2 regulates actin remodeling independent of Pxt, whereas Jabba and Pxt, and ATGL and Pxt function in two distinct pathways to regulate actin. In mammalian cells, ATGL-mediated triglyceride breakdown can release arachidonic acid which subsequently serves as substrate for prostaglandin synthesis. We hypothesize that ATGL functions similarly upstream of Pxt. Preliminary lipidomics results indeed indicate the presence of arachidonic acid-containing triglycerides in ovaries. We are currently testing whether exogenous prostaglandin can restore actin remodeling and in vitro follicle development in atgl mutant follicles. These studies are among the first connecting lipid droplets to actin cytoskeletal regulation and suggest that one of the molecular mechanisms for this connection involves modulation of prostaglandin signaling. As lipid droplets, prostaglandins, and actin all have clinically relevant roles in many diseases, including cancer, these studies may help identify new therapeutic targets. Room 3-3PM P-27. Characterization of Circadian Rhythms in a DNA Repair Mutant "Elyse Bolterstein, Ph.D" , "Aaron E. Schirmer, PhD" Presenting Author: Gina Ishu Northeastern Illinois University The Drosophila gene, glaikit (gkt), is orthologous to human TDP1 which plays a role in DNA repair by removing DNA protein crosslinks. gkt mutants show phenotypes commonly associated with TDP1 mutations such as decreased motor abilities, shorter lifespan, and sensitivity to DNA damage reagents. Recent studies have demonstrated that excess night-time light, from sources like shiftwork and photopollution, alters circadian rhythms and may enhance levels of oxidative stress, leading to DNA damage. In order to better understand the interaction between DNA repair and circadian rhythms, gkt mutants and wild-type (w1118) flies were placed under different lighting schedules in order to assess changes in circadian and locomotor behavior. When comparing gkt mutants to w1118 under different lighting conditions, we see significant changes in behavior. These findings suggest that circadian rhythmicity may be altered in gkt mutants. Assessing circadian change in gkt mutants will allow for a better understanding of the relationship between circadian rhythmicity, TDP1, DNA repair, and cancer.

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Room 3-3PM P-28. Identifying genes and proteins that respond to Vitamin A deprivation in the eye Deepshe Dewett, Khanh Lam-Kamath, Maryam Labaf, Kourosh Zarringhalam, Andrej Shevchenko, Jens Rister Presenting Author: Deepshe Dewett University of Massachusetts Boston Vitamin A(vitA) is essential for vision and must be obtained through our diet. It forms retinal, a component of light-sensing Rhodopsin. VitA deprivation(VAD) severely disrupts the morphology of the photoreceptors, causes loss of the light-sensing pigments, and is the leading cause of preventable childhood blindness. However, little is known about how the eye responds to VAD at the molecular level. Using the Drosophila retina as a model, we aim to obtain fundamental insights into the molecular changes in the vitA deprived eye and to identify factors that respond to vitA deprivation to stabilize damaged photoreceptors. We raised flies on vitA-rich food(vitA+, contains beta-carotene as vitA source) or vitA-depleted food(vitA-). Through immunohistochemistry, we observed that VAD causes reduction in the size of the photoreceptors and defective opsin expression. Strikingly, however, we did not observe any photoreceptor death. We therefore hypothesized that protective factors are upregulated during VAD to stabilize Drosophila photoreceptors. Our total RNA analysis from heads of wild-type flies identified 68 differentially expressed genes (DEGs) between vitA+ and vitA- conditions. Gene Ontology analysis on these DEGs identified ‘phototransduction’ as an enriched category, including factors for Rhodopsin signaling(Arr1, Arr2) and retinal synthesis(ninaB, ninaG). Moreover, consistent with the proteome analysis performed by our collaborator Andrej Shevchenko(MPI, Dresden) we also detected a six-fold increase in the transcript levels of the novel gene mps in vitA deprived heads. Our validation experiments with mps null mutant, generated in our lab, revealed that the transmembrane protein Mps is upregulated in damaged photoreceptors and stabilizes them. Room 3-3PM P-29. mir-277 targets hid to ameliorate Aβ42-mediated neurodegeneration in Drosophila eye model of Alzheimer’s Disease P. Deshpande, C.-Y. Chen, C. Yeates, C.-H. Chen, M. Kango-Singh, A. Singh Presenting Author: Prajakta Deshpande University of Dayton Alzheimer’s disease (AD), an age-related progressive neurodegenerative disorder, exhibits reduced cognitive functions with no cure to date. One of the reasons for AD is the extracellular accumulation of Amyloid-beta 42 (Aβ42) plaques. We misexpressed human Aβ42 in the developing retina of Drosophila, which exhibits AD-like neuropathology. Accumulation of Aβ42 plaque(s) triggers aberrant signaling resulting in neuronal cell death by unknown mechanism(s). We screened for microRNA which post-transcriptionally regulate expression of genes by degrading mRNA of the target genes. In a forward genetic screen with candidate miRNAs, we identified mir-277 as a genetic modifier of Aβ42-mediated neurodegeneration. Gain-of-function of mir-277 rescues Aβ42 mediated neurodegeneration whereas loss-of-function of mir-277 enhances Aβ42 mediated neurodegeneration. Moreover, misexpression of higher levels of mir-277 in the GMR>Aβ42 background restores the retinal axonal targeting indicating functional rescue. Furthermore, we have identified head involution defective (hid) as one of the targets of mir-277 by Fly TargetScan and validated by luciferase assay and qPCR. The hid transcript levels are decreased by one third when mir-277 is misexpressed in the GMR>Aβ42 background in comparison to the GMR>Aβ42 fly model. Hence, here we provide a mechanism of how mir-277 modulates Aβ42 mediated neurodegeneration by regulating hid transcript levels and demonstrate its neuroprotective role in Aβ42-mediated neuropathology.

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Room 3-3PM P-30. Angiotensin (1-7) Expressing Lactobacillus displays Gender-Specific Effects on Cognitive Function in a Fly Model of Alzheimer’s Disease H. Smith, A. Smith, L. Roberts, G. Gorman, A. Verma, Q. Li, T. W. Buford, C. S. Carter, P. Jumbo-Lucioni Presenting Author: Haddon Smith Samford University Little progress has been made in identifying effective therapies for Alzheimer’s disease (AD). Our preliminary data suggest that pharmacological blockade of angiotensin (Ang)II production ameliorates cognitive deficits in a Drosophila AD model. Similarly, levels of Ang(1-7), a peptide with opposing actions to (Ang)II, has shown to inversely correlate disease severity in rodent AD models. Challenges are associated to Ang(1-7) administration but a novel method of delivering this peptide orally via a genetically modified probiotic(GMP) has proved bioavailable and effective in rodents. Drosophila represents an excellent in vivo model to study the effect of probiotics on complex disorders, like AD, in a high throughput manner. We hypothesize that GMP-based Ang(1-7)-supplementation ameliorates cognitive deficits in our fly AD model. We used a Drosophila line overexpressing the human amyloid precursor protein and the human β-site APP-cleaving enzyme in neurons. Lactobacillus paracasei producing Ang (1-7)(LP-A) was diluted in 5% sucrose. Optimal dilution, 1:2, was determined based on palatability. Flies were randomized to receive four 24-hour doses of LP-A or sucrose over 14 days. Cognition was assessed via an aversive phototaxic suppression assay. Regardless of supplementation, average food intake was significantly higher in AD males(p<0.0001). LP-A improved memory in AD males compared to unsupplemented cohort(p<0.02), but worsened cognitive function in AD females compared to those fed sucrose alone(p=0.03).Our findings suggest that the effects of a GMP-based Ang(1-7) supplementation on the cognitive function of a fly AD model are gender-specific. Sex-specific dosage optimization may be required to address this differential response. Room 3-4PM P-31. Protein-protein interactions regulate the toxicity of the Spinocerebellar Ataxia Type 3 protein Sean L Johnson, Bedri Ranxhi, Kozeta Libohova, Wei-Ling Tsou, Sokol V Todi Presenting Author: Sean L Johnson Wayne State University Spinocerebellar Ataxia Type 3 (SCA3) belongs to the family of polyglutamine (polyQ) neurodegenerative diseases. Each disorder stems from abnormal lengthening of a glutamine repeat in a different protein. Although caused by a similar mutation, polyQ disorders are distinct, implicating non-polyQ regions of disease proteins as regulators of pathogenesis.This protein context is a key determinant of polyQ toxicity. SCA3 is caused by polyQ expansion in the deubiquitinase, ataxin-3. Here, we sought to understand how non-polyQ regions of ataxin-3 regulate the toxicity of its expanded polyQ in SCA3. We utilized new allelic sets of Drosophila melanogaster expressing strategically truncated or full-length versions of the human ataxin-3 protein with specific mutations in its domains. These lines provided a base to build a more comprehensive picture of the relative contributions from each domain of ataxin-3. By utilizing fly genetics, physiology and biochemistry we found that ataxin-3 pathogenicity is saliently controlled by the polyQ-adjacent, ubiquitin-interacting motifs (UIMs), which markedly enhance its aggregation and toxicity. The UIMs function in part by interacting with the HSP70 chaperone superfamily member, Hsc70-4, whose reduction diminishes SCA3 toxicity in a UIM-dependent manner. According to additional results, Hsc70-4 also enhances pathogenicity of other polyQ proteins. Our studies provide unique insight into the relative impact of non-polyQ domains of ataxin-3 in SCA3, identify Hsc70-4 as an enhancer of polyQ toxicity, and indicate pleiotropic effects from HSP70 chaperones, which are generally thought to suppress polyQ degeneration.

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Room 3-4PM P-32. Temporal Clustering of Alcohol-Responsive genes in Drosophila Corinne Croslyn, Jenny Acevedo-Gonzalez, and Alfredo Ghezzi Presenting Author: Corinne Rebecca Croslyn University of Puerto Rico Alcohol abuse disorders are highly disabling conditions that provoke life-long struggles to over 30% of the US population. As a neural depressant, alcohol has the ability to cause long-lasting changes in the molecular identity of neurons within the brain through compensatory neuroadaptations of the nervous system. The link between how exactly casual consumption disrupts homeostatic function in the brain to perpetuate an addictive state, is still unknown. Our hypothesis suggests that alcohol exposure leads to long-term dynamic changes in gene expression in the brain that ultimately results in dysfunctional homeostatic neuroadaptations. To further understand how alcohol abuse perpetuates changes in neuroadaptation in the brain, analysis of the temporal transcriptional dynamics that occur in response to alcohol exposure will lead great insight into how gene expression is ultimately affected during alcohol abuse disorders. In order to observe how gene expression is progressively altered in response to alcohol exposure, the brains of D. melanogaster were dissected at days 1, 2, 3, 4, 6 and 7 after a single acute sedating dose of alcohol vapor and sequenced using RNA-seq technology. Clustering analysis of genes that showed significant changes in gene expression across time was performed to elucidate the different temporal transcriptional responses to ethanol exposure. The results demonstrate, that with 18 clusters comprising 4,191 genes total, there exists a wide variety of transcriptional responses to alcohol exposure. Room 3-4PM P-33. DnaJ family members tune memory Kyle Patton, Kausik Si Presenting Author: Kyle Patton Stowers Institute for Medical Research Long-term memory (LTM) involves the integration of many cues, both environmental and systemic. At a molecular level, these cues converge to cause changes in protein state, including expression and assembly, at the synapse. It has long been known that chaperones respond to changes in environmental conditions and also regulate folding and assembly of proteins. We are thus interested in determining whether chaperones may play a role regulating the formation and/or persistence of LTM by communicating changes in environmental or organismal states to synaptic translation machinery. Previous work from the lab has established that JJJ2, a Hsp40/DnaJ family member, is capable of promoting assembly of Drosophila Orb2/CPEB, a synaptic prion-like RNA-binding protein whose aggregation underlies the formation and persistence of LTM. Exogenous expression of JJJ2 in the fly also reduces the amount of training required to form LTM. Therefore, in order to determine whether any endogenous members of the fly Hsp40 family—the largest and most diverse family of chaperones—play a role in LTM, we have undertaken a screen involving overexpression and knockdown of the majority of fly Hsp40s in the mushroom body, the seat of memory in insects. In our preliminary studies, we have identified a discrete number of Hsp40/DnaJs whose altered expression has diverse effects on LTM without impairing short term memory. Future work involves determining whether/how these chaperones respond to environmental conditions as well as the molecular mechanism by which they influence synaptic memory machinery.

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Room 3-4PM P-34. The role of SIN3 in metabolism sensing and gene expression Imad Soukar, Lori Pile Presenting Author: Imad Soukar Wayne State University Metabolic homeostasis is an important aspect of cellular physiology, and the dysregulation of metabolism is a hallmark of many cancer types. The SIN3 complex is a global transcriptional regulator that is essential for cell viability and cell cycle progression. SIN3 serves as the scaffold for the complex; it binds many proteins through multiple interaction domains. Furthermore, data from our laboratory has shown SIN3 to have a regulatory function in many metabolic pathways. The mechanism through which SIN3 senses metabolic signals and regulates metabolic genes in response, however, is unknown. We are interested in how SIN3 can sense metabolic flux in the cell, and hypothesize that SIN3 is a metabolic sensor that affects metabolism by direct gene regulation of key metabolic enzymes. To manipulate metabolic flux in Drosophila S2 cells, we used 2-deoxyglucose (2DG) to block the early steps of glycolysis. Following 2DG treatment, we were able to identify metabolic genes that are regulated by SIN3 under metabolic flux disruption. Additionally, we identified SIN3 interactors by immunoprecipitating SIN3 from cells treated with 2DG, followed by LC-MS/MS analysis. Interestingly, many SIN3 interactors were differentially bound to SIN3 in 2DG treated cells compared to controls, indicating that the SIN3 complex undergoes a structural configuration change when metabolic flux is altered. These data support our proposed model in which SIN3 senses the metabolic status of the cell and binds to some new proteins while excluding others. Uncovering this mechanism will help us to better understand how epigenetic gene regulators impact cellular metabolism. Room 3-4PM P-35. Effects of the xenotopic expression of the mitochondrial alternative oxidase on Drosophila larval metabolism under cold-stress Geovana S. Garcia, Marcos T. Oliveira Presenting Author: Geovana Siqueira Garcia São Paulo State University, Brazil Alternative oxidases (AOX) are non-proton-pumping enzymes naturally absent in the mitochondria of vertebrates and insects. Its xenotopic expression in model organisms, however, can attenuate diverse phenotypes related to mitochondrial diseases, as the enzyme creates an extra pathway for oxygen reduction when the cytochrome c segment of the electron transfer system is overloaded. AOX is also known to function in thermogenesis, as its activity uncouples mitochondria. We have shown previously that Drosophila melanogaster expressing AOX ubiquitously develops faster and have higher larval and pupal viability than control flies at low temperatures. Here we show that AOX-expressing larvae are also more active at 12°C, and using infrared thermography that their body temperature is ~0.2°C higher. Larval whole body mitochondrial respiration shows that AOX-expressing flies have a ~30% decrease in glycerol-3-phosphate dehydrogenase (mGPDH)-driven oxygen consumption, which is compensated by a ~30% increase in complex I (CI)-driven oxygen consumption, at 12°C. AOX inhibition leads to a ~37% decrease in mGPDH-driven respiration, suggesting functional interaction between mGPDH and AOX. Because mGPDH is also a non-proton-pumping enzyme, this interaction would ultimately uncouple mitochondria, dissipating the energy of electron transfer as heat. Assuming that the increased CI-driven respiration may stimulate the reactions in the tricarboxylic acid cycle, which in the larvae would also stimulate cataplerosis and, consequently, larval growth, we also show here that AOX-expressing larvae cultured at 12°C accumulates ~12,5% more body mass. Our results suggest the cold-dependent AOX-induced developmental acceleration is caused by a combination of heat production via mitochondrial uncoupling and increased cataplerosis

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Room 3-4PM P-36. Differential Regulation of non-coding RNA (ncRNA) in aged Drosophila melanogaster in response to Infection by RNA Virus Eli Hagedorn, Lakbira Sheffield, Noah Sciambra, Alyssa Evans, Megan Delfeld, Casey Goltz, Janna Fierst, and Stanislava Chtarbanova Presenting Author: Eli Hagedorn The University of Alabama, Tuscaloosa, AL-35487 The model organism Drosophila melanogaster can elicit powerful innate immune responses against microorganisms including RNA viruses. Because of its short lifespan, Drosophila is amenable to study the mechanisms underlying the aging process. In humans, advanced age is associated with greater susceptibility and mortality to viral infections, as evidenced by the current pandemic caused by the RNA virus SARS-CoV-2. Although aging impacts on the innate immune system are well-characterized, the exact molecular events contributing to the more rapid death of the aged organism following viral infection remain incompletely understood. We found that aged Drosophila succumb faster to Flock House virus (FHV) infection compared to young, infected flies due to disease tolerance impairment. To investigate the molecular mechanism, we performed RNA sequencing and found that aged flies mount a larger transcriptional response following FHV infection than young flies, a response distinct from the transcriptional changes due to aging alone. Gene Ontology analysis revealed over 50% of differentially regulated genes for each experimental condition were uncategorized: without matching, specific biological processes. Among these genes several encoded for non-coding RNAs, including long non-coding RNAs (lncRNAs). We compared the expression of several lncRNAs via RT-qPCR and confirmed the differential expression specific to aged, FHV-infected flies. This indicates FHV infection affects the expression of lncRNA-coding genes, and specific lncRNAs are regulated in the aged organism after FHV infection. Our work shows that Drosophila can serve to model host-virus interactions during aging and allow analysis of lncRNAs’ function in survival to viral infection at older age. Room 4-3PM P-37. The G-protein signaling Rcp controls the polarized basement membrane deposition in epithelial cells Trent Davids, Tracie Yiqing Kong, Alejandro Salas, Trudi Schupbach, Olivier Devergne Presenting Author: Trent Davids Northern Illinois University Epithelial cells play important roles in the development and physiology of the human body, a key component of epithelial functionality is the establishment of apical-basal polarity (ABP) within the cells. A major component of the ABP is the basement membrane (BM), a mesh-like extracellular matrix of proteins that anchors epithelial cells and establishes the basal pole of the cell. BM proteins are specifically secreted basally by the epithelial cells. Despite its important roles, the overall mechanisms for the polarized deposition of the BM are currently poorly known. To study BM deposition we use the follicular epithelium (FE) of Drosophila melanogaster as a model system. In a genetic screen looking for new genes involved in the proper placement of BM proteins, we identified a new gene Rcp (Receptor component protein) involved in G-protein signaling. The loss of Rcp leads to the improper deposition of BM proteins at the apical side of the FE, and defects in epithelial architecture. Additionally, the knockdown of Rcp in the FE also leads to a strong apical accumulation of BM proteins supporting the role of Rcp in the proper placement of BM proteins. Interestingly, Rcp is the first component of a signaling pathway that has been implicated in BM polarity. We will describe the different approaches that we are undertaking to understand how Rcp controls the basal deposition of BM proteins in a polarized epithelium.

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Room 4-3PM P-38. The Role of Copper in Parkinson’s Disease J.S. Burkhart and A.D. Vrailas-Mortimer Presenting Author: Jessica Burkhart Illinois State University Parkinson’s Disease (PD) is a neurodegenerative disease caused by the death of dopaminergic neurons in the substantia nigra region of the brain. PD is characterized by the presence of dysfunctional mitochondria and increased levels of oxidative stress. Though a handful of genes, such as parkin and PINK1, have been identified in familial forms of PD, most cases are sporadic. Therefore, it is thought that environmental factors may act on genetic risk factors to promote disease onset. Therefore, we are exploring the relationship between copper toxicity, which has been linked to other neurological disorders, and parkin and PINK1. We are testing the effect of environmental exposure to copper as well as altering copper levels genetically by manipulating the copper transporter ATP7, which is mutated in the neurodegenerative disorder, Menkes disease. Room 4-3PM P-39. Effects of Artificial Preservatives Upon Drosophila sturtevanti Lifespan During Periods of Food Stress Connor J. Bryant and Jennifer M. Gleason Presenting Author: Connor J. Bryant University of Kansas The ability to survive starvation depends upon an organism’s ability to store and ration energy. For this reason, differences in body size affect starvation resistance. We performed a preliminary experiment to determine how long starved Drosophila sturtevanti live. Previous reports indicate that the presence or absence of preservatives makes a difference on how long D. melanogaster survive on non-nutritive agar. Given the differences in body mass between male and female D. sturtevanti, we hypothesized that the females would survive starvation longer than males. In addition, we hypothesized that flies would live longer on non-nutritive agar with preservatives than non-nutritive agar without preservatives. On average, females survived approximately 12 hours longer compared to males on unpreserved agar and survived 72 hours longer than males on preserved agar. The female flies on preserved agar survived approximately 144 hours longer than female flies on unpreserved agar while male flies on preserved agar survived approximately 60 hours longer than male flies on unpreserved agar. Results from this experiment establish the relationship between the life span of males and females during periods of starvation, as well as providing a timescale for further experiments involving D. sturtevanti behavior in periods of food stress.

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Room 4-3PM P-40. A Drosophila Model of Traumatic Brain Injury Andrea Monteon and Nicole Bournias Vardiabasis Presenting Author: Andrea Monteon California State University, San Bernardino Traumatic brain injury (TBI) is defined as a disruption in normal function of the brain caused by a bump, blow, or jolt to the head. The most common form of TBI is mild TBI (mTBI) also known as a concussion. While a single mTBI may not always induce impairment to the brain, recurrent mTBI (mrTBI) can cause long-term deficits such as neurodegenerative changes. Neurodegeneration is the progressive atrophy of neurons common in Alzheimer’s disease (AD). Generally, there is a great risk for developing AD as we age. However, mrTBI has been shown to increase the likelihood of developing the pathology. Another physiological change that occurs in response to aging is intestinal barrier dysfunction. Not only does normal aging result in intestinal barrier dysfunction, but mrTBI can also jeopardize intestinal barrier integrity. The known pathologies of Alzheimer’s include Aβ-42 plaques. Transgenic Drosophila melanogaster can express the human Aβ-42 polypeptide and have been successfully used as a research model for Alzheimer’s. To investigate the effects of mrTBI, Drosophila melanogaster expressing the Aβ-42 polypeptide and Drosophila melanogaster not expressing the Aβ-42 polypeptide, also known as OOCs, were used as a model for this experiment. Both Aβ-42 and OOC flies were subjected to mrTBI using two devices that mimicked the impact of TBI: the HIT device and the Omni Bead Ruptor Homogenizer. To analyze the effects of mrTBI, lifespan and health-span assays were performed. Preliminary results indicate that the Aβ-42 model can be successfully utilized to demonstrate brain damage inflicted by mrTBI. Room 4-3PM P-41. Characterization of CG4511 as a Novel Regulator of Spermatogenesis Claire Chaikin, Michela Marra, Stefan Kanzok, Jennifer Jemc Presenting Author: Claire Chaikin Loyola University Chicago In the malaria parasite Plasmodium berghei, Phosducin-Like Protein 3 (PhLP-3) exhibits redox activity and is hypothesized to function as a co-chaperone for cytoskeletal protein folding. In order to explore the role of PhLP-3 and its homologues in cytoskeletal regulation, we are examining the role of the Drosophila homolog, CG4511, in spermatogenesis. Drosophila spermatogenesis is an excellent model for studying cytoskeletal regulation given the requirement of actin and microtubules during multiple stages of spermatogenesis, and the ability to view multiple stages of spermatogenesis simultaneously. Following meiosis, the microtubule-based axonemes elongate and actin-rich individualization complexes (IC) aid in spermatid individualization and cytoplasm removal. Males homozygous for a P element insertion in CG4511 were found to be sterile and have reduced CG4511 expression levels compared to wild-type. In order to determine what is happening in spermatogenesis to cause this sterility, we examined sperm morphology in the distal testis and the seminal vesicle. At this stage, wild-type sperm individualize and nuclei exhibit a needle-like appearance. However, in CG4511 homozygous mutants individualizing sperm and needle-like nuclei were not observed and differential contrast microscopy revealed a lack of sperm bundles. In addition, seminal vesicles appeared smaller in size, consistent with decreased sperm production. Given the predicted function of PhLP-3 as a regulator of cytoskeletal protein folding, we performed phalloidin staining to visualize the actin-based structures. In CG4511 mutants, no actin cones, indicative of spermatid individualization, were observed. Further examination is needed to determine when spermatogenesis arrests and if the microtubules are affected by the mutation.

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Room 4-3PM P-42. Do D. melanogaster females change their sperm use patterns in response to perceived changes in male quality? Brooke Peckenpaugh and Leonie Moyle Presenting Author: Brooke Peckenpaugh Indiana University In addition to premating choices, females that mate multiply make postcopulatory choices about which sperm fertilize their eggs (cryptic female choice). However, it remains unclear how females make these choices, and what impact they have on female fitness. In this study, we test whether Drosophila melanogaster females adjust their sperm use patterns in response to altered precopulatory indicators of male quality—male pheromones—even when male postcopulatory contributions remain the same. To do this, we manipulated male pheromones to resemble either heterospecific (D. yakuba) males—thereby reducing their perceived quality as a mate—or to resemble their own genotype (as controls). We compare second male paternity (proportion of offspring sired) between treatment vs control males by mating each with females that have previously mated with a GFP-labelled tester genotype. We find that females of some genotypes use proportionally less sperm from males that are perceived as lower quality mates, suggesting that Drosophila females are capable of making postcopulatory choices based on precopulatory cues. Room 4-4PM P-43. Circadian rhythms in gut microbes of Drosophila melanogaster Teja Bhimavarapu, Haley Castle, Travis Leuzinger, Shianne Stacy, Paul Schweiger, and Alder Yu Presenting Author: Teja Bhimavarapu University of Wisconsin - La Crosse Circadian  rhythms  are driven by internal clocks that drive daily patterns in physiology and behavior. The gut microbiome in an organism consists of bacteria, fungi, and viruses. They help organisms digest food and secrete molecules that affect host physiology. In mammals the gut microbiome is shown to interact with circadian rhythms. The objective of the project is to see whether  a disrupted circadian rhythm in  fruit flies  (Drosophila melanogaster)  can change the relative abundance of bacterial species present in the gut microbiota. Guts were collected every 6 hours from flies kept under either 12:12 hours of light:dark or constant light. Circadian rhythms in flies do not function under constant light. Microbial DNA isolation was done by  QiaAMP  Fast DNA Stool Mini Kit. Microbial DNA was PCR amplified using universal 16S primers. We found that Gilliamella and Burkholderia bacteria varied in abundance between day and night. This variation in abundance was abolished under constant light conditions. Changes in abundance of Paenibacillaceae, Bradyrhizobiaceae, and Burkholderiaceae suggested statistically significant circadian rhythms. However, Wolbachia sequences interfered with detecting other genera of bacteria. We are currently repeating the study in Wolbachia free flies.

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Room 4-4PM P-44. Circadian Rhythm Disruption and DNA Repair Pathway Choice Caleb Fitzmaurice, Tyler Jeschke, Alder Yu Presenting Author: Caleb Fitzmaurice University of Wisconsin-La Crosse Many workers follow irregular work schedules that interfere with their sleep-wake cycle. Shift work involving exposure to light at night leads to circadian disruption. Long term shift work is associated with an increased risk of cancers. However, whether there is a direct link between circadian disruption and cancer risk is unclear. The objective of the current study is to determine if a light:dark schedule modeled after shift work schedules will alter the ability of fruit flies to repair damaged DNA. If a simulated shift work schedule interferes with DNA repair pathway choice in flies, the same could be true in humans. To compare DNA repair between flies on a normal 12:12 light:dark schedule and a shift work-like 8:8 light:dark schedule, we used the Rr3 system in which a DNA break is introduced in the middle of a DSRed gene. If the break is repaired by single-strand annealing it will restore gene function and the flies will fluoresce red. If the break is repaired by non-homologous end joining the flies will not fluoresce. We used this system to compare the ratio of single-strand annealing to non-homologous end joining repair events for flies on each schedule. Data analysis revealed there was no significant difference in repair for prescribed schedules. Future investigations will involve other strategies for simulating shift work. Room 4-4PM P-45. Glial control of motor behaviors in Drosophila larvae Rebecca L. McAvoy, Stephanie E. Mauthner, and W. Daniel Tracey, Jr. Presenting Author: Rebecca L. McAvoy Indiana University Glial cells are essential components of the nervous system that shape neural circuits underlying behavior. Previous studies reported glial regulation of extracellular ions that are predicted to serve as a form of cell-to-cell communication. Therefore, we hypothesize that changes in glial ion concentrations result in cell signaling events that underlie behavioral outputs. To test this hypothesis, we performed optogenetic manipulations that directly altered glial ionic gradients in Drosophila larvae and measured behavioral changes. Specifically, we expressed the light-gated anion channel GtACR1 or the thermal-gated cation channel dTRPA1 in glia, induced changes to ionic concentrations, and recorded immediate motor behaviors. Interestingly, GtACR1-expressing larvae performed a full body contraction, and dTRPA1-expressing larvae performed the opposite behavior, a full body relaxation or paralysis. To rule out the possibility that leaky ion channel expression in neurons was the basis of these motor behaviors, we used genetic methods to suppress neuronal populations from expressing GtACR1 or dTRPA1. For both channels, the behaviors persisted throughout the neuronal suppression, supporting that glia contribute to the motor behaviors. We performed immunohistochemistry on larval brain dissections and fillet preparations to identity which glial populations express GtACR1::YFP in the nervous system. We observed GtACR1::YFP expression in cortex and astrocyte-like glia of their brain lobes and ventral nerve cord of the central nervous system, and wrapping glia that ensheath sensory and motor neurons of the peripheral nervous system. Combined, our results support glial modulation of neuronal circuits that produce the accordion phenotype and full body relaxation, potentially through ion gradients.

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Room 4-4PM P-46. A novel approach to understanding the retinal degeneration in SCA7 in Drosophila Sokol Todi, Wei-Ling Tsou Presenting Author: Wei-Ling Tsou Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI Polyglutamine (polyQ) expansion mutations cause protein misfolding and aggregation and lead to neurodegenerative diseases. One of these diseases is spinocerebellar ataxia Type 7 (SCA7). SCA7 patients share similar motor symptoms with other polyQ ataxias. However, SCA7 patients also develop vision loss and the mechanism is unclear. The SCA7 disease protein, Ataxin-7, belongs to the transcriptional regulatory complex SAGA (Spt-Ada-Gcn5-Acetyl transferase). SAGA is an evolutionarily-conserved, multifunctional transcription co-activator that is made of 18–20 proteins. To understand whether neurodegeneration in SCA7 is caused by impairment of SAGA’s function, we first investigated the importance of SAGA components by systematically knocked down SAGA constituents only in neurons, only in glial cells, or only in muscles in Drosophila through RNA-interference. We further examined the photoreceptor connections to the optic lobe in larval eye discs. Several SAGA components are differentially required, suggesting that different subunits have specific roles in the developing fly or in adults. One of the Ataxin-7 interactors in SAGA, USP22, when knocked down specifically in glial cells in flies, causes abnormal morphology in the photoreceptors, including lower photoreceptor density, thinner axons and miss-targeting of photoreceptor axonal projections to the brain. Considering the close and direct physical association of USP22 with Ataxin-7 in SAGA, the question arises whether polyQ expansion in Ataxin-7 impedes the glial function of USP22 and its role in visual system development and function. We will explore the role of glia-visual system neuronal communication in SCA7 from the perspective of Ataxin-7 and USP22 in our future work. Room 4-4PM P-47. Gars gene mutation and Charcot-Marie-Tooth Disease Christa Hale, Alysia Vrailas-Mortimer Presenting Author: Christa Hale Illinois State University Charcot-Marie-Tooth (CMT) disease or peroneal muscular atrophy is a type of neurological disorder that can be inherited in an autosomal dominant, autosomal recessive, or X-linked manner. Peripheral nerves control the functions of sensation, movement, and motor coordination in the muscles and sensory organs. Symptoms are weakness in the foot and lower leg muscles, which eventually spreads throughout the body. CMT is caused by mutations in genes that produces proteins that are involved in the function and structures of the myelin sheath or peripheral nerve axon. Gars1 gene yields the instructions for the creation of Glycyl-tRNA synthetase. This enzyme adds the amino acid glycine to the tRNAs that code for glycine. Treatments includes physical and occupational therapy, narcotics, or use of orthopedic devices or surgery to ease the symptoms. Research is needed to learn how to prevent, treat, and cure it by identifying genes and proteins. Drosophila melanogaster (study organism) have 75% of human disease-causing genes. They have conserved disease pathways, good genetics, and are inexpensive. The objective is to study the impacts of over-expressed or inhibited CMT gene (Gars) in muscle function and structure. What behavior is observed when Gars levels are increased or decreased? How is muscular structure affected? Since locomotor functions decrease with age, I hypothesize that the loss of this gene causes slow walking, dragging body, and reduced climbing at younger ages than control flies, demonstrating an increase in weak muscles. Additionally, the over-expression of Gars leads to better performance in old flies compared to controls.

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Room 4-4PM P-48. The serotonin receptor 5-HT2A mediates nutrient-specific longevity Allyson S. Munneke and Scott D. Pletcher Presenting Author: Allyson S. Munneke University of Michigan A growing body of evidence suggests that sensory perception of specific environmental contexts is encoded by distinct neural states, and altering these neural states can influence lifespan. Conserved neuromodulators, such as serotonin, (5-hydroxytryptamine, or 5-HT), are emerging as important mediators of the effects of environmental perception on longevity. However, the specific neural states encoded by distinct serotoninergic signaling pathways and how those states influence lifespan remain unclear. With their relatively short lifespan and conservation of neuromodulators, Drosophila melanogaster provides a powerful system by which to dissect these neural states. Drosophila possess five receptors for serotonin, which are homologous to those found in humans (5-HT1A, 5-HT1B, 5-HT2A, 5-HT2B, and 5-HT7), and 5-HT receptor null mutants display a remarkable variability in their effects on longevity. Most interestingly, 5-HT2A mutants display a sexually dimorphic lifespan extension. Several behavioral measures of overall health were examined as readouts for the altered neural state induced by loss of 5-HT2A. Interestingly, these mutants do not exhibit broad changes in sleep or activity patterns or measures of climbing ability; however, 5-HT2A mutants display altered feeding behaviors. Specifically, 5-HT2A mutants alter total food consumption based on the availability of dietary protein, and the lifespan extension is dependent upon specific nutrient ratios. Together, these data indicate 5-HT2A interacts with the nutritional environment to alter lifespan. Given the high conservation of serotonin signaling across taxa, this work will provide important insight into the biological mechanisms governing longevity. Room 5-3PM P-49. CHARACTERIZATION OF THE NUCLEOLAR PROTEIN NOC1 IN APOPTOSIS INDUCED PROLIFERATION (AiP) Paola Bellosta, Valeria Manara, Francesca Destefanis Presenting Author: Paola Bellosta Ribosome biogenesis is a complex biological process that takes place in the nucleolus, an intranuclear compartment where the ribosomal genes organize ribosomal DNA (rDNA). The synthesis of ribosomes requires the intervention of a series of protein factors and ribonucleotide particles, and among these, the members of the Noc family (Noc1, Noc2 and Noc3), that in yeast, have been demonstrated to be fundamental for the transport of rRNAs in the maturation of ribosome subunits. In Drosophila, the Noc genes are conserved at the nucleotide and aminoacid levels but their function has not yet been characterized. Here we show that Noc proteins are necessary for Drosophila development. In addition, reduction of noc1 in cells of the imaginal disc results in cell death and to non autonomously induces proliferation, a mechanism know as apoptosis induced proliferation or AiP linked to the up-regulation of p53. Further analysis is currently ongoing to better understand the role of Noc(s) in protein synthesis and in the role of AiP in ribosomal gene a novel link to the function of p53 in ribosomapathies.

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Room 5-3PM P-50. Intestinal progenitor P-bodies maintain stem cell identity by suppressing pro- differentiation factors Kasun Buddika, Yi-Ting Huang, Alex Butrum-Griffith, Sam A. Norrell, Alex M. O’Connor, Viraj K. Patel, Samuel A. Rector, Mark Slovan, Mallory Sokolowski, Yasuko Kato, Akira Nakamura, Nicholas S. Sokol Presenting Author: Kasun Buddika INDIANA UNIVERSITY, BLOOMINGTON Post-transcriptional gene regulatory mechanisms allow cells to rapidly respond to extracellular fluctuations independent of nascent transcription. However, the role of these mechanisms in adult stem cell population maintenance and lineage commitment remain poorly characterized. In this study, we address this question by investigating the role of processing bodies (P-bodies), a key site of post-transcriptional regulation, in intestinal stem cells of adult Drosophila. We report that, in contrast to neighboring differentiated cells, these progenitor cells possess P-bodies that contain Drosophila orthologs of canonical mammalian P-body components DDX6, EDC3, EDC4 and LSM14A/B and are ultrastructurally organized in a “core-shell structure”. Using a targeted RNAi screen, we identified 100+ genes that affect normal P-body morphology including Patr-1, a gene that we found to be necessary for mature P-body assembly. Using both verified Patr-1 RNAi strains and newly generated Patr-1 loss-of-function alleles, we show that P-body assembly defects correlated with loss of intestinal progenitor cells. Transcriptomic analysis found that pro-differentiation genes were inappropriately expressed in Patr-1 mutant progenitor cells and this upregulation of differentiation genes was likely independent of the well-known transcriptional repressor escargot. Additional experiments validated that the precocious progenitor-to-EC differentiation was the leading cause of progenitor cell loss, and that this phenotype could be rescued by overexpressing escargot. Taken together, this work delineates a novel P-body-dependent post-transcriptional regulatory mechanism of pro-differentiation genes to ensure proper adult progenitor cell maintenance. Room 5-3PM P-51. Role of Maelstrom Phosphorylation in Developmental Regulation of Meiotic Crossover Formation and Patterning Christiana Wang, Nicole Crown Presenting Author: Christiana Wang Case Western Reserve University Meiosis is an important mechanism that generates genetic variation for sexually reproducing organisms through recombination. In order for an organism to successfully propagate its genetic material from one generation to the next, its genome must be properly delivered as gametes. Meiotic crossing over of DNA ensures proper homolog segregation by repairing programmed double-stranded breaks. Meiotic defects caused by chromosome structural variants are detrimental to reproduction. During the interchromosomal effect, heterozygous inversions suppress crossing over between affected chromosomes while increasing crossing over between normal chromosome pairs. These defects in chromosomal dynamics trigger the pachytene checkpoint, leading to a delay in prophase progression; it has been suggested that this delay in prophase causes the interchromosomal effect on recombination. However, whether the interchromosomal effect on crossing over is caused directly by defects in chromosome dynamics or indirectly by the delay in prophase remains unclear. We are distinguishing between these two hypotheses by investigating the distributions and frequencies of crossovers in Drosophila mutants when prophase is extended by utilizing maelstrom mutants that trigger the pachytene checkpoint independently of chromosome defects. We are analyzing the distribution and frequency of crossovers in these mutants and using confocal imaging data of the germarium to visualize the effects of maelstrom mutations on meiosis. Our data will provide insights into the mechanisms of the interchromosomal effect and reveal whether or not the interchromosomal effect is directly mediated by a delay in pachytene or, alternatively, mediated by disrupted CO control mechanisms.

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Room 5-3PM P-52. SIN3 isoforms differentially regulate energy metabolism and cell survival Anindita Mitra, Lori Pile Presenting Author: Anindita Mitra Wayne State University Temporal and spatial gene expression is necessary for cell viability and organismal development. Gene activity is regulated by histone modification patterns and positioning. SIN3 is an essential transcriptional regulator that acts as a scaffolding protein for a histone deacetylase (HDAC) complex. Two major isoforms of SIN3 exist in Drosophila, SIN3 220 and SIN3 187. Work from our laboratory has shown that these isoforms have distinct expression patterns and perform overlapping and distinct functions. Using Drosophila S2 cells expressing either SIN3 220 or SIN3 187, we identified isoform specific binding sites as well as gene expression patterns. Analyzing these expression profiles in cells expressing either one of the SIN3 isoforms, we noted that compared to SIN3 220, SIN3 187 expressing cells repress various cell cycle and mitochondrial maintenance genes and activate several pro-apoptotic genes. Here, we are interested in studying the regulation of energy metabolism and survival by the SIN3 isoforms. We observed that cells expressing SIN3 187 exhibit higher susceptibility to oxidative stress as compared to cells expressing the SIN3 220 isoform. We also determined that the SIN3 187 expressing cells have lower oxygen consumption capacity, indicating possible mitochondrial dysfunction. We are interested to further analyze the link between the differential gene expression patterns and cell physiology. Together, these studies will help us understand how SIN3 187, compared to SIN3 220, mediates a differential response to cell survival. Results from these studies are expected to identify molecular mechanisms used by the SIN3 isoforms to control cell viability and energy metabolism. Room 5-3PM P-53. Gene Annotation of Heterochromatic DNA in Drosophila ananassae Trisha Patel, John Braverman, Sarah Elgin, Laura Reed, and Jennifer Jemc Presenting Author: Trisha Patel Loyola University- Chicago Heterochromatic regions are tightly packed and gene poor. While heterochromatin is associated with gene silencing, there are many examples of genes in heterochromatic regions that are expressed in a temporal and spatial manner. One example is the fourth chromosome, or Muller F element, of D. melanogaster. The D. melanogaster F element contains ~80 genes and is largely heterochromatic. While the position of genes on this chromosome is largely conserved across Drosophila species, there are unique examples of F element expansion due to the presence of increased repeat sequences. The project's goal is to provide insights into the evolutionary impacts of changes in chromosome and gene size, which will facilitate the identification of characteristics that enable genes to be expressed in a heterochromatic environment. In order to achieve this goal, it is necessary to have high quality gene annotations for genes on the heterochromatic F-element and the control D-element for comparison across Drosophila species. As part of the Genomics Education Partnership (GEP), we annotated two genes, CG7458 and Chitin synthase 2 (Chs2), located on the control D element, using Drosophila melanogaster as a reference species. Interestingly, CG7458 in D. ananassae had one fewer coding exon than reported for the D. melanogaster annotation due to the merge of two coding exons. This annotation was supported by RNA-Seq data and sequence conservation. These annotations will contribute to an understanding of how eukaryotic genomes become so large as well as help identify DNA characteristics for the regulation of genes in heterochromatic regions.

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Room 5-3PM P-54. Yorkie facilitates cell survival during larval eye development in Drosophila melanogaster Brooke Allen, Tiffany Cook, Jacob Kagey Presenting Author: Brooke Allen University of Detroit Mercy We are using the Drosophila eye as a model system because it is a well characterized developmental model. YAP1, the human homolog of Yki, is a transcription factor that has been found to be highly expressed and localized in the nucleus of several human cancers. To understand how key signaling pathways result in furrow progression and cell survival we are primarily focusing on the time-dependent knockdown of the transcription regulatory protein Yorkie (Yki) by utilizing both RNAi and the Flp/FRT systems to disrupt expression. Previous studies have shown Yki to be involved with cell survival, growth, and proliferation, though many of those studies have been in genetic systems in which Yki is overactive. We show that Yki is essential for survival and Yki knockdown results in increased cell death in larval discs, disrupted ommatidia in pupal discs, and smaller adult eye phenotypes. To investigate additional potential roles of Yki in eye development we used the FLP/FRT system to create mosaic eyes where clones have both a loss of Yki expression and a block in the canonical apoptotic pathway. The Yki/ark mosaic eyes show a rescue of clone size in both larval and adult eyes. Contrary to the understood role of Yki involved with cell growth and cell cycle regulation we see no disruption in patterns of mitosis, differentiation, or other developmental signaling pathways. Our studies suggest that while Yorkie may facilitate overgrowth and over-proliferation in certain mutant genetic contexts, that its role in early eye development is primarily cell survival. Room 5-4PM P-55. Conservation of CtBP Corepressor C-terminus from Flies to Mammals Dhruva Kadiyala, Madeline Niblock, Kayla Bertholf, Yahui Yang, Kalynn Bird, Akshay Seenivasan, Aanchal Jain, Ana-Maria Raicu, and David N. Arnosti Presenting Author: Dhruva Kadiyala and Madeline Niblock Michigan State University Department of Biochemistry and Molecular Biology The C-terminal Binding Protein (CtBP) is a transcriptional corepressor protein conserved across many lineages. This factor regulates gene expression and functions as a tumor suppressor. The structure of the CtBP catalytic core has been studied and shown to resemble an NAD(H)-dependent dehydrogenase, which can form dimers and tetramers. The significance of the structurally uncharacterized CtBP C-terminal region, and whether it is required for CtBP’s gene regulatory activities, is not well understood. Drosophila melanogaster has a single CtBP gene with multiple splice isoforms that encode variant “short” and “long” C-terminal isoforms that are differentially expressed in development. Here, we use an evolutionary approach to explore the conservation of the C-terminal tail using cDNA and genomic sequences from diverse arthropods and mammals. Among insects, we find that short isoforms are expressed only in certain orders, suggesting that the long isoform is the ancestral form. Within insects, multiple sequence alignment analysis reveals several deeply conserved hydrophobic and proline-rich motifs within the variable C-termini. Mammalian CtBP sequences also reveal variable C-termini in CtBP1 genes, with “short” isoforms apparently encoded by a separate gene, CtBP2, in some species. We will discuss the similarities of conserved motifs found in insects and mammals, and speculate on the functional relevance of those portions of the C-terminus. Our evolutionary approach can reveal possible regulatory significance of this divergent domain of a highly conserved metazoan transcriptional corepressor.

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Room 5-4PM P-56. Characterizing the Molecular Function of the Drosophila melanogaster Mutagen Sensitivity Gene, mus109 Vada Becker, Chandani Mitchell, Jordan DeLoach, Kathryn Kohl Ph.D., Elyse Bolterstein Ph.D. Presenting Author: Vada Becker Northeastern Illinois University DNA repair pathways are essential in repairing damage that otherwise could cause genomic instability and cancer. Because mutations in DNA repair genes are linked to numerous human diseases, elucidating the molecular functions of DNA repair pathways will improve our understanding of the disease mechanisms. Drosophila melanogaster has orthologs to most human DNA repair genes, so we can study mutants with reduced DNA repair function to investigate mechanism. Our work investigates the function of mus109, a Drosophila gene thought to be involved in DNA repair because allelic mutants are sensitive to various DNA damaging reagents. There are three available mus109 mutant alleles: the lethal mutant loss of function allele mus109lS, and the hypomorphic alleles mus109D1 and mus109D2. Our collaborators at Winthrop University used complementation crosses of these mutant alleles to map the location of mus109 on the X chromosome and confirmed mutant sensitivity to the DNA alkylating reagent methyl methansulfonate(MMS). We performed a protein sequence alignment comparing mus109 mutant alleles and found that mutations in each allele result in a loss of nuclease and/or helicase domains. To elucidate mus109 involvement in various DNA repair pathways, we tested larval sensitivity of different allele combinations to DNA damaging reagents. We have preliminary data suggesting that mus1091S/mus109D1 and mus1091S/mus109D2 larvae are sensitive to bleomycin, which causes double-strand breaks, but mus109D1/mus109D2 larvae are not sensitive to the single-strand break-inducer, camptothecin. We plan to assess mutant larval sensitivity to the replication fork staller, hydroxyurea to determine if mus109 is involved in other DNA repair pathways. Room 5-4PM P-57. Linking motor neuron synaptic structure and axon degeneration in Drosophila via the transmembrane protein Raw TJ Waller and Catherine Collins Presenting Author: TJ Waller University of Michigan c-Jun N-terminal Kinase (JNK) signaling plays central roles in neuronal stress responses, including both regeneration and degeneration following axon damage. At the Drosophila larval neuromuscular junction (NMJ), increased JNK activity can lead to both overgrowth at the NMJ and delayed axon degeneration following injury. The transmembrane protein Raw is a negative regulator of JNK signaling and our recent work found that its loss results in a delay in neurite degeneration following injury (Hao et al., 2019, PMID: 31492772). This delay is dependent on the JNK-target transcription factor Fos, which is also required for the delayed degeneration seen following a conditioning injury (Xiong and Collins, 2012, PMID: 22238096). Based on these data, it seems likely that Raw negatively regulates a transcriptional program that protects neurites from degeneration. To understand Raw’s cellular mechanism we have investigated its relationship with the Tricornered kinase (Trc), which shows genetic interactions with Raw during dendrite patterning (Lee et. al., 2015, PMID:25480915). I recently found that synapse morphology and degeneration phenotypes caused by knockdown of Raw are rescued in neurons that express constitutively active myristoylated Trc. These preliminary findings bring new attention to Trc for potential cross-talk with JNK signaling, axon degeneration, and adhesion.

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Room 5-4PM P-58. Comparison of the coding sequence of raptor in 27 Drosophila species Leon Laskowski, Brittany Cook and Jacqueline Wittke-Thompson Presenting Author: Leon Laskowski and Brittany Cook St. Francis College Drosophila is a model organism used to study the insulin pathway as this pathway is highly conserved across eukaryotes, including molecular components and physiological responses. D. melanogaster was one of the first species to have a completely sequenced genome available. Raptor (RPTOR) binds with additional proteins to form TOR-C1, which activates (or inhibits) many proteins downstream of the insulin signaling pathway. If there is selective pressure maintaining the function of RPTOR, then the structure of the raptor gene will be highly similar between Drosophila species and will not change with increasing evolutionary distance from D. melanogaster. The raptor ortholog was identified and its CDS (Coding DNA Sequence) in 27 Drosophila species were annotated using Flybase, NCBI Blast and GEP UCSC Genome Browser, and verified using Gene Model Checker. The CDS of the raptor ortholog for 19 of the 27 Drosophila species were analyzed for conservation in the coding DNA alignment using Multipipmaker. Species closer to D. melanogaster had higher percent identity (D. sechellia 98.3%) than species more distantly related (D. busckii 65.9%). Across all Drosophila species, three highly conserved regions (Raptor N-terminal domain, HEAT repeat motifs, and WD40 repeat motifs) were identified. These regions have been shown to be essential for protein-protein interaction with the TOR-C1 complex. Although overall percent identity decreased as evolutionary distance increased, structural and functionally essential regions within Drosophila were not strongly influenced by evolutionary distance. Therefore, selective pressure likely maintained the function of RPTOR due to its importance in the insulin signaling pathway. Room 5-4PM P-59. Investigating the Role and Activity of Stat92E in Flies’ Response to Alcohol Erica Periandri and Emily Petruccelli Southern Illinois University Edwardsville Alcohol use disorder (AUD) is a serious health problem that impacts millions. It is challenging to develop effective AUD treatments and therapies, because unlike other abused substances, alcohol disrupts a variety of molecules, including those involved in neuroimmunity and transcription. A recent transcriptomic study modeling alcohol addiction in Drosophila identified differential expression of signal transducer and activator of transcription protein at 92E (Stat92E), a transcription factor involved in the evolutionarily conserved Janus kinase (JAK)/STAT signaling pathway. When flies made alcohol reward memories, preferential isoform expression switched from Stat92E-RI (a negative regulator of the JAK/STAT pathway) to Stat92E-RH, suggesting that repeated alcohol exposure causes lasting Stat92E activation. Innate immune signaling can bidirectionally influence naïve alcohol response, but the functional relevance of Stat92E in naïve or repeated alcohol exposure is unknown. To address this, we measured alcohol-induced behaviors in naïve or pre-exposed flies with ubiquitous or pan-neuronal Stat92E RNAi knockdown. Interestingly, Stat92E was required for normal alcohol-induced locomotion in the pre-exposed condition, but not in the naïve condition. Compared to genetic controls, pre-exposed Stat92E-RNAi flies showed behavioral sensitization (increased responsivity to repeated stimuli), which is a hallmark of addiction in rodents and humans. Current work is focused on testing the role of Stat92E in volitional alcohol consumption, measuring Stat92E isoform expression, and using a STAT-GFP or -dGFP reporter to measure STAT activity in the brain in response to alcohol. Ultimately, understanding the role of STAT signaling in the brain as it relates to alcohol exposure will help develop therapeutic strategies for AUD. 1Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL 62026

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