conservation genetics of disjunct populations of cotton rat … · 2011-10-22 · conservation...
TRANSCRIPT
![Page 1: Conservation genetics of disjunct populations of Cotton Rat … · 2011-10-22 · Conservation genetics of disjunct populations of cotton rats (Sigmodon) along the Lower Colorado](https://reader033.vdocument.in/reader033/viewer/2022060312/5f0b2ccb7e708231d42f37c8/html5/thumbnails/1.jpg)
Conservation genetics of disjunct populations of cotton rats (Sigmodon)
along the Lower Colorado River
Sean A. NeiswenterChris DodgeAllen Calvert
Brett R. Riddle
![Page 2: Conservation genetics of disjunct populations of Cotton Rat … · 2011-10-22 · Conservation genetics of disjunct populations of cotton rats (Sigmodon) along the Lower Colorado](https://reader033.vdocument.in/reader033/viewer/2022060312/5f0b2ccb7e708231d42f37c8/html5/thumbnails/2.jpg)
Introduction • Sigmodon arizonae • Sigmodon hispidus
![Page 3: Conservation genetics of disjunct populations of Cotton Rat … · 2011-10-22 · Conservation genetics of disjunct populations of cotton rats (Sigmodon) along the Lower Colorado](https://reader033.vdocument.in/reader033/viewer/2022060312/5f0b2ccb7e708231d42f37c8/html5/thumbnails/3.jpg)
Introduction
• S. hispidus – McClenaghan 1979– Kessler and Avise
1985– Pfau et al. 2001– Phillips et al. 2007
• S. arizonae
![Page 4: Conservation genetics of disjunct populations of Cotton Rat … · 2011-10-22 · Conservation genetics of disjunct populations of cotton rats (Sigmodon) along the Lower Colorado](https://reader033.vdocument.in/reader033/viewer/2022060312/5f0b2ccb7e708231d42f37c8/html5/thumbnails/4.jpg)
Introduction
• Objectives– Identify populations of Sigmodon along the
LCR
– Determine genetic structure of populations along the LCR
– Determine how unique the populations are compared to the rest of the range
![Page 5: Conservation genetics of disjunct populations of Cotton Rat … · 2011-10-22 · Conservation genetics of disjunct populations of cotton rats (Sigmodon) along the Lower Colorado](https://reader033.vdocument.in/reader033/viewer/2022060312/5f0b2ccb7e708231d42f37c8/html5/thumbnails/5.jpg)
Pleistocene Connection
S. hispidus during LGM S. hispidus today
![Page 6: Conservation genetics of disjunct populations of Cotton Rat … · 2011-10-22 · Conservation genetics of disjunct populations of cotton rats (Sigmodon) along the Lower Colorado](https://reader033.vdocument.in/reader033/viewer/2022060312/5f0b2ccb7e708231d42f37c8/html5/thumbnails/6.jpg)
Recent Dispersal
Directional dispersal of S. arizonae through agricultural matrix to Bill Williams River
![Page 7: Conservation genetics of disjunct populations of Cotton Rat … · 2011-10-22 · Conservation genetics of disjunct populations of cotton rats (Sigmodon) along the Lower Colorado](https://reader033.vdocument.in/reader033/viewer/2022060312/5f0b2ccb7e708231d42f37c8/html5/thumbnails/7.jpg)
Between LCR and rest of species
• Pleistocene connection
– During cooler/wetter periods the two disjunct ranges were once continuous
• Expectations:– >18,000ybp– Some genetic
differentiation– Little to no dispersal
• Recent dispersal
– Recent agricultural practices may allow for connectivity
– “good years” may lead to population explosions
• Expectations:– <100ybp– No genetic differentiation– Some to considerable
dispersal
![Page 8: Conservation genetics of disjunct populations of Cotton Rat … · 2011-10-22 · Conservation genetics of disjunct populations of cotton rats (Sigmodon) along the Lower Colorado](https://reader033.vdocument.in/reader033/viewer/2022060312/5f0b2ccb7e708231d42f37c8/html5/thumbnails/8.jpg)
Materials and Methods
• Trapping– Known localities– Suitable habitat
• Goal – Maximize number of localities sampled– Up to 15 individuals per locality
• Museum samples
![Page 9: Conservation genetics of disjunct populations of Cotton Rat … · 2011-10-22 · Conservation genetics of disjunct populations of cotton rats (Sigmodon) along the Lower Colorado](https://reader033.vdocument.in/reader033/viewer/2022060312/5f0b2ccb7e708231d42f37c8/html5/thumbnails/9.jpg)
Materials and Methods
• Sequenced portion of control region– noncoding region of mitochondrial (mt)DNA
• Phylogenetic and Population genetic analyses– Phylogenetic trees– Haplotype Networks– AMOVA– Baysian relaxed molecular clock– Coalescent analyses
![Page 10: Conservation genetics of disjunct populations of Cotton Rat … · 2011-10-22 · Conservation genetics of disjunct populations of cotton rats (Sigmodon) along the Lower Colorado](https://reader033.vdocument.in/reader033/viewer/2022060312/5f0b2ccb7e708231d42f37c8/html5/thumbnails/10.jpg)
Results
• 19 localities sampled– 29 S. arizonae
• From 2 localities
– 18 S. hispidus• From 3 localities
![Page 11: Conservation genetics of disjunct populations of Cotton Rat … · 2011-10-22 · Conservation genetics of disjunct populations of cotton rats (Sigmodon) along the Lower Colorado](https://reader033.vdocument.in/reader033/viewer/2022060312/5f0b2ccb7e708231d42f37c8/html5/thumbnails/11.jpg)
Habitat• S. hispidus
– Phyragmites
![Page 12: Conservation genetics of disjunct populations of Cotton Rat … · 2011-10-22 · Conservation genetics of disjunct populations of cotton rats (Sigmodon) along the Lower Colorado](https://reader033.vdocument.in/reader033/viewer/2022060312/5f0b2ccb7e708231d42f37c8/html5/thumbnails/12.jpg)
Habitat
• Both species– Johnson grass
![Page 13: Conservation genetics of disjunct populations of Cotton Rat … · 2011-10-22 · Conservation genetics of disjunct populations of cotton rats (Sigmodon) along the Lower Colorado](https://reader033.vdocument.in/reader033/viewer/2022060312/5f0b2ccb7e708231d42f37c8/html5/thumbnails/13.jpg)
• S. arizonae– Natural?
Habitat
![Page 14: Conservation genetics of disjunct populations of Cotton Rat … · 2011-10-22 · Conservation genetics of disjunct populations of cotton rats (Sigmodon) along the Lower Colorado](https://reader033.vdocument.in/reader033/viewer/2022060312/5f0b2ccb7e708231d42f37c8/html5/thumbnails/14.jpg)
![Page 15: Conservation genetics of disjunct populations of Cotton Rat … · 2011-10-22 · Conservation genetics of disjunct populations of cotton rats (Sigmodon) along the Lower Colorado](https://reader033.vdocument.in/reader033/viewer/2022060312/5f0b2ccb7e708231d42f37c8/html5/thumbnails/15.jpg)
Sequencing Results
• 54 individuals– sequenced so far
• 7 haplotypes– 3 S. hispidus– 4 S. arizonae
![Page 16: Conservation genetics of disjunct populations of Cotton Rat … · 2011-10-22 · Conservation genetics of disjunct populations of cotton rats (Sigmodon) along the Lower Colorado](https://reader033.vdocument.in/reader033/viewer/2022060312/5f0b2ccb7e708231d42f37c8/html5/thumbnails/16.jpg)
Sequencing Results
0.01
Sigmodon arizonae Sigmodon hispidus
LCR LCRCA AZ AZ / CA
![Page 17: Conservation genetics of disjunct populations of Cotton Rat … · 2011-10-22 · Conservation genetics of disjunct populations of cotton rats (Sigmodon) along the Lower Colorado](https://reader033.vdocument.in/reader033/viewer/2022060312/5f0b2ccb7e708231d42f37c8/html5/thumbnails/17.jpg)
Discussion
• LCR Populations– Fixed for unique haplotypes
• Low variability– Each locality = single haplotype– Likely due to small founder populations– Natural history
• Compares to previous study
![Page 18: Conservation genetics of disjunct populations of Cotton Rat … · 2011-10-22 · Conservation genetics of disjunct populations of cotton rats (Sigmodon) along the Lower Colorado](https://reader033.vdocument.in/reader033/viewer/2022060312/5f0b2ccb7e708231d42f37c8/html5/thumbnails/18.jpg)
Discussion
• What does this mean for conservation efforts?– Support sub-specific status of populations
• Recent divergence
– If habitat is available they appear to be good at colonizing
– Reintroduction efforts might not be necessary• CA vs AZ for S. arizonae
![Page 19: Conservation genetics of disjunct populations of Cotton Rat … · 2011-10-22 · Conservation genetics of disjunct populations of cotton rats (Sigmodon) along the Lower Colorado](https://reader033.vdocument.in/reader033/viewer/2022060312/5f0b2ccb7e708231d42f37c8/html5/thumbnails/19.jpg)