evolution of apoptosis by sean a. mcmillan. what is apoptosis? programmed cell death (pcd) several...
TRANSCRIPT
![Page 1: Evolution of Apoptosis By Sean A. McMillan. What is Apoptosis? Programmed cell death (PCD) Several kinds – Caspase dependent – Caspase independent Ex:](https://reader030.vdocument.in/reader030/viewer/2022032605/56649e7b5503460f94b7ceec/html5/thumbnails/1.jpg)
Evolution of Apoptosis
By Sean A. McMillan
![Page 2: Evolution of Apoptosis By Sean A. McMillan. What is Apoptosis? Programmed cell death (PCD) Several kinds – Caspase dependent – Caspase independent Ex:](https://reader030.vdocument.in/reader030/viewer/2022032605/56649e7b5503460f94b7ceec/html5/thumbnails/2.jpg)
What is Apoptosis?
• Programmed cell death (PCD)• Several kinds
– Caspase dependent– Caspase independent
• Ex: high amounts of Ca+ can initiate apoptosis
• Caspases are proteases that play key roles in apoptosis
• Was believed to be only a multicellular trait
![Page 3: Evolution of Apoptosis By Sean A. McMillan. What is Apoptosis? Programmed cell death (PCD) Several kinds – Caspase dependent – Caspase independent Ex:](https://reader030.vdocument.in/reader030/viewer/2022032605/56649e7b5503460f94b7ceec/html5/thumbnails/3.jpg)
Purpose of apoptosis
• Mitosis checkpoints• Apoptosis will be
triggered to prevent cells from becoming cancers and harming the body
![Page 4: Evolution of Apoptosis By Sean A. McMillan. What is Apoptosis? Programmed cell death (PCD) Several kinds – Caspase dependent – Caspase independent Ex:](https://reader030.vdocument.in/reader030/viewer/2022032605/56649e7b5503460f94b7ceec/html5/thumbnails/4.jpg)
Purpose continued
• Apoptosis purpose is to prevent a defective cell from multiplying and creating more cells with its implication
![Page 5: Evolution of Apoptosis By Sean A. McMillan. What is Apoptosis? Programmed cell death (PCD) Several kinds – Caspase dependent – Caspase independent Ex:](https://reader030.vdocument.in/reader030/viewer/2022032605/56649e7b5503460f94b7ceec/html5/thumbnails/5.jpg)
What is Apoptosis?
• Programmed cell death (PCD)• Several kinds
– Caspase dependent– Caspase independent
• Ex: high amounts of Ca+ can initiate apoptosis
• Caspases are proteases that play key roles in apoptosis
• Was believed to be only a multicellular trait
![Page 6: Evolution of Apoptosis By Sean A. McMillan. What is Apoptosis? Programmed cell death (PCD) Several kinds – Caspase dependent – Caspase independent Ex:](https://reader030.vdocument.in/reader030/viewer/2022032605/56649e7b5503460f94b7ceec/html5/thumbnails/6.jpg)
evolution
• Maria segovia et al. • Did research into apoptosis in higher
metazoans and in unicellular organism Dunaliella tertiolecta
• 5 day experiment • Observed Dunaliella tertiolecta in a light
deprived state
![Page 7: Evolution of Apoptosis By Sean A. McMillan. What is Apoptosis? Programmed cell death (PCD) Several kinds – Caspase dependent – Caspase independent Ex:](https://reader030.vdocument.in/reader030/viewer/2022032605/56649e7b5503460f94b7ceec/html5/thumbnails/7.jpg)
Dunaliella tertiolecta
• Unicellular organism that derives its energy through light
• Segovia set up an experiment to see if in the absence of light Dunaliella tertiolecta experienced apoptosis
![Page 8: Evolution of Apoptosis By Sean A. McMillan. What is Apoptosis? Programmed cell death (PCD) Several kinds – Caspase dependent – Caspase independent Ex:](https://reader030.vdocument.in/reader030/viewer/2022032605/56649e7b5503460f94b7ceec/html5/thumbnails/8.jpg)
Results
• At the end of the 5 day period Dunaliella tertiolecta had lost all color
• Chromatin condensation
• Nuclear membrane degradation
• DNA fragmention
![Page 9: Evolution of Apoptosis By Sean A. McMillan. What is Apoptosis? Programmed cell death (PCD) Several kinds – Caspase dependent – Caspase independent Ex:](https://reader030.vdocument.in/reader030/viewer/2022032605/56649e7b5503460f94b7ceec/html5/thumbnails/9.jpg)
Results
• Dunaliella tertiolecta did in fact show signs of apoptosis
![Page 10: Evolution of Apoptosis By Sean A. McMillan. What is Apoptosis? Programmed cell death (PCD) Several kinds – Caspase dependent – Caspase independent Ex:](https://reader030.vdocument.in/reader030/viewer/2022032605/56649e7b5503460f94b7ceec/html5/thumbnails/10.jpg)
Western blot
• Ran the extracts of Dunaliella tertiolecta whole proteins with antibodys to human caspases
• Caspases are very specific proteases
![Page 11: Evolution of Apoptosis By Sean A. McMillan. What is Apoptosis? Programmed cell death (PCD) Several kinds – Caspase dependent – Caspase independent Ex:](https://reader030.vdocument.in/reader030/viewer/2022032605/56649e7b5503460f94b7ceec/html5/thumbnails/11.jpg)
discussion
• Family of caspases predates multicellur organisms.
• Viral infection from unicellular organisms could have transferred both machinery and pathway into eukaryotes
![Page 12: Evolution of Apoptosis By Sean A. McMillan. What is Apoptosis? Programmed cell death (PCD) Several kinds – Caspase dependent – Caspase independent Ex:](https://reader030.vdocument.in/reader030/viewer/2022032605/56649e7b5503460f94b7ceec/html5/thumbnails/12.jpg)
Apoptosis
• Frank medeo• Also found evidence of caspase like activity in
unicellar organisms• yeast
![Page 13: Evolution of Apoptosis By Sean A. McMillan. What is Apoptosis? Programmed cell death (PCD) Several kinds – Caspase dependent – Caspase independent Ex:](https://reader030.vdocument.in/reader030/viewer/2022032605/56649e7b5503460f94b7ceec/html5/thumbnails/13.jpg)
Further research
• More research into mechanisms and machinery
• Better understanding could help treat cancer• Clearer understanding of human evolution
![Page 14: Evolution of Apoptosis By Sean A. McMillan. What is Apoptosis? Programmed cell death (PCD) Several kinds – Caspase dependent – Caspase independent Ex:](https://reader030.vdocument.in/reader030/viewer/2022032605/56649e7b5503460f94b7ceec/html5/thumbnails/14.jpg)
Works Cited• Maria Segovia, Liti Haramaty, John A. Berges, and Paul G. Falkowski. 2003
Plant Physiology. Cell Death in the Unicellular Chlorophyte Dunaliella tertiolecta. A Hypothesis on the Evolution of Apoptosis in Higher Plants and Metazoans, plant physiology. Volume 32,Pg. 99-105
• Madeo F, Herker E, Maldener C, Wissing S, La¨chelt S, Herlan M, Fehr M,Lauber K, Sigrist SJ, Wesselborg S et al. (2002) A caspases-related protease regulates apoptosis in yeast. Mol Cell 9: 911–917