140 likes | 373 Views
Evolution of Apoptosis. By Sean A. McMillan. 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
E N D
Evolution of Apoptosis By Sean A. McMillan
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
Purpose of apoptosis • Mitosis checkpoints • Apoptosis will be triggered to prevent cells from becoming cancers and harming the body
Purpose continued • Apoptosis purpose is to prevent a defective cell from multiplying and creating more cells with its implication
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
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
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
Results • At the end of the 5 day period Dunaliella tertiolecta had lost all color • Chromatin condensation • Nuclear membrane degradation • DNA fragmention
Results • Dunaliella tertiolecta did in fact show signs of apoptosis
Western blot • Ran the extracts of Dunaliella tertiolecta whole proteins with antibodys to human caspases • Caspases are very specific proteases
discussion • Family of caspases predates multicellur organisms. • Viral infection from unicellular organisms could have transferred both machinery and pathway into eukaryotes
Apoptosis • Frank medeo • Also found evidence of caspase like activity in unicellar organisms • yeast
Further research • More research into mechanisms and machinery • Better understanding could help treat cancer • Clearer understanding of human evolution
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