Biology 1002B Lecture Notes - Lecture 16: Blastoderm, Pupa, Multinucleate

• School: Western University
• Department: Biology
• Course: Biology 1002B
• Professor: Tom Haffie Denis Maxwell

Document Summary

Thecaspase-9 gene, which encodes a protease that degrades cell structures, is activated in cells that form the webbing between the fingers and toes in a human embryo, causing it to break down. Mammalian cells are saved from death by the bcl family of genes, which are the equivalent of ced-9 in c. elegans. The genes are so closely related that they retain their effects if they are exchanged betweenc. elegans and human cells: programmed cell death cascade in c. elegans. In c. elegans, a death signal molecule that binds to a receptor in the plasma membrane of the target cell results in apoptosis. When the receptor is activated, it leads to activation of proteins that kill the cell. The killing proteins remain inactive in the absence of the death signal. When a death signal binds to and activates a receptor, the resulting events are typical of signal transduction pathways. Now the activated receptor leads to inactivation of ced-9.