Lecture 11- Cell Death in Development Flashcards
(16 cards)
pathological cell death
triggered by external factors such as oxidative stress, involves cell rupture and inflammatory response
programmed cell death
developmental process, cell shrinkage/DNA concentration/cell fragmentation, phagocytosis of fragments
general name for proteins controlling apoptosis
caspases
2 types of caspase
initiator and executioner
initiator caspase mechanism of action
form a dimer
autoproteolytic cleavage, which creates the active form
what do initiator caspases do
activate executioner caspases
executioner caspase mechanism of activation
also forms a domer, cleavage by initiator caspases to make active form
how are mitochondria involved in apoptosis
BCL2 mitochondrial membrane proteins regulate initiator caspase activity- usually inhibits apoptosis
what can trigger initiator caspases
reactive oxygen species/cytochrome C leaking from the mitochondria
examples of caspase-independent cell death
linker cell-type death, may occur in vertebrate sex determination to the bipotential gonad cell
autophagy, doesn’t normally cause cell death though
3 techniques for studying cell death
DNA staining e.g. DAPI- can see fragmented genetic material
live/dead staining using a marker which usually can’t cross cell membranes but can during apoptosis
anti-caspase antibodies in already dead tissue
example of where cell death might occur
making a vertebrate hand, cell death between digits
what is the system which promotes apoptosis between digits
Msx/BMP
how do webbed appendages form
repression of the system which usually causes inter-digit cell death
another system which has a lot of cell death
insect nervous system- whole hemilineages can be killed
example of an insect cell lineage killed during development
flight control hemilineage in swift louseflies
