Evolution of Multicellularity Flashcards
What residues are usually phosphorylated during cell signalling?
serine, threonine or tyrosine
What protein is associated with evolution of multicellularity due to the difference in abundance between multicellular and unicellular organisms?
kinases eg receptor tyrosine kinases (RTK) and cytoplasmic tyrosine kinases (CTK)
What protein is found in choanoflagellates used for bacteria capture and later co-opted for cell-cell adhesion?
cadherins
How is the Wnt signalling pathway inhibited in the absence of Wnt in sponges?
GSK3β phosphorylates β-catenin which causes it to be constantly degraded meaning no response can be initiated
How does he Wnt signalling pathway occur in the presence of Wnt in sponges?
GSK3β is pulled to the cell membrane so it can no longer interact with β-catenin
this allows β-catenin to translocate the nucleus where it binds the TCF TF and Wnt responsive genes are turned on
What biological kingdom is Wnt signalling found in?
animal
Where is Wnt expression usually found in bilateral animals?
the tail, decreasing in concentration as it moves towards the head and corresponding Wnt inhibitors are found at high concentrations in the head, decreasing as they move towards the tail
What is the most ancient type of sensory-to-motor transformation?
ciliary motion
What are the sensor cells found in called in sponges?
flask cells
How is it hypothesised that nerve cells evolved from sponges to ctenophora?
as they evolved the flask cells were able to interact with more and more cells, probably becoming axon-like structures
The change in activity of phosphorylated Src in animals but not choanoflagellates (which also have Src, but phosphorylation doesn’t deactivate it) shows what?
An increase in kinase regulation in animals but compared to single felled organisms (important for cell-cell signalling)
