neurogenesis Flashcards
site of mammalian neurogenesis
apical surface of neural tube
cell cycle S phase
synthesis of DNA
symmetric divisions
early embryogenesis to proliferate a lot of progenitors -> create a big pool
asymmetric division
two different daughter cells
to terminate progenitor production
songbirds
evidence for adult neurogenesis in NSC
quiescence
Key feature of neurogenesis
Can exit cycle and stay in G0
Minimises cell damage
Ensures pool isn’t fully depleted
We don’t know how to activate them
Smaller
fruit fly - embryonic neurogenesis 3 steps
Activate proneural genes
Lateral inhibition via NOTCH signalling
Delamination of neuroblasts followed by asymmetric division
delta & notch
delta - ligand
notch - receptor
lateral inhibition via notch
Delta binds to notch which activates SuH which induced E(spl) turning off ASC = no delta formation = can’t activate neuronal
overexpression of notch
all ectoderm
no notch
all neuroblasts
pros
shuts off proliferative nature
converts NB to ganglia mother cell (for differentiation)
miranda
tethers pros to the cortex
what happens when pros, brat, mira are mutated?
can’t localise (switch off proliferative)
continues to behave like stem cell
overgrowth of NB
tumour
(however this wont happen in embryos)
ectopic stem cells are ______ proliferative
HIGHLY proliferative
DamID
used to identify target genes of Pros
see where the markers bind
nerfin 1
Keeps cell in stem cell state
Upregulated in children’s tumours
When inject nerfin-1: size similar to neurons (are we reverting back)
Nerfin-1 injection -> edu+ -> neural stem cells
mlnsc and asg3 (pins) important for ??
asymmetric division
type I vs type II NB (fruit fly)
type 1 not rapid
type 2 produces 6 neurons therefore more rapid
end of neurogenesis - fruit fly
Terminal symmetric division
At very end of cycle
Smaller NSC = no longer a NSC
overexpress pros before proliferation
Or, switch off glycolysis (which usually gives replenishment energy)
how do we know nutrients are necessary to reactive NB?
didnt happen in starved
nutritional signals
Necessary for replenishment
Signals activate PI3K signalling to trigger cell cycle entry for NB (throug insulin like peptides)
what transcription factor when young
red, hb
