lecture 2- establishing vertebrate nervous system Flashcards
how in signal transduction involved neural cell formation
it leads to transcription factors changing gene expression
what is the key pathway in establishing the nervous system
BMP
describe the BMP pathway
BMP released
binds to receptors which cause signal cascade
smad proteins then activated which act as TFs
what are the antagonists for the BMP pathway and how do they work
Chordin and noggin
they drown out the signal of BMP
where do organiser cells form
dorsal side of the mesoderm
what do ectodermal cells on the dorsal side of the cell form
neural tissus
what do ectodermal cells on the ventral side of the cell form
epidermal tissue
how do the organisor cells induce cell fate
they express antagonists of BMP signalling
so BMP pathway not triggered
so neural cells form around them
What pathway occurs when the BMP pathway isnt activated
sox transcription factors activated
neural tissue formed
what is neural induction
setting aside of part of the ectoderm to be neural plate cells
discuss the gain of function experiment to find out what organiser cells achieve
chop out organiser cells from white newt donor and add them to ventral mesoderm of the black host
result is that 2 CNS arose, both black
what are the 2 conclusions that can be derived from the newt gain of function experiment
1- colour of CNSs tells us that host cells have been induced by external factors coming from the organiser
2- organiser itself comes up with a completely different tissue in a different part of the embryo
how did scientists know BMP antagonists were responsible for inducing neural tissue
they took organiser mRNA , turned it into cDNA then added it ectopically
then they used trial and error to find which mRNA codes for neural cells
they found these were all BMP antagonists
