Early Development Lec02 Flashcards
Gastrulation defines the ___, ___, and ___ axes of the nembryo
midline, anterior-posterior and dorsal-ventral
the midline of the embryo is defined by the formation of the ____
notocord
notocord is formation incudes the formation of the ____
neural ectoderm
____ formationn is the ver y first event in neurogenesis
otochord formation
___ are the neural rpecurosr cells, which turns into CNS
neural ectoderm
if you treat ectoderm with ___ you get epidermis
bmp (a transforming growth factor beta)
if you treat ectoderm with ___ you get NEUROECTODERM
noggin chordin (inhibit BMP)
BMPs are made by the ____
surrounding tissue
Factors that inhibit BMP signaling are produced by the ____ (
notochord
___ signaling precedes BMP inhibition during neural induction
FGF
what do noggin and chordin do?
block bmp (thus, inducing neural development)
FGF stimulation increases production of ____
Noggin
neural induction the lateral margins of the____ fold inward to form the \n\nneural tube
neural plate
neural tube forms around day ___
20
the____ pinches off when the NEURAL TUBE is formed
neural crest
Neural tube closes from the middle both____ and ___
anteriorly and posteriorly (like a zipper going in both directions)
____ vitamins in the first few weeks of \n\npregnancy decrease neural tube closure defects.
B-complex (folic acid)
Spina Bifida rate in US is much lower since ____
nutrition
Spina Bifida is the failure of the ____ end of the neural tube to close
posterior
Anencephaly and holoprosenchephaly (Represents failure of the ___ neural tube to close.
anterior
Anencephaly and holoprosenchephaly lack ___
forebrain
____ makes cells in one area different from cells in another area
patterning
ventral patterning is realted to ___ function
motor
ventral siganl is secreted ____
sonic hedgehog
dorsal siganl is secreted ____
tgf betas
sonic hedgehog eventually leads to differences in ____
trnascription
What produces dorsal ventral polarity?
high sonic hedgehog in notocord and roof plate
no sonic headhog in the roof plate
roteins encoded by hox genes are powerful ____
transcriptional activators and repressors
results from abscence of sonic hedgehog:
- The forebrain does not form
- dorsal ventral polarity is disrupted