L12 Flashcards
ectoderm has high _____, and ventral + mesoderm has high _____ and _____
BMP
BMP
wnt
gastrulation can be described as coordinated cell movements to _______ the blastula into a __________ structure
re-organize
trilaminar
gastrulation is initiated by the formation of __________
bottle cells
bottle cells form at the border of _______ and _______, and on the _____ side of the embryo
mesoderm
endoderm
dorsal
what are the four tissue movements during xenopus gastrulation?
______ of the superficial layer of the ectoderm
_______ of the deep layer of the ectoderm
________ rolling in of endoderm and mesoderm
_________ of the mesoderm (elongation of the AP axis)
epiboly
radial intercalation
involution
convergent extension
in involution of the mesoderm, the animal pole epithelium _________, and mesodermal cells migrate over _________. then, bottle cells help force ___________ of invaginating epithelium
expands
fibronectin
curvature
the fibronectin in involution is secreted by the cells from the _________ roof, and forms an ________ matrix. the mesodermic cells then express ________ that bind to FN
blastocoel
extracellular
integrins
the three steps in convergence-extension of the mesoderm are what
contraction of the cell + protrusion
pulling of the cell towards the midline
cell intercalation
the first cells to invaginate from the epiblast through the primitive streak displace the cells from the ______, and form the ___________
hypoblast
definitive endoderm
(so basically first cells to invaginate become the endoderm)
mesoderm cells ________ through primitive streak
ingress
how does one signal elicit different responses?
differential expression of intracellular regulators
_______ use of different signalling pathways also increase the response diversity
combinatorial