Cell Fate and Embryonic Induction Flashcards Preview

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Flashcards in Cell Fate and Embryonic Induction Deck (25)
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1

Difference between preformation and epigenesis

Correctly position in fertilised egg / added progressively during development

2

Cleavage divisions in ascidians

Holoblastic

3

Yellow cytoplasm of ascidian always found in

Muscle cells of the larval tail

4

macho-1

A putative zinc-finger TF, sufficient and necessary for primary muscle formation

5

Maternal macho-1 is localised in _______ cytoplasm at ___ and ____ cell stage

in yellow cytoplasm at 16 and 32 cell stage

6

Embryonic regulation

Ability of embryo to develop normally when portions are removed or rearranged

7

Embryonic induction

Process whereby cell-cell signalling affects development of responding cells

8

Competence

Ability of cell/tissue to respond to an inductive signal

9

Mesoderm is induced in the ______ fragment by the ______ fragment

animal, vegetal

10

Which proteins are good candidates for mesoderm-inducing signal?

Nodal and GDF3 in TGFb families

11

Xenopus Nodal RNA is localised to _______ hemisphere of _______

Localised to vegetal hemisphere of blastula

12

Inhibition of nodal signalling

Blocks mesoderm formation

13

Nodal induces expression of

TF brachyury and several members of the FGF family

14

STK

Serine/thereonine kinase in cytoplasmic kinase domain of c.s. receptor for TGFb ligand

15

Tyrosine kinase is in the ______ domain of ____ receptor for ____ ligand

In cytoplasmic kinase domain of c.s. receptor for FGF ligand

16

TGFb ligand becomes ______ that binds to extracellular domain of ________

Dimer, type 1 and type 2 receptors

17

Activated type 1 receptors

Phosphorylate smad2

18

Smad 2: Smad 4 complex

Migrates into nucleus where it interacts with co-transcription factors and binds to cis-regulatory elements

19

Why is nodal signalling an auto-regulatory loop?

TGFb + FGF signals positively regulate transcription of brachyury which encodes a T-box transcription that positive regulates fgf4 and fgf8

20

At early stages, neural tube at ventral half divides into:

1. Floor plate cells at ventral midline above notochord
2. Motor neurones
3. Interneurons

21

Shh is both sufficient and necessary for formation of

Ventral neural tube sub-types

22

From low to high concentration of Shh

V0, V1, V2, Motor Neurons, V3 and finally floor plate

23

Shh is a _____, ____ secreted from _____ plate

morphogen -> BMP secreted from roof plate

24

Shh -> mesodermal cell type

Sclerotome

25

Nodal induces _______ when added to _______ caps

Mesoderm, animal