Lecture 7 - Establishment of the Dorso-Ventral axis Flashcards
How does the embryo break symmetry?
Via asymmetrical mitosis
How does the Zenopus egg show its distinct polarity?
- Animal pole is pigmented
- Vegetal pole contains the yolk
Where is coco expressed?
- Animal pole
- Equatorial region
Where is vg1 expressed?
- Equatorial region
- Vegetal pole
What does coco do?
Inhibits TGF-beta signalling
What is vg1?
A TGF-beta family member
What process is bg1 required for?
Mesoderm induction during development
How is the dorsal ventral axis set up in the oocyte?
The point of sperm entry dictates the ventral side of the oocyte
What is the Nieuwkoop Centre?
A signalling centre that defines the dorsal side of the oocyte
What is the role of the Nieuwkoop centre?
To influence the development of surrounding cells
What happens when you divide the embryo along the dorsal/ventral axis?
- Dorsal side develops into dorsalised embryo
- Ventral side develops into ventralised embryo
What happens when you graft the dorsal blastomere on the ventral side?
The embryo forms two dorsal sides with two heads
What happens when you use UV light to disrupt the formation of the Niewkoop centre?
A decrease of dorsal and anterior structures
What is important about Canonical Wnt signalling?
It is essential for the molecular activity defining the Niewkoop centre
