Diff6 - 17 Flashcards
Where do the neural inducing and dorsalisation properties of the organiser come from?
Its ability to synthesise and secrete various unique products
What does the organiser secrete?
BMP-inhibitors
Examples of BMP inihibitors
Chordin, noggin, follistatin
Outline modal dorsalisation of mesoderm
Low level nodal gives ventral mesoderm, high level nodal gives organiser, signals from organiser act to inhibit BMP signal from ventral mesoderm to dorsalise the organiser side
Draw the modal dorsalisation of mesoderm
1: Low level Nodal = ventral mesoderm
2: High level Nodal = organiser
3: BMP inhibitors dorsalise mesoderm
4: BMP agonists ventralise mesoderm
What does BMP stand for?
Bone morphogenetic proteins
Outline neural induction
All ectodermal cells synthesise BMPs, acting locally on TGF-beta, and if activated will differentiate into epidermal ectoderm; chordin/noggin competes for binding and if not activated, they will become neural
Ventral to dorsal, what does the mesoderm derive into?
Blood, kidney, somites, heart, notochord
Draw the fate map of the xenopus embryo
When was the organiser graft experiment conducted?
1920
Who conducted the organiser graft experiment?
Spemann and Mangold
What was the organiser graft experiment?
Grafted an organiser from donor to host newt - found that a twinned embryo developed
What was important about the organiser graft experiment?
Secondary axis was host deriven - showed the neural tissue was induced from the ectoderm
Summarise post-gastrulation layout
What is expressed post-gastrulation?
SHh
