Limb Development Flashcards
Where is the initial outgrowth induced from?
Flank mesoderm
What transcription factors do the target genes include?
Tbx 4
Tbx 5
Brachyury
What is the Tbx 5 mutation in humans associated with?
Holt-Oram syndrome
What is the important signalling centre that is ectoderm derived called?
The Apical Ectoderma Ridge
How is P-D (proximal-distal) identity specified?
Time spent in the progress zone
What promotes cell division?
FGF
What is the two-signal model?
Opposing gradients of FGF-RA pattern the axis
What does high FGF and high RA mean?
FGF- distal
RA- proximal
What is the function of FGF?
Promotes differentiation
Inhibits Raldh2
What is the function of RA?
Promotes differentiation
Inhibits Fgf8 transcription
Promotes Fgf8 transcript degradation
Where is the polarising region located?
Posterior
What is the polarising region a source of?
Sonic Hedgehog signals
