Lec 27: Early Embryonic Patterning

Question 1

What is the source and role of Nodal?

Answer 1

Source: embryonic node and lateral mesoderm
Role: stimulates Pitx2 expression, leading to LR asymmetry

Question 2

What is the source and role of Pitx2?

Answer 2

Source: lateral mesoderm
Role: downstream of Nodal, regulates development of LR asymmetry of organs

Question 3

What is the source and role of BMPs?

Answer 3

Source: epiblast
Role: promote epidermal fate

Question 4

What is the source and role of noggin and chordin? What are they antagonists of?

Answer 4

Antagonists of BMP
Source: node and notochord
Role: promote neural fate

Question 5

What is the source and role of FGFs, Wnts, and RA?

Answer 5

Source: posterior mesoderm
Role: promote posterior fate

Question 6

What is the source and role of Dickkopf (+Noggin and Chordin)

Answer 6

Source: anterior mesoderm and endoderm, AVE (Anterior visceral endoderm)
Role: promotes cranial (anterior) neural fate

Question 7

What is the source and role of Hox?

Answer 7

Source: neural tube, somites, gut, urogenital organs, limb
Role: Encode regional identity

Question 8

What is the source and role of RA and FGFs?

Answer 8

Source: Mesoderm and node
Role: RA (and FGFs) program Hox in the CNS