Lecture 13: Nervous System Induction Flashcards
Cerebrus-like and DKK-1
Origin: anterior visceral endoderm
Role: inhibits development of posterior structures and thus establishes the A/P axis
What are the effects of Foxa-2 in the early primitive streak stage?
Establishes primitive node, initiates notochord function, establishes midline structures from cranial end to node
What signaling molecule is necessary for normal head formation in late primitive streak stage?
Cerebrus-related 1
What signaling molecules released from primitive streak activate Hox genes in the late primitive streak stage?
Retinoic acid, Wnt, FGF
Determination
Process by which cell/part of embryo becomes restricted to a given developmental pathway (committed to a specific cell line)
Differentiation
Complex of changes involved in progressive specialization of structure and function, often resulting information of luxury molecules
What is the 1st sign of asymmetry in early development?
Asymmetrical beating of cilia around primitive node resulting in directional current and expression of TGF-B molecules
What is the role of Nodal with respect to L/R asymmetry?
Nodal is swept to the left side of the embryo by the ciliary current; stimulates multiple gene expression pathways via Pitx2
What is the role of Lefty-1 with respect to L/R asymmetry?
Lefty-1 is expressed on the left side of the embryo and blocks diffusion of genetic material to the right side