BIOL303 Lecture Notes - Neural Crest, Adrenal Medulla, Sox9
19 Dec 2013
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Document Summary
The neural crest is derived from the ectoderm. It is often considered as the fourth germ layer, a transient structure that can undergo epithelial to mesenchyme transition and become migratory. Their specification is determined by neural plate inductive signals bmp and wnts. If wnt turns on bmps and wnt stays on, the neural crest is established: foxd3, snail, twist, and sox9 are examples of neural crest specifier genes. Events such as epithelial-to-mesenchyme transition and delamination are associated with the expression of these genes. Without sox9, the cells will undergo apoptosis when they delaminate: there are four general regional fates of neural crest cells according to their position of origin along the anterior/posterior axis. Cranial: cartilage and bones, neurons and glia in face, thymic cells, odontoblasts/teeth, middle ear bones and jaw. Cardiac: melanocytes, neurons cartilage, connective tissue, musculature and connective tissue of large as arteries and heart septum.
