BIOL 3010 Lecture Notes - Lecture 13: Repressor, T-Box, Zone Of Polarizing Activity

• School: University of Guelph
• Department: Biology
• Course: BIOL 3010
• Professor: Scott Schau

Document Summary

Limb development: embryologic origin of the limb development. Limb bud appears at 4 weeks and is complete at 8 weeks; limbs rotate during. Source of limb components (mostly what you d expect) Lateral plate mesoderm: bones, tendons, ligaments, dermis, vasculature. Edge of bud is apical ectodermal ridge (aer), critical for limb formation. Within limb bud is progress zone (high proliferation) and mesenchymal mesoderm (stop dividing, differentiate into proper proximal/distal fate) Limb axes are unusual: anterior (thumb), dorsal (back of hand), distal (fingers) Fgf expression by the aer controls where the limb forms along the a/p axis of. How the limb is patterned the body: proximal/distal axis. The hox-d genes are differentially expressed along the p/d axis. Fgfs stimulate bud outgrowth while bmp2 inhibits it: a/p axis. The zone of polarizing activity (zpa) in the posterior limb bud is responsible for a/p limb patterning. The zpa produces shh which acts as a morphogen.