Biochemistry 3381A Study Guide - Quiz Guide: Sonic Hedgehog, Mexican Tetra, Optic Vesicle

• School: Western University
• Department: Biochemistry
• Course: Biochemistry 3381A
• Professor: Brian Shilton

Document Summary

The optic vesicle is formed as a protrusion of the diencephalon. Where it gets in contact with the epidermis, the latter thickens and forms the lens placode. The lens placode invaginates to form the lens. The optic vesicle invaginates to form the optic cup. The outer layer of the optic cup forms a pigmented epithelium. In the anterior neural tube noggin promotes otx 2 expression and inhibits et. The inner layer of the optic cup differentiates into the neural retina. First step: formation of the eye field in the neutral plate. Otx 2 accumulates, noggin is blocked and et gets expressed. Et activates rx1 which promotes pax6 expression. Pax6 initiates a cascade that constitute the eye field. To form two optic vesicles out of one eye field, pax6 expression in the center of the field is inhibited. Sonic hedgehog is secreted by the prechordal plate and inhibits pax6 in the middle eye field.