Requirement for math5 in the development of retinal ganglion cells

Abstract

math5 is a murine orthologue of atonal, a bHLH proneural gene essential for the formation of photoreceptors and chordotonal organs in Drosophila. The expression ofmath5 coincides with the onset of retinal ganglion cell (RGC) differentiation. Targeted deletion of math5 blocks the initial differentiation of 80% of RGCs and results in an increase in differentiated amacrine cells. Furthermore, the absence ofmath5 abolishes the retinal expression of brn-3b and the formation of virtually all brn-3b-expressing RGCs. These results imply that math5 is a proneural gene essential for RGC differentiation and that math5 acts upstream to activatebrn-3b-dependent differentiation processes in RGCs.