Question

Which transcription factor plays an important role in determining the ipsilateral tract of the retinal neurons at the optic chiasm? For mice that lack the transcription factor, how is the ipsilateral tract affected?

Answer 1

Transcription factors Math5 and Sox2 are expressed in the ipsilateral tract in retinal progenitor cells.

Sox2 expression is observed in proliferative regions of the retina like neuroblastic layer progenitors, ciliary body progenitors, and optic nerve head glial progenitors. Sox2 expression is down-regulated during the final division when the progenitor becomes postmitotic.

Math5 is expressed in retinal progenitor cells after they acquire competence to form retinal ganglion cells (RGCs). It marks the first neurogenic competence state of retinal progenitors.

A complete absence of these factors leads to loss of neuronal progenitors while reduced expression leads to maturation defects of RGCs. The othercell types are not affected.