Development of the RPE layer is coordinated with the early development
of the retina via the anterior neural plate, but RPE development branches
from the neural retina during optic vesicle formation. In mice, a distinct RPEfated
cell layer is identified on E9.5; prior to this time those cells destined to
become the RPE are comingled with those cells destined to become the
neural retina (Martinez-Morales et al. 2004). As the RPE layre develops,
224 William L’Amoreaux
certain transcriptional regulators are expressed in the RPE progenitor cells,
including Otx, Pax6, and Mitf, especially the products of Mitf-A, -H, and -D
(Martinez-Morales et al. 2004). With the putative role of taurine established
in the development of the neural retina, nothing is yet known as to the
expression of taurine, the taurine transporter (TauT), or targets of taurine in
the developing RPE layer