The transcription factor NeuroD1 is known to play a role in photoreceptor development, but its precise role in genesis, specification, and/or maintenance is not clear. Liu et al.
now report that NeuroD1 helps to specify medium-wavelength M-opsin cone photoreceptors by activating the thyroid hormone receptor TRβ2 via an intron control region. Like TRβ2 knock-outs, NeuroD1–/– knock-out mice had as many cones as wild type, but all the cones expressed short-wavelength S-opsin, and none expressed M-opsin. TRβ2 expression was reduced 10-fold in NeuroD1–/– mice but was restored by transfecting the mutant retinas with NeuroD1. Furthermore, mutation of a sequence in the intron control region prevented induction of TRβ2 by NeuroD1. Both the roles of NeuroD1 and the regulation of opsin expression are more complicated than described here, however. NeuroD1 by itself cannot induce TRβ2 (and thus M-opsin) expression, and photoreceptor degeneration occurs in NeuroD1, but not TRβ2 knock-outs.-Society for Neuroscience
Comment and add to the story without registration, but keep the comments meaningful please. Links are not accepted.
