[Intracellular localization of transcription factor PROX1 in the human retina in ontogeny]

The spatiotemporal intracellular localization of the transcription factor PROX1 in the human retina during prenatal development (fetal weeks 9.5 to 31) and in the adult human retina was studied for the first time. The PROX1 protein was identified in the cell nuclei of the neuroblast retinal layers at the stage of active cell proliferation (fetal week 9.5) as well as in the nuclei of differentiating neurons of the inner nuclear retinal layer (horizontal, amacrine, and bipolar cells) from weeks 13 to 31 of prenatal development. The PROX1 protein localization in the adult retina was the same as at the late stage of prenatal development. Our results indicate the involvement of the transcription factor PROX1 in the regulation of proliferation of progenitor cells and differentiation of the inner nuclear layer cells of the human retina. These results confirm the conservative functions of Prox1/PROX1 in the vertebrate retina.