The expression pattern of heterogeneous nuclear ribonucleoprotein R in rat retina.

The heterogeneous nuclear ribonucleoproteins (hnRNPs) play important roles in DNA repairing, cell signaling, telomere biogenesis, and in regulating gene expression at both transcriptional and translational levels. In the present study, we demonstrated that the expression of hnRNP-R1 and hnRNP-R2 is developmentally regulated in rat retina. The neural specific isoform hnRNP-R2 is expressed in 7-day postnatal rat retina, but not in the adult retina. The positive immunohistochemistry signal of hnRNP-R1 is extensively distributed in the outer plexiform layer, inner nuclear layer and ganglion cell layer of rat retina. Double staining experiments showed that the positive signal of hnRNP-R1 is distributed in ON-type bipolar cells and localized in the cytoplasm, dendrites and axon terminals. In addition, the hnRNP-R1 distribution is regulated in rat retina during circadian. The present investigation suggests that hnRNP-R may play roles in retinal development and light-elicited cellular activities.