Purpose
Alternative splicing generates proteome complexity from a limited number of protein coding genes. Alternative splicing factors are proteins that regulate the inclusion/exclusion of an exon in the final mRNA. We wanted to understand the role of AS in retinal development and disease as this is not clearly understood. To this end, we investigated the role of Serine/arginine rich splicing factor 10 (Sfrs10), an alternative splicing factor in mouse retinal development.
Methods
We employed RT-PCR and immunohistochemistry to determine the expression of Sfrs10 across retinal development in different strains (CD1, C57BL6, & FVB) of mice. Finally, we employed P0 in vivo electroporations to knockdown Sfrs10 in the developing retina.
Results
We found that Sfrs10 was expressed across retinal development. At P0, Sfrs10 expression was seen in ganglion cells, followed by amacrines at P4, bipolars, horizontals and red/green cones at P8-14, rods by P22 and the expression remained the same in P90 and P720 retinae in CD1 mice, an albino strain. Here we found that in C57/Bl6 strain expression was similar to that of CD1 in regards to the inner nuclear layer (INL) and the ganglion cell layer (GCL), but there was no expression observed in the outer nuclear layer (ONL) at P9. Later at P22, retina from C57BL6 mice showed cone expression, but not in rods. Surprisingly, at P240 only the INL and GCL expression was maintained, there was no expression in the ONL. In contrast, in FVB, expression in rods was observed as early as P10. Finally, in CD1 mice, electroporation of RNAi at P0 results in rods with shorter outer segments and wider apical ends.
Conclusions
Expression of Sfrs10 is modified by strain background. Sfrs10-mediated AS might be required for terminal differentiation of retinal neurons. Specifically it is required for rod outer segment morphogenesis.
Keywords: 688 retina •
698 retinal development •
695 retinal degenerations: cell biology