The importance of Rx has been demonstrated during retina re generation in pre metamorphic http://www.selleckchem.com/products/chir-99021-ct99021-hcl.html Xenopus laevis. We next evaluated the expression of pax6 transcrip tional factor, known to be a master regulator of eye de velopment. Different alternative splicing variants of pax6 have been identified in different vertebrates, with pax6 and pax6 being the most evolu tionary conserved. The alternative splicing of pax6 transcript generates both forms with the variant 5a that has an additional 14 amino acid residues inserted in the paired domain, resulting in different spe cific target genes. In the chick, pax6 is expressed in retinal progenitor cells in early stages of eye develop ment and later in ganglion, horizontal and amacrine cells.

To determine whether the expression of both alternative splice variants can be regulated in the injured RPE, we performed RT qPCR using specific primers for both pax6 and pax6. Although both variants were up regulated at 6 h PR, we observed a more prom inent up regulation of pax6 at 6 h PR. By con trast, pax6 showed a higher expression at 24 h PR. These data suggest that pax6 and are differentially regulated in the RPE after removing the retina. Interestingly, in the chick, when the optic vesicle is formed, the two splice variants of pax6 are expressed in both the central nervous system and the eye primor dium, with the pax6 variant being the most abun dant. In Xenopus laevis, pax6 is up regulated in RPE cells soon after removal from the choroid, and this expres sion is not dependent on FGF2, although the regulation of specific variants has not been explored.

In the same study, it was suggested that pax6 expression was triggered by the 72 h PR and processed for laser capture microdissec tion. In an attempt to avoid variation in the RPE collec tion, all samples were collected close to the FGF2 bead. The RT qPCR analysis demonstrated that the expression of sox2 and c myc was enhanced and sus tained up to 72 h, when the RPE is reprogrammed to wards retinal progenitors. We did not observe expression of oct4 and nanog under these condi tions. We also evaluated the levels of expression of eye field transcriptional factors and the expression of genes associated with the RPE phenotype. Our RT qPCR experiments demonstrated that the expression alteration of the cell extracellular matrix and or cell cell interactions.

It is possible that a similar effect can occur in the injured RPE in our system. Interestingly, zeb rafish has two selleckbio paralogs of pax6 that are required at different points of neuronal progenitor proliferation after light damage to the retina. During mouse brain development, Pax6 affects cell proliferation but not neural differentiation. By con trast, the canonical Pax6 affects cell proliferation and differentiation.