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 paralogs of pax6 selleck products 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. It is possible that during the process of RPE transdifferentiation the alternative splice variants of pax6 observed here have different functions or different gene targets.

Collectively, these results suggest that upon retina removal at E4, the quiescent cells of the RPE dedifferentiate to become progenitor like cells similar to the cells of the optic vesicle that express the combination of eye field transcriptional factors and the factors sox2, c myc and klf4. This process is transient and not sustained if no growth Inhibitors,Modulators,Libraries factors are present. FGF2 allows for the sustained transcriptional activity of sox2, c myc and klf4 in retinal pigmented epithelium undergoing reprogramming towards retina progenitors To analyze the effect on the levels of expression of the pluripotency inducing factors during the process of RPE transdifferentiation, we performed surgeries at E4 in which FGF2 heparin coated beads were placed in the Inhibitors,Modulators,Libraries optic cup as previously described. Thereafter, the embryos were collected at different times.

In contrast with the expression patterns during injury in the absence of FGF2, the alternative splice variants pax6 5a and 5a were up regulated sim Inhibitors,Modulators,Libraries ultaneously from 6 h to 72 h. RPE transdif ferentiation was confirmed by a significant decrease in expression Inhibitors,Modulators,Libraries of mitf and tyr at 72 h PR. Immu nostaining revealed that c Myc, Sox2, Klf4 and the retina progenitor markers Pax6 and Chx10 were present at 72 h PR in the transdifferentiated RPE. In the absence of FGF2 at 72 h PR, the RPE did not trans differentiate and remained pigmented, expressing only c Myc, Klf4 and Lin 28, just as it does during normal development. As ex pected, in addition to transdifferentiated RPE, we also observed retina regeneration from the pool of stem progenitor cells located in the ciliary margin of the chick eye.

Thus, we conclude that FGF2 allows the sustained expression of sox2 and c myc in retina progenitor cells along with eye field transcrip Inhibitors,Modulators,Libraries tional factors to complete the transdifferentiation next pro gram of the RPE. In agreement with our results, destruction of photore ceptors by acute light lesions in zebrafish central retina re sults in M��ller glia dedifferentiation 4 to 8 h post lesion, exemplified by a strong Rx1 immunoreactivity.