Characterization of WNT Signaling During Dorsal versus Ventral Iris-Derived Newt Lens Regeneration
There are many animals that have the ability to regenerate different tissues during embryonic stage, but only newts have the ability to regenerate whole organs throughout their entire life. Our primary focus is lens regeneration through transdifferentiation of pigment epithelial cells (PECs). This process has been previously shown to be highly topological, that is, trasdifferentiation always occur from the dorsal iris and never from the ventral iris. In order to understand why we have regenerative and non-regenerative tissues in dorsal and ventral iris, respectively, we examined the role and expression of several genes. My research aimed to discover the potential for ventral iris cell regeneration, through the in vivo manipulation of the Wnt pathway. The Wnt pathway regulates beta-catenin, which moves through the cytoplasm into the nucleus and binds to TCF/LEF transcription factor for transcription of target genes to occur. After staining with an antibody that detects the activated form of beta-catenin, we observed that beta-catenin is present at both ventral and dorsal nucleus at 12 days post lentectomy and not detected in the previous days. Knowing that the next step was to inhibit the Wnt pathway and observe the effects on lens regeneration. A beta-catenin/Tcf inhibitor chemical, called FH535 was injected to the newts every other day till 12 days post lentectomy. We hypothesized that there will be no lens development for either dorsal or ventral iris. Our preliminary results suggest that the chemical we used cannot inhibit lens regeneration from the dorsal iris. Future studies need to investigate further the importance of Wnt pathway during lens regeneration.