Gene expression signatures in the newt irises during lens regeneration

Lens regeneration in adult newts is possible by transdifferentiation of the pigment epithelial cells (PECs) of the dorsal iris. The same cells in the ventral iris are not capable of such a process. To understand this difference in regenerative competency, we examined gene expression of 373 genes in the intact dorsal and ventral irises as well as in irises during the process of lens regeneration. We found similar signatures of gene expression in dorsal and ventral with several cases of even higher levels in the ventral iris. Such transcriptional activity in the regeneration-incompetent ventral iris was unexpected and calls for a revision of our views about mechanisms of lens regeneration induction.