Models for Neural Retina Regeneration: Transdifferentiation or Stem Cell Differentiation?

Jason Spence, Mayur Madhavan, David Jones, John Ewing and Katia Del Rio–Tsonis

Department of Zoology, Miami University, Oxford, OH 45056.

The embryonic chick can regenerate the neural retina upon removal during its early stages of development (stages 22-24). When the retina of a chick eye is removed, and FGF-2 is introduced into the optic cup, the retina is replaced by either transdifferentiation of the retina pigment epithelial (RPE) cells in the posterior of the optic cup or from the ciliary margin, most likely via stem cells. With the use of molecular/cell markers we compare these two processes by identifying the specification of different cell layers in a temporal manner, and identify stem cells located in the ciliary margin using neural progenitor cell markers. Molecules of interest such as Microphthalmia (Mitf), Pax-6, and Sonic Hedgehog (Shh) are currently being followed through normal development and throughout the process of retina regeneration in order to show regulation and interactions between these molecules.