EXPRESSION OF PAX-6 DURING URODELE EYE DEVELOPMENT AND LENS REGENERATION

Regeneration of eye tissues, such as lens, seen in some urodeles invol ves dedifferentiation of the dorsal pigmented epithelium and subsequen t differentiation to lens cells. Such spatial regulation implies possi ble action of genes known to be specific for particular cell lineages and/or axis. Hox genes have been the best examples of genes for such a ctions. We have, therefore, investigated the possibility that such gen es are expressed during lens regeneration in the newt, The pax-6 gene (a gene that contains a homeobox and a paired box) has been implicated in the development of the eye and lens determination in various speci es ranging from Drosophila to human and, because of these properties, could be instrumental in the regeneration of the urodele eye tissues a s well. We present data showing that pax-6 transcripts are present in the developing and the regenerating eye tissues. Furthermore, expressi on in eye tissues, such as in retina, declines when a urodele not capa ble of lens regeneration (axolotl) surpasses the embryonic stages, Suc h a decline is not seen in adult newts capable of lens regeneration. T his might indicate a vital role of pax-6 in newt lens regeneration.