Continuous expression of the homeobox gene Pax6 in the ageing human retina

Purpose: In the past few years, the essential role of the homeobox gene Pax6for eye development has been demonstrated unambiguously in a variety of species including humans. In humans, Pax6mutations lead to a variety of ocular malformations of the anterior and posterior segment. However, little is known about PAX6 expression in the adult human retina. We have therefore investigated PAX6 levels and localization in the human retina at various ages. Methods: Adult human eyes of various ages (17-79 years) were obtained from the Zurich Eye Bank. PAX6 expression levels and patterns were analysed by Western blot analysis of total retinal protein and by immunohistochemistry on paraffin sections, respectively. Results: PAX6 expression in the retina was detected up to 79 years of donor age and was predominantly localized to the ganglion cell layer and the inner part of the inner nuclear layer. Conclusions: PAX6 remains distinctly expressed throughout the lifespan of the human retina suggesting a role for PAX6 in the retina after completion of eye morphogenesis.