Glial cell line-derived neurotrophic factor expression in the retina of adult zebrafish (Danio rerio).

The glial cell line-derived neurotrophic factor (GDNF) is a well-known growth factor acting on many neuronal populations of central, peripheral and autonomous nervous system. This factor was also previously detected in the retina of developing rat and chicken while no data are available for the zebrafish. In this study transcripts of GDNF mRNA were observed in adult retina extracts by RT-PCR. The presence of the GDNF protein was confirmed by SDS-PAGE and Western blotting analysis in adult retina homogenates. In situ hybridization and immunohistochemical experiments demonstrated that GDNF mRNA and protein localized in the photoreceptors, in the outer nuclear layer, in the inner plexiform layer and in the ganglion cell layer. These results showed that the expression of GDNF is not probably restricted during development but it might be involved in the physiology of adult zebrafish retina.