Abstract
Abstract: :
Purpose: To discover genes expressed at higher levels in the rd (retinal degeneration) retina than in the wildtype. Such genes would either be upregulated during the degeneration process, or constitutively upregulated in the inner retina. Methods: Retinas were collected from 90-day-old wildtype and rd/rd mice. mRNA was purified and used for the production of complex radiolabelled cDNA probes, which were used to screen pairs of mouse and human macroarrays (GDA, Incyte). Clones that were differentially expressed were obtained and rescreened using slot blot hybridization. Two selected gene products which were upregulated in the rd phenotype were studied further using Western blot analysis and immunocytochemistry. Results: The hybridisation signal per µg RNA for both the selected genes, neuroleukin and Mel-1N, was found to be higher in the rd phenotype than in the wildtype. Immunocytochemistry showed labeling of the inner retina at equal strength in both phenotypes. There was no labeling of wildtype photoreceptor cells. Conclusion: Our results illustrate that in the absence of photoreceptors, the relative contribution of inner retinal transcripts is strongly enhanced even though their expression is not appreciably altered in absolute terms. The identification of genes expressed in the inner but not the outer retina is of interest not least for the possibility to drive promoter expression specifically to the inner retina in transgenic analysis.
Keywords: 417 gene/expression • 557 retina: proximal(bipolar, amacrine, and ganglion cells) • 554 retina