Abstract
Purpose: :
The CNGA3-/- mouse is an animal model lacking the A subunit of the cone specific cyclic nucleotide gated channel. The phenotype is characterized by a loss of cone photoreceptor function and a progressive degeneration of the cones. To elucidate the biological events leading to the loss of photoreceptors we combined mRNA expression experiments with whole genome miRNA expression profiling.
Methods: :
Expression analysis of CNGA3-/- and wildtype retinas in 2 age stages was performed using Affymetrix MOE 430 2.0 microarrays. Differential regulated transcripts with a minimum change in expression level of 1.5 fold with a p-value less than 0.05 were obtained and gene regulation networks were generated by the Ingenuity Pathways Analysis software. To verify the data 10 transcripts per time point were analyzed by qRT-PCR. miRNA expression profiling was conducted on a whole genome mouse miRNA array. The study was performed in accordance with the ARVO Statement for the use of Animals in Ophthalmic and Visual Research.
Results: :
496 transcripts were differentially regulated in the retinas of the 4 week old mice and 204 in those of the 8 week old animals. Gene regulation networks revealed misregulations of genes associated with RNA post-transcriptional modification and cellular growth. 80 % of the transcripts chosen for real-time validation could be verified. In the miRNA array analysis of 4 week old mice we found several differently regulated miRNAs which have potential target genes included in the differential gene list of our previous transcriptional analysis.
Conclusions: :
Expression analysis of the CNGA3-/- mouse highlighted a misregulation of the phototransduction cascade in accordance with the loss of visual function that characterizes the phenotype. The combination of mRNA and miRNA expression profiling permits a closer monitoring of the neurodegenerative events in the retina occurring during the course of degeneration.
Keywords: gene microarray • retinal degenerations: hereditary • genetics