Purchase this article with an account.
Hongwei Ma, Arjun Thapa, Lynsie Morris, Stylianos Michalakis, Martin Biel, Mark Frank, Melissa Bebak, Xi-Qin Ding; Gene Expression Alterations in Mouse Retina with Deficiency of Cone Cyclic Nucleotide-gated Channel Subunits CNGA3 and CNGB3. Invest. Ophthalmol. Vis. Sci. 2013;54(15):4191.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
The cone photoreceptor cyclic nucleotide-gated (CNG) channel is essential for central and color vision and visual acuity. Mutations in the channel subunits CNGA3 and CNGB3 are associated with achromatopsia and cone dystrophy. We investigated the gene expression profiles in mouse retina with CNG channel deficiency using whole genome expression microarrays.
As cones comprise only 2-3% of the total photoreceptor population in the wild-type mouse retina, the mouse lines with CNG channel deficiency on a cone-dominant background, i.e., Cnga3-/-/Nrl-/- and Cngb3-/-/Nrl-/- mice, were used in our study. Retinal RNAs were prepared from Cnga3-/-/Nrl-/-, Cngb3-/-/Nrl-/- and Nrl-/- mice (at postnatal 30 days) and analyzed by Illumina microarrays. The microarray data were analyzed using a 5% FDR and functionally evaluated using Ingenuity IPA. QRT-PCR and western blotting were performed to confirm the microarray findings.
Comparative data analysis revealed a total of 105 genes altered in Cnga3-/-/Nrl-/- and 92 in Cngb3-/-/Nrl-/- retinas, relative to Nrl-/- retinas at 1.5-fold change, with 27 genes changed in both genotypes. The differentially expressed genes primarily encode proteins associated with cell signaling, cellular function maintenance, and gene expression. Ingenuity Pathways Analysis identified 26 and 9 canonical pathways in Cnga3-/-/Nrl-/- and Cngb3-/-/Nrl-/- retinas, respectively, with 6 pathways shared. The shared pathways include phototransduction, cAMP/PKA-mediated signaling, endothelin signaling, and EIF2/endoplasmic reticulum stress, whereas the IL-1, CREB, and purine metabolism signaling were found to specifically associate with Cnga3 deficiency.
CNG channel deficiency differentially regulates genes that affect cell processes such as phototransduction, cellular survival and gene expression, and such regulations play a crucial role(s) in the retinal adaptation to impaired cone phototransduction. Though lack of Cnga3 and Cngb3 shares many common pathways, deficiency of Cnga3 causes more significant alterations of gene expression. This work provides insight into how cones respond to impaired phototransduction at the gene expression levels.
This PDF is available to Subscribers Only