title: Targeted knockdown of Cerkl, a retinal dystrophy gene, causes mild affectation of the retinal ganglion cell layer.
abstract: In order to approach the function of the retinal dystrophy CERKL gene we generated a novel knockout mouse model by cre-mediated targeted deletion of the Cerkl first exon and proximal promoter. The excised genomic region (2.3kb) encompassed the first Cerkl exon, upstream sequences including the proximal promoter and the initial segment of the first intron. The Cerkl-/- mice were viable and fertile. The targeted Cerkl deletion resulted in a knockdown more than a knockout model, given that alternative promoters (unreported at that time) directed basal expression of Cerkl (35%). In situ hybridizations and immunohistochemistry showed that this remnant expression was moderate in the photoreceptors and weak in the ganglion and inner cell layers. Morphological characterization of the Cerkl-/- retinas did not show any gross structural changes, even at 12 months of age. However, some clear and consistent signals of gliosis and retinal stress were detected by the statistically significant increase of i) the glial fibrillary antigen protein (GFAP) expression, and ii) apoptosis, as detected by TUNEL. Remarkably, consistent non-progressive perturbation (from birth up to 12 months of age) of ganglion cells was supported by the decrease of the Brn3a marker expression as well as the reduced oscillatory potentials in the electroretinographic recordings. In conclusion, the Cerkl-/- knockdown shows a mild retinal phenotype, with increased levels of cellular stress and apoptosis indicators, and clear signs of functional alteration at the ganglion cell layer, but no detectable morphological changes.
authors.affiliation: Departament de Genètica, Facultat de Biologia, Spain.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Garanto
authors.forename: Javier
authors.initials: J
authors.lastname: Vicente-Tejedor
authors.forename: Marina
authors.initials: M
authors.lastname: Riera
authors.forename: Pedro
authors.initials: P
authors.lastname: de la Villa
authors.forename: Roser
authors.initials: R
authors.lastname: Gonzàlez-Duarte
authors.forename: Román
authors.initials: R
authors.lastname: Blanco
authors.forename: Gemma
authors.initials: G
authors.lastname: Marfany
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004596:Electroretinography; D005091:Exons; D005260:Female; D005838:Genotype; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000096:biosynthesis / Q000172:deficiency* / Q000235:genetics; D011401:Promoter Regions, Genetic; D012160:Retina / Q000201:enzymology* / Q000473:pathology; D058499:Retinal Dystrophies / Q000201:enzymology / Q000235:genetics; D012165:Retinal Ganglion Cells / Q000201:enzymology* / Q000473:pathology*
chemical_list: D017853:Phosphotransferases (Alcohol Group Acceptor); C530392:CerkL protein, mouse