A mutation in the connexin 50 (Cx50) gene is a candidate for the No2 mouse cataract

Abstract
PURPOSE. The No2 cataractous mouse mutant displays a bilateral, congenital, hereditary nuclear opacity of the ocular lens. The aim of this work was to identify and subsequently screen an optimal candidate gene for a mutation correlated and consistent with the observed phenotype. METHODS. The No2 cataract was mapped in relation to genes and microsatellite markers by crossing to the wild mouse strain Mus spretus and then backcrossing to the inbred strain C3H/ HeH. The Cx50 (MP70) protein coding region and flanking sequences were amplified from normal parental as well as heterozygous and homozygous mutant genomic DNAs. These PCR products were then sequenced directly. Sequence data was corroborated by restriction analysis of PCR products. RESULTS. Mapping of the No2 cataract placed it in the vicinity of Gja8, the gene encoding connexin 50 (MP70), a major component of lens fiber gap junctions. Amplification and subsequent sequencing of the Cx50 protein coding regions revealed a single A ? C transversion within...