Abstract
Abstract: :
Purpose: During an ethylnitrosourea mutagenesis screen, mice were tested for the occurrence of dominant abnormalities of the eye. The purpose of the study was morphologic description, mapping of the mutant gene, and test of candidate genes in a particular mutant, AEY12. Methods: Male C3Heb/FeJ mice were treated with ENU (3x100 mg/kg body weight) and mated to untreated female C3Heb/FeJ mice. Eyes were analyzed using a slit lamp. Linkage analysis was performed using 70 F2 carriers of the Aey12 phenotype after an outcross to C57BL/6 mice and a set of microsatellite markers covering all autosomal chromosomes. cDNA was amplified after reverse transcription of lens mRNA. For PCR, cDNA or genomic DNA was used as a template. Results: Aey12 mutants are mainly characterized by small eyes; other ocular dysmorphologies are variable and include corneal opacities, vacuolated lenses and even absence of lenses. The mutation was mapped to chromosome 10 in an interval of 5 cM between the markers D10Mit123 (4 cM from the centromer) and D10Mit168 (9 cM from the centromer). Candidate genes for the mutation include Soul, Pde7b and Eya4. Moreover, in the same chromosomal region, another cataract mutation, Cat5, was reported previously without further molecular analysis (Everett et al., Genomics 20, 1994, 429-434). Conclusion: There are now at least three different loci identified on mouse chromosome 10 responsible for proper development of the eye and the lens in particular: The Mip locus at position 74 cM from the centromer, the Cat3 locus at position 51 cM from the centromer and the Aey12 locus very close to the centromer. Ongoing molecular analysis of the Aey12 mutants will discover either a new important gene for eye development or a new function of an already known gene.
Keywords: 316 animal model • 338 cataract • 318 anterior segment