Abstract
Abstract: :
Purpose: The Harwell ENU Mouse Mutagenesis Programme has generated 25 inherited eye disease models. Method: The Retinal White Spots (Rwhs) mouse, is among those that have been examined clinically and histologically, and mapped using an interspecific backcross. Results: The Rwhs mutant shows an ophthalmoscopic phenotype of adult-onset retinal white spotting with variable severity and progression. Histologically, the mutants show focal invaginations of the photoreceptor layer. Visual function appears to be preserved when assessed behaviourally in a visual tracking drum. Clinically and histologically the phenotype resembles the recessive Nr2e3rd7 mutant. The Rwhs phenotype shows autosomal dominant inheritance with decreased penetrance. Mapping localises the mutation to mouse chromosome 11, between markers D11Mit40 and D11Mit38 (between approximately 42.6 and 44.8cM). A candidate gene, Rtg4, lies in this region. Conclusion: Rtg4 has not until now been shown to be mutated in any inherited disease in the mouse. We suggest that Rwhs is a mutation in the Rtg4 gene. Rtg4 is the mouse orthologue of the human gene HRG4, which is homologous to the Caenorhabditis elegans gene unc-119.
Keywords: 562 retinal degenerations: hereditary • 316 animal model • 420 genetics