A New Mouse Model of a Late Onset Retinal Degeneration

Abstract

Purpose: : To characterize the genetics and phenotype of a new mouse mutant with a late onset retinal degeneration named nm3482.

Methods: : We have identified a new mouse model of a late onset retinal degeneration by screening mouse strains and stocks at The Jackson Laboratory for genetic mouse models of human ocular disorders. We characterized the clinical effects of this mutation using serial electroretinography (ERG), fundus photography, and histology, and performed genetic analysis including linkage studies.

Results: : In this new mutant (nm3482), ERG shows a normal response at one month of age, but lower rod-mediated ERG response and normal cone-mediated ERG response at two months of age and no rod-mediated ERG response and poor cone-meditated ERG response at 4 months of age. Histological slides show a normal retinal structure at 3 months of age, but a retinal degeneration at 4 months of age (retinal outer nuclear layer ONL degenerates to 6 layers) and a completed retinal degeneration at about 12 months of age. Fundus examination shows a normal retina (fundus) at 6 months of age, but typical retinal degeneration at 8 months of age. Our genetic analysis shows that the nm3482 is an autosomal recessive mutation and it is mapped to mouse Chromosome 5, the human homolog should be on 12q24 or 7q11.

Conclusions: : Late onset retinal degeneration combined with our genetic data suggests that it is a new retinal phenotype not previously described in mouse. This provides a novel mouse model for a late onset retinal degeneration.

Keywords: gene mapping • retinal degenerations: hereditary • genetics