Abstract
Abstract: :
Purpose: Characterize the phenotypes of an ENU–induced mouse vitreous mutation BEMV5 and determine the chromosome location of this gene mutation. Methods:The eye phenotype of these mice was evaluated by indirect ophthalmoscope. The chromosome location of the BEMV5 gene was determined by genome–wide linkage analysis. The cellular phenotypes were further characterized using standard light microscopy and histology, immunohistochemistry, and electron microscopy. Glucose tolerance test was performed in mice to determine their glucose sensitivity. Results: BEMV5 is an autosomal recessive mutation that display whitish, glistening deposits in the vitreous, scattered around the optic nerve head. The deposits are detectable with indirect ophthalmoscope from at least two weeks of age and do not appear to progress with age. By light and transmission electron microscopy, the deposits have a globular morphology with diameters ranging 10–500nm. Homozygous BEMV5 mice are viable, but develop many other phenotypes such as fatty liver, female infertility, and glucose hypersensitivity. Genome–wide linkage analysis has mapped BEMV5 mutation to mouse chromosome 19. Conclusions: The vitreous deposits in BEMV5 mice seem to be asteroid bodies or vascular remnants. Therefore, BEMV5 is likely to be the first mouse model for asteroid hyalosis or unique atrophies of the hyaloid vascular system in the eye. Further detailed characterization of these phenotypes and identification of BEMV5 mutation will provide molecular insights of an important disease gene mutation that lead to the phenotypes in different organs including eye, liver, and ovary.
Keywords: genetics • linkage analysis • gene mapping