Cataract development in the GalKO mouse.
BACKGROUND: Deletion of the gene for the enzyme alpha-(1,3) galactosyltransferase in the BalbC mouse generates the GalKO mouse, an animal which develops early bilateral cataract. The cause is not obvious. As part of studies to elucidate the mechanism involved, we have examined the rate of development and the location of opacities. METHODS: The development of cataract was monitored through daily observations on more than 200 animals from 50 litters. The first appearance of opacity was noted as well as the time at which the cataract was mature. Slitlamp photography was used to determine the location of the opacity. RESULTS: Without exception, every animal developed bilateral cataract. A white pinhead opacity was observed in one eye at an average age of 36 to 37 days and in the second eye, one to two days later. There was no apparent preference for either eye or for gender. Rapid progression to full opacities occurred, on average, within seven to eight days. Slitlamp photography revealed early nuclear and posterior cortical changes as well as fibre folds and swollen sutures. CONCLUSIONS: The GalKO mouse cataract appears to be an autosomal dominant trait. The nature and rapidity of the lens changes are indicative of severe biochemical alterations resulting in osmotic cataracts. It is possible this may be a novel cataract model.