Lens epithelial proliferation cataract in segmental trisomy involving mouse Chromosomes 4 and 17

A dominant induced mutation in the mouse, tightly associated with a recipro cal chromosomal translocation between Chrs 4 and 17, causes abnormal head t ossing and circling behavior (the translocation induced circling mutation. Tim). Affected mice develop an unusual anterior subcapsular cataract that a ppears after birth and is progressive. The most likely explanation for the phenotypic observations is that the translocation breakpoint disrupted a ge ne or its regulation. Although the Mos protooncogene is located close to th e translocation breakpoint and transgenic mice that overexpress Mos demonst rate cataracts and circling behavior, there were no gross changes in the Mo s gene or in its level of expression. The morphological changes observed in the lens resemble those seen in some human congenital cataract syndromes.