TI - Loss of AND-34/BCAR3 expression in mice results in rupture of the adult lens . AB - Purpose AND-34/BCAR3 ( Breast Cancer Anti-Estrogen Resistance 3 ) associates with the focal adhesion adaptor protein , p130CAS/BCAR1 . Expression of AND-34 regulates epithelial cell growth pattern , motility and growth factor dependence . We sought to establish the effects of the loss of AND-34 expression in a mammalian organism . Methods AND-34-/- mice were generated by homologous recombination . Histopathology , in situ hybridization and western blotting were performed on murine tissues . Results Western analyses confirmed total loss of expression in AND-34-/- splenic lymphocytes . Mice lacking AND-34 are fertile and have normal longevity . While AND-34 is widely expressed in wild type mice , histologic analysis of multiple organs in AND-34-/- mice is unremarkable and analyses of lymphocyte development show no overt changes . A small percentage of AND-34-/- mice show distinctive small white eye lesions resulting from the migration of ruptured cortical lens tissue into the anterior chamber . Following initial vacuolization and liquefaction of the lens cortex first observed at postnatal day three , posterior lens rupture occurs in all AND-34-/- mice , beginning as early as three weeks and seen in all mice at three months . Western blot analysis and in situ hybridization confirmed the presence of AND-34 RNA and protein in lens epithelial cells , particularly at the lens equator . Prior data link AND-34 expression to the activation of Akt signaling . While Akt Ser 473 PHOSphorylation was readily detectable in AND-34+/+ lens epithelial cells , it was markedly reduced in the AND-34-/- lens epithelium . Basal levels of p130Cas PHOSphorylation were higher in AND-34+/+ than in AND-34-/- lens epithelium . Conclusions These results demonstrate the loss of AND-34 dysregulates focal adhesion complex signaling in lens epithelial cells and suggest that AND-34 -mediated signaling is required for maintenance of the structural integrity of the adult ocular lens .