Persistence of crystallin messenger RNA's with reduced translation in hereditary cataracts in mice.

In vitro translation experiments showed that the lens fiber cells of two hereditary cataracts in mice (Nakano and Philly) possessed a full complement of crystallin messenger RNA's, despite severely reduced synthesis of crystallin in these cells. The reduction in synthesis in the lens fiber cells correlated with the increase in Na+ and the decrease in K+, which occurs during cataractogenesis. In contrast to the fiber cells, the epithelial cells continued to synthesize crystallins in the cataractous lenses. Crystallin synthesis was stimulated in the fiber cells by raising the K+ concentration and lowering the Na+ concentration in the cultured lenses. The reduction in crystallin synthesis in the initial stages of cataractogenesis in the Nakano and Philly lenses thus appears to be due to poor utilization of crystallin messenger RNA's in the fiber cells.