Suppression of lens gamma-crystallin encoded by Len-1 in the mutant mouse with eye lens obsolescence (Elo).

Eye lens obsolescence (Elo) is a heritable, autosomal dominant eye disorder in mice. The Elo mutation lies close to the Len-1 locus on mouse chromosome 1, and it was speculated that the Elo locus affects the expression level of gamma-crystallin. To clarify this, we used the BASO-DALT system to compare the amount of lens gamma-crystallin between Elo and normal mice. The lens extracts from 10-day-old Elo mice revealed the same profiles and expression levels of alpha- and beta-crystallins as those of +/+ mice. Among gamma-crystallins, the amounts of the components encoded by Len-1 were lower than wild-type levels, but that encoded by Len-2 was not in the Elo mouse. NaDodSO4-gel analysis revealed that the lower gamma-crystallin level could be detected as early as the 14-day stage in the lens of the Elo mouse embryo. The suppression of gamma-crystallin gene expression in Elo mice was examined at the mRNA level. The concentration of gamma 2-crystallin mRNA in Elo mice lens was estimated at 1/13 of that of normal lens, indicating that a small amount of transcript production from gamma-crystallin genes may cause the low level of gamma-crystallin in Elo lens.