The lens proteins in adult and embryos of the periodic albino mutant ofXenopus laevis

Abstract

The crystallins of normal and a^p mutants ofX. laevis have been studied using biochemical (electrophoresis in agar and polyacrylamide gels, isoelectric focusing) and immunochemical methods (immunoelectrophoresis, immunodiffusion, immunoabsorption, immunofluorescence, isoelectrofocusing with immunoidentification). The immunochemical analysis was carried out with rabbit antisera prepared against electrophoretic fractions of the mutant lens.Crystallins of adultX. laevis (a^p/a^p; ++/++) are heterogenous as judged by electrophoretic mobility, isoelectric point, antigenic and species specificity.No qualitative nor quantitative differences were found between crystallins of normal and mutant animals at the level of the protein subunits. These conclusions, however, are valid only for those crystallins, which are solubilized at pH 9.0.Immunofluorescence studies showed that crystallins appear in the normal and mutant embryos at practically the same time. No significant differences in the appearance of specific immunofluorescence between the normal and mutant embryos were found.Some of the gamma and, perhaps, beta-crystallins appear first; alpha-crystallins appear later. It has been shown for the first time that some gamma-crystallins are formed at advanced developmental stages.The periodic albino mutation does not affect the function of genes coding for crystallins either in embryos or in the adultX. laevis.

Keywords: Crystallins; Eye rudiment; Periodic albino mutant; Xenopus laevis.