α-crystallin polypeptides in developing chicken lens cells

We provide evidence that the different cells that form the chicken lens have isoelectric variants of α-crystallins at early and late developmental stages. We separated the αA and αB-crystallin subclasses by sodium dodecylsulphate polyacrylamide gel electrophoresis and then further resolved each by isoelectric focusing and assays with specific anti α-crystallin antibodies. We found that the annular pad, cortical and nuclear fibers, as well as the epithelial cells, contain αA and αB native chains and their respective isoelectric variants. These results on adult and embryonic lenses obtained a short time after the onset of α-crystallin expression suggest that lens cells, having different phenotypes, are able to produce post-translational modifications of the αA and αB chains as a part of their developmental program.