Ontogeny and localization of the alpha, beta, and gamma crystallins in newt eye lens development

The alpha-, beta-, and gamma-crystallins, proteins characteristic for the vertebrate eye lens, have been localized in the developing lens of Notophthalmus viridescens, the eastern spotted newt. Using the immunofluorescence technique, antibodies to the alpha-, beta-, and gamma-crystallin classes were applied to tissue sections through the eye region of developing N. viridescens embryos, Harrison (external) Stages 30 to 46+. beta-Crystallins were the first of the crystallins to appear in a few cells of the lens vesicle even before the lengthening of the prospective primary fiber cells. gamma-Crystallins were first detectable at a slightly more advanced stage in the prospective primary fibers, and alpha-crystallins in a few cells of the beginning primary fiber area. The external layer/epithelium was negative for beta-crystallins until late in lens morphogenesis, and alpha- and gamma-crystallins could not be detected in these cells at any time. This, the first use in amphibia of homologous antibodies specific for the crystallin classes, makes clear that phylogenetic differences exist as to the primacy and relevance of specific crystallins to events during morphogenesis of the eye lens.