Ontogeny and localization of the alpha-, beta-, and delta- crystallin antigens during lens development in mallard embryos.

The ontogeny of alpha-, beta-, and delta-crystallin antigens in the developing lens of mallard (Anas platyrhynchos) was investigated by indirect immunofluorescence using specific antibodies to mallard alpha-, beta-, and delta- crystallins raised in rabbits. The IgG fraction from each antiserum was isolated by affinity chromatography usign Protein A Sepharose CL-4B. Fluoresceinee (FITC) or rhodamine (TRITC) conjugated goat anti rabbit (GAR) gamma-globulin was used as the secondary antibody. The results show that alpha-, beta-, and delta-crystallins appear simultaneously in the developing mallard lens and are detectable from 66 hr (stage 15/16). This situation is different from the chick where delta- is known to appear first followed by beta-, and alpha-. This could be due to species variation. In the epithelium, however, as in the chick, delta- emerges first followed by beta-, and alpha- but rather late when compared with the chick and this seems probably due to a difference in the incubation time between the two species. Results from immunofluorescence and Tris-SDS gel electrophoresis demonstrate that alpha A subunit of the alpha-crystallin appears much earlier than the alpha B subunit. We also found that the newly discovered epsilon-crystallin (18) appears long after the three major crystallin classes.