Specific Polypeptides in Prenatal Bovine Alpha‐crystallin

The development of the eye lens in the prenatal phase is accompanied by a gradual change in the polypeptide composition of α‐crystallin. As the lens matures from that of a 6‐week‐old embryo to that of a new‐born calf, there is a successive appearance of different polypeptides although two obviously principal polypeptides, A2 and B2, are present at every stage of development. The youngest embryonic lenses studied contain four polypeptides. Two of them differ from the well‐known polypeptides as found in cortical bovine α‐crystallin.