COMPARATIVE INVESTIGATIONS ON WATER-SOLUBLE CRYSTALLINS OF THE EMBRYONIC, FETAL, AND POSTNATAL HUMAN LENS DURING DEVELOPMENT AND AGING

To compare the crystallin composition of embryonic and fetal human len ses with those of postnatal and adult lenses, we investigated the crys tallins of lenses of various ages (from the 5th gestational week to 55 years) by gel chromatography, isoelectric focusing, immunodiffusion, and immunoelectrophoresis. Age-related changes were calculated as rela tive percentages of the different classes and subclasses of crystallin s. During prenatal lens development the percentages of both high-and l ow-molecular-weight alpha-crystallins as well as gamma-crystallins gra dually increased, whereas the percentage of beta-crystallins decreased . A considerable change in crystallin composition was found immediatel y after-birth: the relative percentage of beta-crystallins increased w hereas that of gamma-crystallins decreased. Gel-filtration analysis of crystallins from juvenile and adult lenses showed a high-molecular-we ight peak, which was not found in extracts from fetal and ne new-born lenses.