Comparative investigations on water-soluble crystallins of the embryonic, fetal, and postnatal human lens during development and ageing.

To compare the crystallin composition of embryonic and fetal human lenses with those of postnatal and adult lenses, we investigated the crystallins 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 relative percentages of the different classes and subclasses of crystallins. During prenatal lens development the percentages of both high- and low-molecular-weight alpha-crystallins as well as gamma-crystallins gradually increased, whereas the percentage of beta-crystallins decreased. A considerable change in crystallin composition was found immediately after birth: the relative percentage of beta-crystallins increased, whereas that of gamma-crystallins decreased. Gel-filtration analysis of crystallins from juvenile and adult lenses showed a high-molecular-weight peak, which was not found in extracts from fetal and new-born lenses.