CHARACTERIZATION AND DEVELOPMENTAL REGULATION OF AVIAN CORNEAL BETA-1,4-GALACTOSYLTRANSFERASE RNA

Corneal development involves the synthesis and assembly of a number of specialized extracellular matrices. These matrices have distinctive p roperties derived from a unique assembly of collagens, proteoglycans a nd glycoproteins. The synthesis of each of these requires a number of enzymes. By probing a corneal cDNA library for genes that appeared to be up-regulated in cornea we have isolated a cDNA that represents an m RNA encoding the enzyme beta-1,4-galactosyltransferase. In cornea, a m ajor function for this enzyme is likely to be in the synthesis of the keratan sulfate proteoglycan, lumican. Employing quantitative reverse transcript-polymerase chain reaction, we have observed that the steady -state level of mRNA for the molecule is elevated during certain stage s of corneal development. It is also elevated in corneal fibroblasts i n culture that have a greatly decreased synthesis of the mature lumica n molecule. These data are consistent with, and complement, studies by others that show a corresponding regulation of the lumican core prote in during development and in corneal fibroblast cultures. (C) 1996 Aca demic Press Limited