IDENTIFICATION OF ALTERNATIVELY SPLICED VARIANTS OF TYPE-II PROCOLLAGEN IN VITREOUS

Adult and foetal bovine vitreous were analyzed for the presence of unp rocessed and partially processed forms of type II procollagen. Type II procollagen can exist in two alternatively spliced forms. a short for m which lacks a large part of the N-propeptide due to the splicing out of exon 2 and a long form in which exon 2 is expressed and which has a full-sized N-propeptide. Both splice variants were demonstrated and analyses of type II pN-collagen demonstrated that the long form predom inated, the ratio of the long form to the short form being 5:1 in foet al vitreous and 1.5:1 in adult vitreous. In foetal vitreous 35% of the type II collagen extracted was in the pN form, but there was very lit tle unprocessed type II procollagen or type II pC-collagen. In contras t, adult vitreous extracts contained relatively less type II pN-collag en, but contained larger amounts of type II pC-collagen and unprocesse d type II procollagen. (C) 1994 Academic Press, Inc.