Immunohistochemical study of ontogeny and phylogeny of a terminal N-acetylglucosamine cluster antigen.

In this work an immunohistochemical method was used to study the ontogeny and phylogeny of a terminal N-acetylglucosamine (GlcNAc) cluster antigen which is an epitope(s) of highly branched N-linked oligosaccharides terminating in GlcNAc residues. The ontogenic studies demonstrated that expression of the antigen is developmentally regulated in lymphocytes, epithelial cells of endodermal origin and kidney mesangial cells of the chicken. The antigen was found in several other avian species studied, namely, the Japanese quail, duck, goose and turkey. Furthermore, the distribution of the antigen in all these species was similar. In adult animals, it was found in bursal and thymic lymphocytes, macrophages, spleen reticulum cells, epithelial cells of the intestine and bronchioles and capillary endothelial cells. The antigen was also detected in epithelial cells of the gastrointestinal tract of several lower vertebrates studied: the amphibian (frog), reptile (chameleon) and fish (rainbow trout). It was undetectable in various organs of the human, African green monkey, calf, pig, rat and guinea-pig, but was found in the intestinal epithelial cells of ten mouse strains. It is likely that biosynthetic processing leading to the formation of highly branched N-linked glycans terminating in GlcNAc residues is conserved during evolution in birds and other lower vertebrates.