University of Plovdiv “P. Hilendarski”, Faculty of Biology, BG-4000 Plovdiv, Bulgaria
TOMOVA, E., 2009. Tissue expression of a and b blood group antigens in small intestines of Eurasian tree sparrow (Passer montanus) and goldfinch (Carduelis carduelis). Bulg. J. Agric. Sci., 15: 441-445
Tissue localization, molecular mechanisms, functions and importance of the A and B blood group antigens (BGA) in the evolution of vertebrate animals have not been fully clarified. Their exploration can elucidate those aspects and their significance in the evolutionary process. In this work, for the first time, we studied the tissue expression of A and B BGA on the length of the intestines of the class Aves - Passer montanus and Carduelis carduelis. We applied biotin-srteptavidin-peroxidase system on paraffin cuts. As primary antibodies for immune histochemical study we used monoclonal antibodies against human A and B BGA.
Along the length of the intestine we proved a modulating expression of the antigens searched. The epithelial cells of lamina epithelialis are permanently positivized and the glands in lamina propria. Near the end of the small intestines, the intensity of immune peroxidase reaction decreases. At the end of the organ of Carduelis carduelis the expression of A and B blood group antigens disappears. These results can hardly be explained with species specificity and evolutionary level of the animals. Or rather, the possible leading role has the selective inclusion of genetically encoded glycosyltransferases responsible for blood group expression, with no clear limiting factors and unlocking mechanism of their biosynthesis, either.