Polymorphism of glycophorins in nonhuman primate erythrocytes

Abstract

Using immunoblotting techniques and polyclonal antisera to human erythrocyte alpha glycophorin, we show that erythrocytes of several species of nonhuman primates, including representatives of anthropoid apes (19 chimpanzees, 3 gorillas, 6 orangutans, and 3 gibbons) and Old World monkeys (3 baboons, 5 rhesus monkeys, and 6 cynomolgus macaques), contain human alpha glycophorin-like molecules. Each species displays a unique glycophorin profile; in anthropoid apes the profile is more complex than in Old World monkeys and more similar to that seen in humans. The chimpanzee was the only species in which human delta-like glycophorin was detected but it differed from its human counterpart in electrophoretic mobility and reaction with M-specific monoclonal antibody. In contrast to humans, highly polymorphic glycophorin profiles were observed in each species of anthropoid apes and three distinct patterns were defined in each. No such polymorphism has been found so far among the Old World monkeys in the limited number of animals studied. The major glycophorins in all species but the chimpanzees failed to react with M- or N-specific monoclonal antibodies, suggesting structural differences from the human within the amino terminal regions. The reaction with the minor glycophorins showed inter- and intraspecies variability. All glycophorins, except delta-like glycophorin in the chimpanzee, reacted with the antiserum to the carboxyl terminal fragment of human alpha glycophorin, indicating a structural relation to the human in this region. An unexpected correlation was observed, in the chimpanzee, between the patterns of electrophoretically resolved glycophorins and the V-A-B-D blood-group phenotypes, allowing the assignment of each determinant to specific glycophorin bands. The basis for the differences observed between human and nonhuman primate glycophorins is not clear but the possibilities include a common nonpolymorphic ancestor and differences in selective pressures.