INVESTIGATION OF THE HUMAN RH BLOOD-GROUP SYSTEM IN NONHUMAN-PRIMATESAND OTHER SPECIES WITH SEROLOGIC AND SOUTHERN BLOT ANALYSIS

To investigate the evolution of the Rh blood-group system in anthropoi d apes, New and Old World monkeys, and nonprimate animals, serologic t yping of erythrocytes from these species with antibodies specific for the human Rh blood-group antigens was performed. In addition, genomic DNA from these animals was analyzed on Southern blots with a human Rh- specific cDNA. Consistent with earlier reports, serologic results show ed that gorilla and chimpanzee erythrocytes had epitopes recognized by human Rh D and c antisera, and gibbon erythrocytes were recognized by the c antisera. Surprisingly, some Old and New World monkeys also exp ressed a Rh c epitope on their erythrocytes. No erythrocytes from the nonprimate animals reacted specifically with any of the human Rh antis era. Southern blot analysis with a human Rh-specific cDNA probe detect ed Rh-related sequences in anthropoid apes, all New and Old World monk eys, and in most nonprimate animals tested. Although some Rh-related r estriction fragments were conserved across species lines in primates, the Rh locus was more polymorphic in chimpanzees and gorillas than in humans. In addition, restriction fragments segregating with the presen ce of the D antigen in humans were present in the primate species that expressed the D antigen.