Blood groups of pig-tailed macaques (Macaca nemestrina).

The human-type A-B-O blood groups of 57 pig-tailed macaques (Macaca nemestrina) were determined and the calculated gene frequencies, O = 0.8908, A = 0.0825 and B = 0.0267, gave excellent fit with the hypothesis of inheritance by triple allelic genes. In tests for simian-type blood groups with rhesus, baboon and crab-eating macaque immune antisera, it was shown that the red cells of pig-tailed macaques are polymorphic for several simian-type specificities defined by those cross-reacting sera. Pig-tailed macaques share with other macaque species the complex Drh-graded blood group system, which seems to occupy a special role among red cell antigens of macaques. Normal sera of three female macaques contained spontaneous isoagglutinins which selectively agglutinated the red cells of some pig-tailed as well as stump-tailed macaques.