SEROLOGICAL DETECTION OF HISTOCOMPATIBILITY ANTIGENS IN TWO STRAINS OF RATS

Abstract

The erythrocytes of two inbred strains of rats, Lweis and B.N., differ because of antigens 1 and 3, respectively, which are determined by alelic genes. The survival times of Lewis and B.N. skin homografts on rats of an F2 hybrid population were evaluated with respect to the correspondence between donor and host for these antigens. Homografts did not survive longer than 12 days in any case where an incompatibility existed, although a significant number of grafts were maintained longer on hosts compatible for antigens 1 or 3. The data suggested that the antigens were products of an important histocompatibility locus. Genetic tests showed the genes determining antigens 1 and 3 to be in the same chromosome linkage group as that determining rat antigen B (4) and indicated a possible allelic relationship. Cytotoxic antibodies developed in some F2 hybrids following hyperimmunization with Lewis or B.N. tissues. The presence of cytotoxic antibodies in the few F2 hybrids tested was unrelated to their possession of the 1 and 3 antigens, suggesting that the Lewis and B.N. strains differ for an additional, independent system of serologically distinguishable antigens.