ANTIGENIC INTERRELATIONSHIP AND NUMBER OF INDEPENDENTLY SEGREGATING HISTOCOMPATI-BILITY LOCI IN THREE ISOHISTOGENIC STRAINS OF RATS

Abstract

The antigenic interrelationship between rat strains AS, BS, and HS, has been investigated by cross immunization experiments, and grafting from third strain donors to F₁ hybrid hosts from crosses between any two of the three strains. Six categories of antigens could be distinguished in these strains: three antigens (or groups of antigens) each of which is specific for one of the three strains; and three antigens (or groups of antigens) one of which is shared by any two of the strains but is absent in the third strain. An estimation was made of the number of independently segregating histocompatibility loci for each strain in respect of each of the other two strains. Estimates ranged from 8 to 14 loci. It is suggested that one to three important histocompatibility loci may be occupied by the same allele in all three strains.