HISTOCOMPATIBILITY ANTIGEN IN THE HETEROGAMETIC SEX IN THE CHICKEN

Abstract

In two of the highly inbred Reaseheath lines of chickens female-to-male skin grafts, matched for the strong B locus, were reacted against with moderate strength. In the other three sex combinations occasional very much weaker reactions were seen, indicating slight residual heterozygosity within the lines. Since the female is the heterogametic sex in birds, this is evidence for the existence of a histocompatibility antigen analogous with the Y antigen of mammals. Confirmation of the existence of this heterogametic antigen as an immunological entity was obtained from the behavior of second-sets from the same and other females. Most first-sets induced tolerance for themselves following initial reaction, and in these cases the state of tolerance extended to a repeat graft from the same female and to grafts from other females. In the one case of total rejection of the first-set, immunity was developed leading to total rejection of the repeat graft and of grafts from two other females.