The H-Y antigen and its role in natural transplantation.

A concise overview of the transplantation biology of the H-Y antigen is presented with particular reference to: its prototypic behavior as a weak transplantation antigen; the facility with which mice of certain inbred strains can be rendered tolerant of H-Y incompatible skin grafts; its capacity to instigate graft-versus-host reactions; its significance in clinical transplantation; and finally, H-2 control of anti-H-Y immune responses. The role of the H-Y antigen in natural transplantation, i.e. pregnancy, is then reviewed. Evidence is presented to support the hypothesis that in certain cases maternal immune responses directed specifically to the H-Y antigen can exert selective pressures on male zygotes, producing deviant sex ratios in certain experimental and clinical situations.