The role of H-W and H-Y antigens in avian and mammalian gonadal differentiation

The mechanisms of genotypic sex determination and phenotypic sex differentiation have been studied in a variety of animal systems. Mammals and birds have been extensively studied because of experimental accessibility and correlations with human sexual development. One theory of sexual determination and differentiation based on genic inheritance involves the expression of the gene for the histocompatibility-Y cell surface antigen, or H-Y antigen. In the mammalian XX/XY mechanism of sex determination, H-Y antigen is present in the male, while in the avian ZZ/ZW mechanism H-W antigen is present in the female.;The aim of this work was to study the role of the H-W antigen in avian gonadal differentiation and to determine the relationship between the H-Y antigen which is involved in mammalian testicular differentiation and the avian H-W antigen postulated to be involved in ovarian differentiation.;To determine the role and relationship of H-W and H-Y antigens in avian and mammalian gonadal differentiation, studies were conducted on the effects of H-W and H-Y antigen and/or antibody on: (1) gonadal differentiation of avian embryos in ovo; (2) dissociation/reassociation cultures of fetal chicken or bovine gonadal cells; and (3) dissociation/reassociation cocultures of fetal chicken and bovine gonadal cells.;The results of these studies were: (1) the antigens are identical or cross-reactive immunologically and functionally; (2) the H-Y (H-W) antigen has a masculinizing effect on mammalian gonadal cells and a feminizing effect on avian gonadal cells; and (3) the absorption of the H-Y (H-W) antigen with H-Y (H-W) antibody disrupts the masculinizing effect of the antigen on mammalian gonadal cells and the feminizing effect on avian cells.