Serology of H-Y Antigen

H-Y antigen and homosexuality in men.

In men, sexual orientation correlates with the number of older brothers, each additional older brother increasing the odds of homosexuality by approximately 33%. It is hypothesized that this fraternal birth order effect reflects the progressive immunization of some mothers to Y-linked minor histocompatibility antigens (H-Y antigen) by each succeeding male fetus, and the concomitantly increasing...

Serology with Lipid Antigen

H-Y antigen and the growth of the dominant gonad.

The evolutionary conservation of H-Y antigen and its expression in the heterogametic sex regardless of whether this is male or female must mean that the antigen is associated with a common denominator underlying the development of mammalian testes and avian ovaries. It is suggested that one such common denominator is an enhanced growth rate of the dominant heterogametic gonad at a critical stag...

H-Y antigen and the evolution of heterogamety.

In natural populations of platyfish, Xiphophorus maculatus, there are three sex chromosomes--W, X, and Y. Females may have one of three genotypes: WY, WX, or XX, and males may have either XY or YY. The W chromosome can be considered a modified X that blocks the male-determining function of the Y. The platyfish may represent an evolutionary stage at which female heterogamety arises through a sin...

H-Y antigen in a fertile XY female horse.

The presence of significantly reduced levels of H-Y antigen in the blood of an XY mare is consistent with the view that H-Y genes comprise a system of testis determinants. Loss or suppression of a critical portion of H-Y genes and subthreshold expression of H-Y antigen could account for a failure of testicular differentiation, thereby allowing a measure of ovarian development in an XY embryo.