Free H-Y antigen induces in vitro testicular differentiation of human XX embryonic indifferent gonads.

In accordance with the anchorage site hypothesis, Daudi beta 2-microglobulin (-) HLA (-) human male Burkitt lymphoma cells are incapable of stably maintaining H-Y antigen on their plasma membrane; instead, they excrete it into the culture medium. The proposed testis-organizing function of Daudi H-Y antigen in solution, previously demonstrated in bovine ovarian embryonic cells, has been tested for the first time in human undifferentiated gonads. Cultured in the presence of Daudi excreted H-Y antigen, gonads obtained from early human embryos of 46, XX chromosomal constitution underwent precocious and complete testicular differentiation.