Overview on sex determination and Sexual ambiguity (part 1)

Alfred Jost, the French Physiologist (1974) (1), in some magnificent experiments, showed that all castrated rabbit embryos, before sex differentiation, produced female offspring regardless of the chromosomal constitution (2). Male gonads and their essential hormones, i.e. anti-Mullerian factor to inhibit Mullerian development and testosterone to initiate the Wolfferian growth and convert the urogenital sinus to male external genitalia (3), are required to produce a male embryo. He also delineated that if a piece of the rabbit testis was transplanted to embryos with female chromosomal karyotypes whose gonads were to differentiate into ovaries, the differentiation process changed to produce the testes. He reached the conclusion that all embryos naturally produced female offspring regardless of the chromosomal constitution (2-3)