[Role of HY antigen in human and mammalian gonadal organogenesis (author's transl)].

H-Y (histocompatibility Y) antigen plays a role in gonadal organogenesis, which is poorly understood. Indeed, it is not immunologically well-defined. The use of cytotoxicity tests cannot lead to a right quantification of its expression. In vertebrates, it is a marker of the heterogametic sex. As it is also detected in invertebrates, H-Y antigen is therefore ubiquitous and has a high phylogenic conservation. Its role, as an organizer of mammal testes, was carried out by controversial experiments of dissociation-reorganization, in gonadal cells. In gonads. H-Y antigen can be studied under 3 diverse aspects : secretion, fixation and expression, Recently, Ohno proposed a very attractive pattern of testicular and ovarian organogenesis. In males, organization of seminiferous tubules is the result of the interaction between H-Y antigen and its specific gonadal receptor. In females, primordial follicle formation is induced by the interaction between an hypothetic ovary-organizing antigen (similar to H-Y antigen) and the same specific receptor as in testis. These different hypotheses are discussed. In addition, it is underlined how expression of H-Y antigen (anchorage site of H-Y antigen on plasma membrane associated with beta 2-m) can be distinguished from its fixation on gonadal specific receptors. In view of controversial data, the masculinisation of bovine free-martin gonads by H-Y antigen is discussed. In XX males and XY females, H-Y expression which is variable is correlated with its gonadal organizing role. Finally, at present time location of H-Y structural and control genes remains unsolved. In view of all hypotheses postulated, it is not clearly demonstrated how H-Y antigen can act on gonadal organogenesis. Nevertheless, priority of cell-cell recognition, via H-Y antigen, has to be emphasized.