Testis-Organizing H-Y Antigen and the Cell Lineage-Specific Antigen of Testicular Sertoli and Ovarian Follicular Cells: H-2 Restricted and Nonrestricted Killing by Female T-Cells of Testicular Sertoli Cells
Although male specific, H-Y antigen is, as far as we know, ubiquitously expressed in every somatic cell type of the mammalian male. At first glance, the assignment of a specific organogenesis-directing function to an antigen so ubiquitously expressed might seem rather absurd. A second thought, however, should make everyone realize that the omnipresent expression might actually be the hallmark of organogenesis-directing antigens. In order to direct organogenesis, an antigen responsible for it has to express itself before the scheduled commencement of that organogenesis. Indeed in the development of mouse embryos, gonadal differentiation does not begin until the 12th day (Peters, 1970), yet H-Y antigen is first expressed ten days earlier in preimplantation male embryos of the eight-cell stage (Krco and Goldberg 1976). Its ubiquitous expression may be viewed as a tolerable consequence of the need to express itself very early in embryonic development. The expression of H-Y antigen by male extragonadal somatic cell types is clearly as superfluous as the maintenance of the Y by the same cell types. Witness the fact that the male bandicoot, belonging to the two marsupial genera Isoodon and Perameles, eliminates the Y and acquires an X0 sex chromosome constitution for many of his extragonadal cell types (Hayman and Martin, 1965).
KeywordsSertoli Cell Spleen Cell Leydig Cell Seminiferous Tubule Male Germ Cell
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