Stephen S. Wachtel

H-Y antigen in the study of sex determination and control of sex ratio

Abstract It has been proposed, on the basis of widespread phylogenetic conservation, that H-Y antigen is the inducer of primary sex, causing the undifferentiated XY gonad to become a testis in male heterogametic species such as the human and bovine. That proposition has withstood extensive testing in vivo and in vitro. Freemartin gonads are H-Y+, for example, and masculinization of the freemartin gonad has been attributed to soluble H-Y, borne and transmitted in the serum of the bull twin, and bound in ovarian receptors of the female. We have applied monoclonal H-Y antibodies to the identification of gender in embryos of the bovine. Our preliminary results imply presence of H-Y in bovine embryos of the morula and blastocyst stages recovered at about 6–12 days of gestation. Assignment of H-Y phenotype -- positive in males and negative in females -- allows selective implantation of male and female during embryo transfer. Thus in an early study, we correctly identified gender in 6 of 7 calves born healthy at term, after transfer of 8 blastocysts.

On the secretion of H-Y antigen

It has been proposed that H-Y antigen secreted by cells of the Sertoli lineage is bound by receptors on these and other cells of the primordial gonad and thereby initiates formation of the testicular cords, and that H-Y is not an integral transmembrane component but a part of a ternary system with beta 2-microglobulin and products of the MHC. It follows that cultured Daudi cells, which lack beta 2-microglobulin and HLA, should secrete H-Y. This is consistent with evidence obtained with monoclonal H-Y antibody and an ELISA. By this method, free H-Y was demonstrable in the supernatant fluids of cultured Sertoli cells and Daudi cells. The assay provides a useful alternative to detection of H-Y in the complement-dependent cytotoxicity test.

46,XY gonadal dysgenesis: Isoncogenesis related to H-Y phenotype or breast development?

SummaryAmong women with 46,XY gonadal dysgenesis, there is a high incidence of gonadal tumors. Because of evidence of a connection between occurrence of those tumors, H-Y phenotype, and breast development, we surveyed 55 cases of 46,X gonadal dysgenesis and 12 related cases involving chromosomal and/or skeletal abnormalities. Our survey, including three new cases presented here, indicates that H-Y phenotype but not breast development may be related to the development of the gonadoblastoma-dysgerminoma. Thus among women with 46,XY gonadal dysgenesis, there are H-Y− and H-Y+ classes, but gonadal tumors are found almost exclusively in the H-Y+ class. Yet one of our patients may represent an exception to the association of H-Y+ phenotype and gonadal tumors in this syndrome.

H-Y Antigen in the Chicken

To determine whether asymmetrical development of the chicken ovary could be related to differential expression or function of H-Y antigen, the putative ZW ovary inducer, we compared the ability of cells from the left and right gonad to absorb H-Y antibodies in 17-day chick embryos and in one-day-old hatchlings. In addition, we studied uptake of soluble H-Y antigen by gonadal cells in 17-day embryos, one-day-old hatchlings, and young adults. Indications are that H-Y is present in the left gonad of the female, and to a lesser extent in the right, and not in the testes of the male. Our preliminary results indicate moreover that the right ZW gonad may lack receptor sites for soluble H-Y at around the time of hatching. It may be inferred that expression of H-Y antigen is a prerequisite of ovarian development in birds, although it remains to be determined unambiguously whether H-Y is the primary inducer of the ZW gonad or an accessory molecule involved in some intermediate aspect of gonadal development.

Gonadal tumors in patients with gonadal dysgenesis and sex chromosomal rings and fragments

Patients with female phenotypes and dysgenetic gonads harboring testicular tissue have a markedly increased risk of developing gonadal tumors. Cytogenetic demonstration of Y chromatin is the currently accepted criterion for performing prophylactic gonadectomies in these women. We studied four patients with dysgenetic gonads containing either testicular tissue or germ cell tumors. All had small sex chromosomal fragments which could not be characterized by conventional cytogenetic studies. Clinical features, DNA replication studies, and immunologic assays of Xga and H-Y antigens failed to correlate consistently with the gonadal histology. We recommend prophylactic gonadectomies and subsequent hormone replacement in all patients with female phenotypes, gonadal dysgenesis, and cytogenetically indeterminate sex chromosomal fragments.

H-Y typing in the ELISA

In a series of quantitative absorptions, biotin-conjugated monoclonal H-Y antibody was reacted with a plated source of H-Y antigen in the ELISA. H-Y was demonstrated in testis supernatant fluid of the mouse in this system, and in cells from males of the mouse, bovine and human and females of the chicken, thereby confirming its evolutionary persistence, and underscoring its presumptive role in the primary determination of vertebrate sex.

Detection of H-Y in the enzyme-linked immunosorbent assay

SummaryWe have developed a new enzyme-linked immunosorbent assay for determination of H-Y phenotype in the human. This assay, which measures the inhibition of the reaction of a monoclonal anti-H-Y antibody and a mouse testis extract as a source of H-Y antigen, was applied to the supernatant of lymphocytes from ten normal male and ten normal female subjects. Introduction of supernatant from male cells gave reading of 69%–78% of those obtained with testis supernatant alone; female-cell supernatant did not inhibit the reaction (89%–102%).

H-Y ANTIGEN, SEX DETERMINATION AND GENDER CONTROL

All things considered it looks as though Utopia were far closer to us than anyone … could have imagined … Indeed, unless we choose to decentralize and to use applied science, not as the end to which human beings are to be made the means, but as the means to producing a race of free individuals, we have only two alternatives to choose from: either a number of national, militarized totalitarianisms, having as their root the terror of the atomic bomb and as their consequence the destruction of civilization (or, if the warfare is limited, the perpetuation of militarism); … or else one supra-national totalitarianism, called into existence by the social chaos resulting from rapid technological progress in general and the atomic revolution in particular, and developing, under the need for efficiency and stability, into the welfare-tyranny of Utopia. You pays your money and you takes your choice.

On the Nature of H-Y Antigen

To avoid polemical discussion, it should be noted that the term H-Y antigen has been used by current authors to designate the molecule identified by antibodies from male-grafted female mice [3]. Yet there is some question whether that molecule is the same as the H-Y transplantation antigen which causes rejection of intrastrain male-to-female skin grafts; and there are recommendations that the former be called SDM for’ serologically detectable male’ antigen [8, 9].