A Molecular Approach to the Study of the Human Y Chromosome and Anomalies of Sex Determination in Man

The primary event of sex determination is the differentiation of the indifferent fetal gonad into a testis or ovary. The simplest hypothesis is that a dominant Y-linked gene(s) — the testis-determining gene (TDY) — encodes a single factor, the testis-determining factor (TDF), which induces testicular development. Of course, more-complex models can be envisaged, and the postulated TDY has not been accurately mapped or cloned. For this purpose, the construction of genomic libraries from the human or mouse Y chromosome has been achieved by several groups (Bishop et al. 1984, 1985; Wolf et al. 1985). Such libraries have allowed a rapid advance in understanding the structure of the human Y chromosome.