[Human Y chromosome in reproduction and development].

The present status of human Y chromosome study is reviewed. A total of 13 genes, including two pseudogenes, have been mapped on the Y chromosome. They included colony stimulating factor receptor (CSF2R), SRY (TDF), ZFY, RPS4Y (ribosome protein 4S), ADMLY (Kallman syndrome), AMGL (amelogenin, which we cloned ourselves) and so on. In addition, the presence of two XY homologous genes is proposed. One increases performance IQ and the other reduces water-content of an embryo. We examined 54 azoospermic patients with an apparently normal Y chromosome. Each patient was analyzed for the presence or absence of 26 loci on the Y chromosome. Six showed a very small "micro" deletion. A common segment which is absent in every 6 patient has been identified. Cloning of azoospermia-related gene is being attempted using YAC clones.