HUMAN MALE-FERTILITY - Y-LINKED GENES AND SPERMATOGENESIS

Using a positional cloning approach, we have isolated a new gene famil y, the Y-located RNA Recognition Motif genes (YRRM), which constitutes a candidate for AZF, the 'azoospermia factor' located principally wit hin band Yq11.23, and thought to be important in the control of human spermatogenesis. The YRRM gene family has at least 15 members, more th an one of which are transcribed, some of which are pseudogenes. RNA in situ hybridization to adult human testis tissue indicates that gene e xpression of the YRRM family is confined to germ cells, notably sperma togonia and/or primary spermatocytes. Similar patterns of hybridizatio n are seen for a second gene family, TSPY, clustered mainly on the sho rt arm of the human Y chromosome. Both YRRM and TSPY show Y chromosome conservation in several mammalian species.