Spermatogenic failure in male mice lacking H–Y antigen

Abstract

The mammalian Y chromosome carries a factor that initiates male sexual development by directing the fetal gonads to form testes. Wachtel and his colleagues¹ proposed that this testis-determining function of the Y is mediated by the male-specific cell-surface antigen H–Y, originally defined by skin grafting². This attractive hypothesis, which has been widely accepted, was based on the assumption that serological tests using antisera raised against male cells were recognizing H–Y antigen. Although disputed³, this assumption is supported by some recent studies^4–6. However, mice have been described⁷ which develop testes but lack the cell-surface H–Y antigen as defined by T-cell-mediated transplantation tests. Thus, although it remains possible that a serologically detected male-specific antigen is responsible for testis determination, it seems that H–Y, as originally defined, is not. We show here that H–Y-negative male mice, in losing the genetic information that encodes H–Y, have also lost genetic information required for spermatogenesis. This result identifies a gene on the mouse Y,distinct from the testis-determining gene, which is necessary for spermatogenesis, and raises the intriguing possibility that the product of this ‘spermatogenesis gene’ is H–Y antigen.