MALE STERILITY AND AN AUTOSOMAL TRANSLOCATION IN ROMNEY SHEEP

Five closely related Romney sheep are described. All showed centric fusion of wo acrocentric chromosomes, forming a submetacentric chromosome. One sheep, a ram, had abnormally shaped testicles, was sterile and showed persistent aspermatogenesis. Meiotic chromosome studies on primary spermatocytes from this sheep showed 24 or 25 bivalcnts and a trivalent instead of the 27 bivalents seen in normal rams. The sex bivalent was not involved in the tri- valent, which confirmed this to be an autosomal translocation. It is suggested that the sterility of this sheep was possibly genetically determined in the same way as in male mice with a similar chromosome translocation. © 1969 S. Karger AG, Basel.