Induction of dominant lethal mutations in male mice by fosfestrol.

Using the dominant lethal assay, the ability of fosfestrol, a diethylstilboestrol derivate, to induce mutations in male mice was tested and confirmed. Up to 300 mg/kg of fosfestrol the induction of mutations occurs exclusively in spermatozoa. A dose of 600 mg/kg of fosfestrol induces dominant lethal mutations up to 10 days posttreatment. The majority of induced dominant lethal mutations in all dose groups are expressed as loss after implantation.