Mutagen effects on rat seminiferous tubules in vitro: induction of meiotic micronuclei by adriamycin.

Mutagen effect on male germ cells can be analyzed by micronucleus induction during meiotic divisions. These can be followed in vitro by culturing seminiferous tubular segments from stages of the epithelial cycle that contain late pachytene and diakinetic primary spermatocytes. We studied the formation of micronuclei in this test system using adriamycin as a model mutagen. Micronuclei were induced in a dose-dependent manner at concentrations of 1-10 ng/ml that were far below the dose that caused morphologically or biochemically detectable cytotoxic effects. The meiotic micronucleus induction in vitro is a potentially sensitive test system of male germ cell mutagenesis.