Testing for the chemical induction of aneuploidy in the male mouse.

Dyad scores of metaphase II spermatocytes in the mouse have been used as an end point to assess the aneuploidy-inducing potential of three different chemicals; p-fluorophyalanine, phenylalanine and 6-mercaptopurine. The sensitivities of three different spermatogenic stages have been tested; pre-leptotene, zygotene and metaphase I. No effect was found at any treated stage for 6-mercaptopurine and phenylalanine. p-Fluorophenylalanine, when compared to control treatments, did, however, induce non-disjunction when applied at metaphase I. It also caused a delay to spermatogenesis when applied at this stage. The potential of mammalian test systems for the routine screening of chemicals as non-disjunction inducers, is discussed.