The fungicide carbendazim induces meiotic micronuclei in the spermatids ofthe rat testis

Whether the fungicide carbendazim affects the meiotic spermatocytes and con sequently induces chromosome aberrations in the spermatids was determined i n the adult rat testis using the micronucleus test. Round spermatids contai ning micronuclei (MN) were significantly increased in number at stages I an d V on days 1 and 4.5 after treatment with carbendazim (100 mg/kg), respect ively (p<0.05). Immunocytochemistry indicated that approximately 68% of the carbendazim-induced MN contained kinetochores. These results suggest that carbendazim induces chromosome aberrations in spermatids with a high incide nce of aneuploidy.