Abstract: Purpose : To establish a new modal system to evaluate the genetic toxicity of aneugens and to investigate the effects of colchicine (COL) on preimplantation embryo cells. Methods : Kunming mice were divided into 5 groups including solvent control , and COL-treatments (0. 00 mg/ kg , 0. 25 mg/ kg , 0. 50 mg/ kg and 0. 75 mg/ kg) . The mitotic index (MI) and micronucleus frequency(MNF) of cells from preimplantation embryos of mice were observed. Results :①The MI of the 0. 75 mg/ kg group was highly significant as compared to that of the control ( P < 0. 01) . ②MNF of 0.25 mg/ kg , 0. 50 mg/ kg and 0. 75 mg/ kg groups were 2. 99 ‰, 7. 35 ‰, 10. 13 ‰ respectively and presented a dose responsive relationship with COL. All of MNF of COL treated groups were highly significant as compared to that of control ( P < 0. 01) . Conclusion : ①A new reliable animal model for evaluating the genetic toxicity of aneuploidogen was established by a series of pre2test procedures. ②COL could arrest nuclear division of preimplantation embryo cells only when the dose reaches a certain level . COL may induce the aneuploidy of preimplantation embryos with dose response.

Key words: aneuploidy, preimplantation embryo, colchicine.