Abstract: Purpose: This study was designed to evaluate the effects of two methods, hormone induction ovulation(HIO) and culture in vitro maturation (CVM), on the quality and chromosomal complements in mouse oocytes. Methods: 100 matured mouse oocytes were obtained by HIO and 80 by CVM. Their chromosomal complements were prepared and analyzed. Results: The hyper haploid rate, aneuploid rate, chromosomal structurally aberration rate, structurally aberrated oocyte rate, degenerative oocyte rate and mean number of splitting chromosomes in HIO group were 2.0 ％,4.0 ％,2.0 ％, 2.0 ％, 8.0 ％ and 0.13 subsequently, and were 4.0 ％, 8.0 ％, 7.5 ％, 6.3 ％, 12.5 ％ and 0.32 5 in CVM group. All the parameters between two groups are not signifi cantly different. Conclusion: The qualities and chromosomal complements of mouse oocytes obtained by CVM were not naturally different from those by HIO. Extrapolating to human, this result suggested that the maturation in vitro of immature oocyte would have great potential for human assisted reproduction.

Key words: oocyte, culture in vitro maturation, hormone induction ovulation, chromosomes