中国小家鼠细胞色素b基因序列分析

目的]研究中国小家鼠的细胞色素b基因序列与DNA分类系统。方法]对来自陕西汉中、新疆乌鲁木齐、云南昆明、湖北武汉和台湾等18个地区的20只小家鼠个体进行基因组DNA提取，细胞色素b基因的PCR扩增和序列测定，并分析碱基组成，构建系统进化树。结果]20只小家鼠基因组大小均在20000bp以上；小家鼠细胞色素b基因序列中A、T、G、C的平均含量分别为31．6％、29．2％、12．2％和27．0％，个体间碱基组成几乎无差别；汉中、乌鲁木齐等长江以北的12个个体与舱m．musculw的系统发育关系为一支系，昆明、武汉、台湾等8个长江以南的个体与舱m．castanloes的系统发育关系较近。结论]中国小家鼠以长江为界，可分为南北2大亚种，南方为舱m．costalzues亚种，北方为胍m．musculus亚种。

Sequence Analysis of Cytochrome b of Chinese House Mice

Objective ] The aim was to study the cytochrome b gene sequence and DNA taxonomy of Chinese house mice. Method J Genomic DNA were extracted from 20 house mice from Hanzhong, Urumqi, Kunming, Wuhan, Taiwan in China, and then the eytochrome b gene were amplified and sequenced. The base composition eytochrome b gene was analyzed and the phylogenetic tree was constructed. Result] Genome sizes of 20 house mice were all over 20 000 bp. The average contents of A, T, G, C in eytochrome b DNA of 20 house mice were T： 29.2% , C： 27.0%, A： 31,6% , G： 12.2% , and the base compositions between individuals almost had no difference. The genetic relationship of 12 house mice which were distributed in the north region of the Yangtze River was near to M. m. musculus. The genetic relationship of 8 house mice which were distributed in the south region of the Yangtze River was near to M. m. castaneus. Conclusion] Chinese house mice comprise two subspecies, the house mice from north of Yangtze River belonged to M. m. musculus, the house mice from south of Yangtze River belonged to M. rn. castaneus.