三种小型猪线粒体DNA控制区的比较研究

目的分析五指山小型猪、巴马小型猪和贵州香猪线粒体DNA控制区碱基序列，比较研究不同猪种的遗传标志。方法应用PCR技术分别对这三种小型猪的血液总DNA样品中线粒体DNA D-loop区进行扩增，测序比对。结果猪的线粒体DNA D-loop区分三个区域。I区（靠近5’端区域）704bp，五指山小型猪在此区共有6个变异位点，通过6个变异位点中归纳出3个单倍体，而巴马小型猪在此区有9个变异位点，通过9个变异位点归纳出4个单倍体，贵州香猪在此区共有6个变异位点，通过6个变异位点归纳出3个单倍体。Ⅱ区（串联重复序列区），五指山小型猪、巴马小型猪和贵州香猪序列相同。Ⅲ区（靠近3’端区域）三种小型猪的序列几乎相同。结论五指山小型猪、巴马小型猪和贵州香猪三种小型猪之间线粒体DNA碱基序列变异位点较少，五指山小型猪和巴马小型猪亲缘关系较近。

A Comparative Study of Mitochondrial DNA Control Regions in Three Breeds of Miniature Pigs

Objective To analyze the mitochondrial DNA control region sequences in Wuzhishan mini-pigs, Bama miniature pigs and Guizhou xiang pigs and to explore their cytoplasmic DNA markers. Methods The mtDNA D-loop regions in Wuzhishan mini-pigs, Bama miniature pigs and Guizhou xiang pigs was amplified and sequenced by PCR assay. Results The D-loop region of the mini-pigs was divided into three areas. Areas I, a 704 bp sequence at 5＇-end of the D-loopo In this area, Wuzhishan mini-pigs had 6 polymorphic sites. 6 polymorphic sites deduced 3 haplotypes, Bama miniature pigs had 9 polymorphic sites. 9 polymorphic sites deduced 4 haplotypes. Guizhou xiang pigs had 6 polymorphic sites, 6 polymorphic sites deduced 3 haplotypes. Areas Ⅱ , The tandem repeat sequence which was located in the middle of mtDNA D-loop, was identical in the three breeds of mini-pigs. Areas Ⅲ , the sequence at 3＇-end of the D-loop, which was very conservative, exhibited particularly high homology with the same region in the three breeds of miniature pigs. Conclusions The polymorphism of mtDNA D-loop within the three breeds of miniature pigs is poor.The genetic relationship of Wuzhishan mini-pigs and Bama miniature pigs is very close.