宁强矮马线粒体DNA D-loop区的遗传多样性

【目的】研究宁强矮马线粒体DNA（mitochondrial DNA，mtDNA）D-loop区的遗传多样性及其母系起源进化，为其遗传资源保护提供理论数据。【方法】采用PCR和测序技术分析12匹宁强矮马mtDNA D-loop区的600 bp核酸序列，并基于mtDNA D-loop区序列将宁强矮马和NCBI公布的其它马种进行系统树构建。【结果】宁强矮马群体存在9种单倍型，检测到34处SNP位点，占所分析位点总数的5.67%，各单倍型间的遗传距离为0.002—0.035，单倍型多样性为0.978±0.054，核苷酸多性为0.01988±0.00818。聚类分析表明宁强矮马分布在4个支系中，与胡克尔马、设特兰马、德保马、蒙古马和车巨马亲缘关系较近，与纯血马、云南马和韩国济州岛本土马的亲缘关系较远。【结论】宁强矮马具有比较丰富的遗传多样性，在进化的历史过程中受到其它马种的影响较大。

Genetic Diversity of Mitochondrial DNA D-loop Sequences in Ningqiang Pony

【Objective】In order to provide a scientific and theoretical basis for genetic resource protection of Ningqiang pony,the genetic diversity of mitochondrial DNA(mtDNA) D-loop and maternal origin of Ningqiang pony was investigated.【Method】 Twelve 600 bp mtDNA D-loop sequences were analyzed by PCR and sequencing techniques,and the phylogenetic trees were constructed based on the mtDNA D-loop sequences of Ningqiang pony samples and other equine D-loop sequence available from NCBI.【Result】There were 9 unique haplotypes with 34 polymorphic sites in Ningqiang pony,which account for 5.67% of 600 bp sequence analyzed.The haplotype diversity(h) and nucleotide diversity(π) were 0.978±0.054 and 0.01988±0.00818,respectively.Moreover,Ningqiang pony distributed in four branches,and are closely related to Hucul,Shetlan,Debao horse,Cheju horse and Mongolian horse,whereas they are less related to Thoroughbred,Yunnan horse and Jeju native horse.【Conclusion】 Ningqiang pony have rather abundant genetic diversity and were greatly affected by other horse breeds in history.