基于cytb基因分析建昌马和安宁果下马的遗传多样性和起源进化

Genetic diversity,origin and evolution of Jianchang horse and Anning pony based on Cytb gene

为探索建昌马和安宁果下马的遗传多样性和亲缘关系,试验从建昌马(n=40)和安宁果下马(n=4)的抗凝全血中提取基因组DNA,用PCR扩增线粒体DNA cytb基因全序列并直接测序.结果显示,在44匹马中检测到cytb基因的45个变异位点并鉴定出20种单倍型,其中H1为优势单倍型;建昌马的单倍型多样性(Hd)、核苷酸多样性(Pi)和平均核苷酸变异数(K)分别为0.894±0.038、0.00499±0.00064和5.691.对23个马品种的遗传距离分析显示,建昌马与柴达木马的遗传距离最小(0.0036),与安宁果下马的遗传距离为0.0043,网络聚类图显示建昌马在7个(A-G)单倍群中,与单倍型系统进化树结果一致.结果表明,建昌马和安宁果下马的cytb基因具有丰富的遗传多样性,且均有多个母系起源,建昌马与柴达木马的亲缘关系最近,与安宁果下马的亲缘关系较近.

In order to explore the genetic diversity and genetic relationship between Jianchang horse and Anning pony,the genomic DNA was extracted from anticoagulant whole blood of Jianchang horses(n=40)and Anning ponies(n=4),and the genetic diversity of mtDNA cytb gene was assayed by PCR and direct sequencing.The results showed that 45 mutation sites were detected in 44 sequences of cytb gene.A total of 20 haplotypes were identified,among which H1 was the dominant haplotype.The Hd,Pi and K of Jianchang horse were 0.894±0.038,0.00499±0.00064,5.691,respectively.In the genetic distance analysis of 23 breeds,it was found that the genetic distance between Jianchang horse and Chaidamu horse was the minimun(0.0036),and the genetic distance between Jianchang horse and Anning pony was 0.0043.The network cluster map showed that Jianchang horse existed in 7 haplogroups(A-G),which was consistent with the result of haplotype phylogenetic tree.In conclusion,the cytb gene is rich in genetic diversity of Jianchang horse and Anning pony,showing multiple maternal origins,Jianchang horse and Chaidamu horse has the closest genetic relationship,and the genetic relationship between Jianchang horse and Anning pony is close.