广西3个地方黄牛品种mtDNA D-loop区序列多态性及起源分析

Origin and Polymorphism of Mitochondrial DNA D-loop Sequences in Three Guangxi Cattle Breeds

[目的]探究广西3个地方黄牛品种线粒体DNA控制区(mtDNA D-loop区)序列的多态性及其母系起源,为广西地方黄牛品种的选育、系统分类和开发利用提供科学依据。[方法]利用PCR扩增、测序和生物信息学方法对广西3个地方黄牛品种(南丹黄牛、隆林黄牛和涠洲黄牛)mtDNA D-loop序列进行多态性分析与系统发育进化树构建。[结果]从广西3个地方黄牛品种127个个体mtDNA D-loop区序列中检测到27种单倍型,其核苷酸多态位点65个,多态位点占所测核苷酸总长(908~912 bp)的7.143%,其中有61个转换、3个颠换和1个转换/颠换共存。广西3个地方黄牛品种mtDNA D-loop区单倍型多样度(H)为0.339~0.795,核苷酸多样度(π)为0.31%~2.54%,表明广西3个地方黄牛品种mtDNA D-loop区的遗传多样性存在较大差异,其中,南丹黄牛具有更丰富的遗传多样性,隆林黄牛次之,涠洲黄牛的遗传多样性较贫乏。聚类分析结果表明,广西3个地方黄牛品种具有普通牛和瘤牛2大母系起源,受瘤牛起源影响更明显。[结论]广西3个地方黄牛品种具有瘤牛和普通牛两大母系起源,但受瘤牛影响更明显。隆林黄牛与南丹黄牛为瘤牛和普通牛的混合母系起源,而涠洲黄牛为纯正的瘤牛母系起源,因此,应加强对广西地方黄牛品种资源,尤其是对涠洲黄牛品种资源的保护力度。

[Objective] In order to explore the polymorphism and maternal origin of mitochondrial DNA control region(mtDNA D-loop region) of three Guangxi cattle breeds and provide a scientific basis for the breeding, systematic classification, development and utilization of Guangxi Cattle Breeds. [Method] PCR amplification, sequencing and bioinformatics were used to analyze the polymorphism analysis and phylogenetic tree construction of mtDNA D-loop sequences of three Guangxi cattle breeds. [Result] 27 haplotypes were detected from 127 individual mtDNA D-loop sequences of three Guangxi cattle breeds. There were 65 nucleotide polymorphic sites, accounting for 7.143% of the total nucleotide length(908-912 bp), including 61 transitions, 3 transversions and 1 transformation/transversion. The haplotype diversity(H) of mtDNA D-loop region of three Guangxi cattle breeds was 0.339~0.795, and the nucleotide diversity(π) was 0.31%~2.54%, indicating that there were great differences in the genetic diversity of mtDNA D-loop region of the three Guangxi cattle breeds. Among them, Nandan cattle had richer genetic diversity, Longlin cattle took the second place, and Weizhou cattle had poorer genetic diversity. The results of cluster analysis showed that the three Guangxi cattle breeds had two maternal origins of taurine cattle and indicine cattle, and were more affected by the origin of indicine cattle. [Conclusion] Three Guangxi cattle breeds had two matrilineal origins of taurine cattle and indicine cattle, but they were more affected by indicine cattle. Longlin cattle and Nandan cattle were the mixed maternal origin of taurine cattle and indicine cattle, while Weizhou cattle was the pure maternal origin of indicine cattle. Therefore, the protection of variety resources in three Guangxi cattle breeds, especially the variety resources of Weizhou cattle, should be strengthened.