利用Y染色体遗传多样性对中国家马起源的研究

发布时间：2018-01-07 13:10

本文关键词：利用Y染色体遗传多样性对中国家马起源的研究　出处：《中国农业大学》2017年博士论文　论文类型：学位论文

【摘要】：野马自从被驯化为家马后,在人类的生活、生产和战争中,都发挥了重要作用。中国地方马的起源驯化问题一直存在争议。Y染色体由于其雄性特异性而被广泛应用于父系进化的研究,也为研究中国家马起源提供了新的视角。本研究包括23个中国地方马品种、4个引进品种,并以普氏野马和家驴作为对照,利用Y染色体上单核苷酸、微卫星和拷贝数变异三种遗传标记对中国地方马的起源进行了研究。主要的实验结果如下:(1)通过质谱分型技术对候选位点进行检测,在14个位点检测到了多态性。核苷酸多态性和单倍型多态性两个指标均显示中国地方马父系多样性显著高于国外引进品种。在NETWORK中,301个样品共形成20个家马单倍型,中国地方马在其中都有分布。SHT1和SHT2是地方马分布最为广泛的两个单倍型,SHT4到SHT20都由南方地方品种组成。SHT19和SHT20是AMELY基因发生突变形成的单倍型,其中AMELY的稀有等位基因与普氏野马的相同。SHT19和SHT20在遗传分化上与普氏野马有较近关系,推测这是一种古老的单倍型。(2)微卫星单倍型结果表明,引进品种单倍型单一,我国北方家马单倍型相对较少,南方家马单倍型丰富。携带有AMELY基因SNP突变样品的微卫星单倍型,与家驴遗传距离较近,是相对古老的单倍型。推测这种古老的单倍型,可能是起源于当地野马的驯化或者是北方家马扩散到南方地区而保留至今。(3)通过qPCR技术检测了 302个公马样本的11个多态位点的拷贝数变异。结果表明拷贝数变异在Y染色体多态性丰富,而这种变异主要来自于群体内部。除SNP9、SNP1、SNP12和SNP4位点所在片段外,其余位点CNV中位数群体间差异显著。FST遗传分化显示南方家马与引进品种遗传分化比北方家马更明显,遗传距离分析显示中国家马与中国邻近地域品种(阿拉伯马和阿哈捷金马)遗传距离更近,其中北方地方品种受周边品种影响较大。进化树结果显示驯化后的家马在中国呈现由北向南扩散的趋势。(4)通过焦磷酸技术对在8个位点有杂合现象的样品进行测序,发现部分位点两种碱基都是按照一定的比例存在,而另一些位点出现多种碱基比例并存的现象,并以其中某一种或几种为主。造成多种比例形式的情况,可能是由SNP和CNV突变时间先后顺序造成的,或者是源于外来个体的迁入。NSWG群体中的SNP17A拷贝数与现代家马存在显著性差异,表明其在起源上可能与其它群体存在明显不同。(5)对家马最初建系公马的个体数进行粗略估计,约有5匹公马参与到了家马初始群的建立。结论:联合家马Y染色体上的SNP、STR和CNV三种遗传标记分析中国家马起源驯化,中国家马最有可能是欧亚草原野马驯化后进入中国,再由北方地区扩散至全国,并且中国当地野马也存在驯化的可能,尤其是在家马父系多样性丰富的西南地区。
[Abstract]:Since the domesticated horse for horse, in human life, production and war, have played an important role. The origin of China where the domestication of the horse has been controversial research because of its male specific chromosome.Y and is widely used in the patriarchal evolution, but also provides a new perspective for the study of Chinese horse origin this study includes 23 Chinese local horse breeds, 4 varieties, and Przewalski's horse and donkey as control, using the Y chromosome single nucleotide, microsatellite copy number variation and origin of three kinds of genetic markers of Chinese horse were studied. The main results are as follows: (1) to detect by mass spectrometry genotyping the candidate loci, in 14 loci detected polymorphism. Nucleotide polymorphism and haplotype polymorphism two indicators showed the diversity of local China sire was significantly higher than that of the imported varieties in NETWOR. K, 301 samples were divided into 20 horse haplotypes, in which there are Chinese Ma local distribution of.SHT1 and SHT2 is the most widely two haplotypes for local horse distribution, SHT4 to SHT20 by the southern local varieties composed of.SHT19 and SHT20 mutations in the AMELY gene of AMELY haplotypes, including rare alleles gene and Przewalski's horse of the same.SHT19 and SHT20 in genetic differentiation and Przewalski's horses have a close relationship, that this is one of the oldest haplotype. (2) microsatellite haplotypes showed that single haplotype varieties in northern China, horse haplotype is relatively small, the South horse rich. Carrying microsatellite haplotype haplotype AMELY gene SNP mutation samples, and the donkey genetic distance is close, is relatively old. That this ancient haplotype haplotype, domestication may be originated from local or northern Mustang horse spread to the South Square area has been preserved. (3) detected by qPCR copy number variation of 302 male horse samples of the 11 loci. The results showed that the copy number variation in Y chromosome polymorphism, and this variation is mainly from the internal groups. Except for SNP9, SNP1, SNP12 and SNP4 loci in the fragment, the differences between groups were.FST median CNV loci genetic differentiation of Southern horse and introduced varieties of genetic differentiation is more obvious than the North horse, genetic distance analysis showed that Chinese and Chinese horse adjacent geographical varieties (Arabia horse and horse Ahajie) closer genetic distance, the north by the surrounding local varieties of varieties of influence. The phylogenetic tree results the domesticated horse show show diffusion trend from the south to the north in Chinese. (4) by pyrophosphate sequencing of heterozygous phenomenon samples in 8 sites, found that some sites are two bases There is according to a certain proportion, and some sites appear a variety of base ratio coexist, and in which one or several. Caused by a variety of forms of the ratio, probably by SNP and CNV mutations caused by time sequence, or from foreign individuals moved into.NSWG groups in the copy number of SNP17A with the modern horse there was a significant difference, indicating that it may exist in the origin and other groups were significantly different. (5) the number of individual horse stallion was originally built, a rough estimate, there are about 5 stallions involved in the horse initial group established. Conclusion: the combination of horse chromosome Y SNP, STR and CNV three genetic markers analysis of domestication China horse, Chinese horse is most likely to enter the Chinese wild Eurasian steppe after domestication, the northern region to spread across the country, and there may be China local horse domestication, especially In the rich diversity of the southwestern region of the family marpatine.

【学位授予单位】：中国农业大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：S821.2

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