基于线粒体DNA对中国部分地方黄牛群体系统发育的研究

发布时间：2018-10-10 14:58

【摘要】：本研究采用PCR扩增产物直接测序法测定了中国6个地方黄牛群体553个个体的线粒体DNA D-环区(mtDNA D-loop)核苷酸长度为417bp的序列(包含高变区),包括宝鸡秦川牛群体(SQB,n=158)、早胜牛(早胜)群体(GZZ,n=148)、早胜牛(和盛)群体(GZH,n=36)、平凉地方牛群体(GPL,n=112)、固原地方牛群体(NGY,n=75)和临夏地方牛群体(GLX,n=24),并引用已经提交到GenBank中的中国其他49个地方黄牛群体611个个体的mtDNA D-loop区的所有序列,进而对中国55个地方黄牛群体的遗传多样性和系统发育展开系统的研究,旨在为中国地方黄牛群体的遗传资源评估、保护与可持续利用提供更多的科学依据。本研究得出结论如下:1.通过对中国55个地方黄牛群体1164个个体的mtDNA D-loop区核苷酸长度为417bp的序列进行分析,在没有考虑碱基的插入和缺失的情况下,总共检测到316个变异位点,核苷酸变异率为75.78%,包括199个单一多态位点和117个简约信息位点。突变类型总共有3种,即转换、颠换及转换与颠换共存,而且主要以转换为主。以上研究结果表明,中国55个地方黄牛群体mtDNA D-loop区遗传变异较高;2.碱基组成分析表明,A+T平均含量为61.3%,显著高于G+C平均含量38.7%,可见中国55个地方黄牛群体mtDNA D-loop区碱基A与T的含量较为丰富;3.基于检测到的316个变异位点,界定了356个单倍型(H1~H356),其中236个为特有单倍型,120个为共享单倍型。研究结果表明,我国地方黄牛群体在遗传结构上虽然具有特殊性,但是也与其他地方黄牛群体存在密切关系,或表明中国地方黄牛群体之间存在广泛的单倍型共享,即中国各个地方黄牛群体之间存在着广泛的基因交流;4.计算了中国55个地方黄牛群体的单倍型多样度(Hd±SD)、平均核苷酸差异数(k)和核苷酸多样度(Pi),并将各个群体的分别与整个群体总体单倍型多样度(Hd±SD)、平均核苷酸差异数(k)和核苷酸多样度(Pi)进行比较,结果显示我国地方黄牛群体拥有十分丰富的遗传多样性;5.构建的系统发育树和中介网络关系分析结果表明,中国地方黄牛群体主要有2种母系起源类型,一种是普通牛型(Bos taurus),另外一种是瘤牛型(Bos indicus)。
[Abstract]:In this study, direct sequencing of PCR amplification products was used to determine the nucleotide length of mitochondrial DNA D- ring region (mtDNA D-loop) in 553 individuals from 6 local cattle populations in China (including hypervariable region), including Baoji Qinchuan cattle population (SQB,n=158), early morning. GZZ,n=148, GZH,n=36, GPL,n=112, NGY,n=75 and GLX,n=24 were cited from 611 other 49 local cattle populations in China that had been submitted to GenBank. All sequences of the mtDNA D-loop region of the body, Furthermore, the genetic diversity and phylogenetic development of 55 local cattle populations in China were systematically studied in order to provide more scientific basis for the assessment, conservation and sustainable utilization of genetic resources of Chinese local cattle populations. The conclusions of this study are as follows: 1. The nucleotide sequence of mtDNA D-loop region of 1164 individuals from 55 local cattle populations in China was analyzed. A total of 316 mutation sites were detected without taking into account the insertion and deletion of the base. The nucleotide mutation rate was 75.78, including 199 single polymorphic sites and 117 parsimonic information sites. There are three types of mutation, namely, transversion, transversion and transversion. The results showed that there was high genetic variation in the mtDNA D-loop region of 55 local cattle populations in China. The analysis of base composition showed that the average content of, A T was 61.3%, which was significantly higher than that of G C, 38.7%. It can be seen that the contents of base A and T in the mtDNA D-loop region of 55 local cattle populations in China were relatively rich; 3. 356 haplotypes (H1~H356) were identified based on 316 mutation sites, of which 236 were endemic haplotypes and 120 were shared haplotypes. The results showed that although the genetic structure of local cattle populations in China is special, there is a close relationship with other local cattle populations, or there is extensive haplotype sharing among local cattle populations in China. That is, there is a wide range of genetic exchanges among cattle populations in various parts of China; 4. The Hd 卤SD), average nucleotide diversity (k) and nucleotide diversity (Pi),) of 55 local cattle populations in China were calculated, and the average nucleotide diversity (k) of each population was compared with that of the whole population (Hd 卤SD),). Compared with nucleotide diversity (Pi), The results showed that the populations of local yellow cattle in China were rich in genetic diversity. The results of phylogenetic tree and intermediary network analysis show that there are two maternal origin types in Chinese local cattle population, one is common cattle type (Bos taurus), the other is tumor-type (Bos indicus).
【学位授予单位】：甘肃农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S823.81

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