基于线粒体基因的广西变色树蜥种群分子系统关系与遗传多样性

发布时间：2019-03-29 06:22

【摘要】：物种分子系统关系是进化生物学领域最基本也是最重要的问题之一。本研究通过测序分析了来自广西等地90个变色树蜥Calotes versicolor的ND2-tRNA基因片段,分析了不同地理种群的单倍型、种群间的遗传分化程度(F_(st))和历史动态,构建了单倍型之间的分子系统关系。结果发现,所研究的地理种群共检测到45个单倍型,总体呈现较高的单倍型多样性(0.941 8)和较低的核苷酸多样性(0.005 5),其中有6个地理种群的个体共享1个单倍型。大部分种群间F_(st)值较高且差异显著,遗传分化程度较高。分子方差分析结果表明,遗传变异主要来自种群内的遗传差异。系统进化分析结果表明,所研究的地理种群并没有出现明显的遗传分支且在地理上没有严格的分布范围和分化,这可能是由于种群间存在渐渗杂交或不完全的谱系筛选。网络关系图也显示各采样种群间不存在明显的谱系结构。种群历史动态分析表明,各地理种群不存在扩张现象。把所有地理种群合并在一起分析表明,贝叶斯轮廓图分析与碱基错配分析方法均检测到种群在历史上发生过快速扩张,约0.05 Ma前存在种群扩张现象。
[Abstract]:Species molecular system relationship is one of the most basic and important problems in the field of evolutionary biology. In this study, the ND2-tRNA gene fragments of Calotes versicolor from 90 species in Guangxi and other regions were sequenced. The haplotypes of different geographical populations and the degree of genetic differentiation (F _ (st) and historical dynamics) among populations were analyzed. The molecular phylogenetic relationship among haplotypes was constructed. The results showed that a total of 45 haplotypes were detected in the geographical populations, showing a higher haplotype diversity (0.941 8) and a lower nucleotide diversity (0.005 5), and that the population was characterized by high haplotype diversity (0.941 8) and low nucleotide diversity (0.005 5). One haplotype was shared among the individuals of 6 geographical populations. The F _ (st) value of most populations was higher and the difference was significant, and the degree of genetic differentiation was higher. The results of molecular variance analysis showed that the genetic variation mainly came from the genetic differences within the population. Phylogenetic analysis shows that there are no obvious genetic branches and no strict distribution and differentiation in the studied geographical populations, which may be due to the existence of impermeable hybridization or incomplete pedigree screening among populations. The network diagram also shows that there is no obvious pedigree structure among the sampled populations. The analysis of population history shows that there is no expansion phenomenon in each geographical population. The combination of all geographical populations shows that Bayesian profile analysis and base mismatch analysis both detect rapid population expansion in history, and population expansion occurs before about 0.05 Ma.
【作者单位】：广西壮族自治区药用植物园;广西动力技工学校;广西师范学院;
【基金】：国家自然科学基金项目(31460559) 广西自然科学基金项目(2014GXNSFBA118113)
【分类号】：Q953

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