基于简化基因组测序的麋鹿遗传资源多样性及种群结构分析

Genetic Resources Diversity and Population Structure Analysis of Père David's Deer Based on Simplified Genome Sequencing

奠基者效应会打破种群遗传结构,使原有种群动态特征失去平衡,加剧遗传多样性的丧失,严重影响物种重引入的遗传多样性和遗传结构。中国麋鹿(Elaphurus davidianus)奠基种群为北京南海子麋鹿苑和江苏大丰麋鹿国家级自然保护区两大种群。为分析中国麋鹿奠基者效应,探究资源遗传多样性及种群结构,揭示中国麋鹿适应环境的遗传机制,以中国两大麋鹿奠基种群为研究对象,基于简化基因组测序,研究北京和江苏2个地区麋鹿的遗传多样性、种群遗传结构及亲缘关系。结果表明:2个种群(18只)共筛选出高质量多态性SNP位点1456457个;北京麋鹿苑、江苏大丰的麋鹿观测杂合度分别为0.59~0.68和0.63~0.71;北京麋鹿苑的麋鹿遗传多样性略低于江苏大丰,奠基者效应导致2个种群的遗传多样性水平较低,且对于不同重引入种群的影响也不相同。通过SNP标记对北京麋鹿苑与江苏大丰2个麋鹿种群进行遗传分化分析,发现2个种群间平均FST为0.085,表明2个种群间存在中等程度的遗传分化。经neighbor-joining系统发育树和遗传结构分析,进一步验证北京麋鹿苑与江苏大丰的麋鹿已有初步分化的现象,推测可能是2个地区奠基者的遗传差异经随机漂变导致。

The founder effect will break the genetic structure of the population,make the original dynamic characteristics of the population out of balance,aggravate the loss of genetic diversity,and seriously affect the genetic diversity and genetic structure of species reintroduction.The foundation populations of Chinese Père David's deer(Elaphurus davidianus) are at Beijing Nanhaizi Milu Park and Jiangsu Dafeng Milu National Nature Reserve.In order to analyze the founder effect of Père David's deer,explore its genetic diversity and population structure,and reveal the genetic mechanism of Chinese Père David's deer adapting to environment,reduced-representation genome sequencing(RRGS) was used analysis genetic diversity and population structure for 18 individuals from Beijing and Jiangsu regions.Results showed that a total of 1,456,457SNPs were detected with high-quality genomic sequencing.Moreover,observed heterozygosity ranged from 0.59 to 0.68in Beijing population and was from 0.63 to 0.71 in Jiangsu population.The result revealed that the genetic diversity in Beijing population was lower than in Jiangsu population.It revealed that reintroduction lead to lower diversity for Père David's deer populations,and affected genetic mechanism of Père David's deer population adaptation to different environments.In addition,our analysis showed that differentiation in the two populations which was revealed by FST value that was 0.085.And the neighbor-joining phylogenetic tree showed two branches for these two populations.We speculated that the difference of the populations were induced by two factors that genetic difference of founder during reintroduction,and the genetic drift.