中国部分区域黄胸鼠种群遗传学研究

发布时间：2018-01-01 10:35

本文关键词：中国部分区域黄胸鼠种群遗传学研究　出处：《中国疾病预防控制中心》2012年硕士论文　论文类型：学位论文

【摘要】：黄胸鼠(Rattus tanezumi)主要分布于东亚和东南亚的低纬度地区。在中国,黄胸鼠是主要家栖鼠种之一,以前主要分布于长江流域及以南地区,近年来黄胸鼠分布区域有所扩大,西至青海省、西藏自治区和新疆维吾尔自治区,北至河北省和辽宁省均有分布。黄胸鼠对房舍区的危害较重,而且其体表携带有多种寄生虫,是许多细菌、立克次体和滤过性病毒的储存宿主,传播的重要传染病有鼠疫、钩端螺旋体病、地方性斑疹伤寒和肾综合征出血热等。黄胸鼠分布范围的扩大会给人类健康带来新的威胁。我们对于中国的黄胸鼠进行种群遗传学研究,可以更深入地认识黄胸鼠的相关生态学特点,为黄胸鼠的种群监测和防控提供理论依据。本研究运用线粒体DNA和微卫星序列两种不同的分子遗传标记对于中国境内的25个黄胸鼠种群的遗传多样性、遗传结构和迁移等方面进行研究,其结果如下： (1)以磁珠富集法构建了黄胸鼠微卫星富集文库,共筛选出黄胸鼠微卫星引物13对。用这13对引物对于上海市普陀区和重庆市万州区标本中挑选出的50个样本进行扩增,结果显示所有的微卫星位点均呈现高多态性,而且均偏离了哈迪-温伯格平衡,种群呈现杂合子不足状态,但没有发现任何两个位点存在连锁不平衡。成功筛选出的这些微卫星引物对于黄胸鼠以及本属其他物种的种群遗传学研究有着重要意义。 (2)线粒体DNA和微卫星序列数据共同表明不同地理区域的黄胸鼠种群遗传多样性差异较大。COI序列黄胸鼠种群的单倍型多样性(Hd)为0.06061～0.79234,核苷酸多样性(π)为0.00009-0.00532；D-loop序列种群的单倍型多样性(Hd)为0.10000～0.88424,核苷酸多样性(π)为0.00024～0.02165；微卫星数据的种群观察杂合度(Ho)为0.497～0.708,期望杂合度(He)为0.656～0.890,种群的等位基因数为5.15～15.15。云贵高原的种群表现出比较高的遗传多样性,而且遗传分化也比较明显。 (3)线粒体DNA和微卫星序列这两个遗传标记对于不同地理区域黄胸鼠种群的研究结果表明,自然环境对于黄胸鼠种群结构的连续性产生明显影响。云贵高原复杂的地理环境对于黄胸鼠的基因流产生明显在阻隔作用,青藏高原也呈现一定的阻隔效应,但是琼州海峡由于形成时间较晚,交通往来相对便利,并没有对黄胸鼠的基因交流表现出影响。在种群遗传距离和地理距离关系的研究中,二者几乎无相关性,黄胸鼠的基因交流模式更加倾向于海岛模型。 (4)通过这两个遗传标记的种群遗传距离及系统进化树研究表明,西藏拉萨和林芝地区的黄胸鼠与四川和重庆等地的黄胸鼠关系更近,极有可能通过川藏公路发生迁移；而北方如石家庄的黄胸鼠则与长江流域黄胸鼠亲缘关系更近,很可能通过华中地区的京广铁路等重要交通线路向北方传播。云贵高原的黄胸鼠与其他地区的黄胸鼠分化比较明显,但是在雷州和义乌出现了与云贵地区存在紧密遗传关系的单倍型,说明云贵高原的黄胸鼠可能通过某些因素向上述区域迁移,也提示云贵高原的黄胸鼠与上述曾经发生鼠疫的地区存在某种内在关联。 (5)微卫星序列的研究结果和线粒体DNA的研究结果并不完全吻合,如在种群配对FST值(遗传分化系数)上存在一些差异,这也进一步说明只用综合运用不同的分子标记进行分析,才能更为准确和有效地对物种种群遗传情况作出评价。本文运用了线粒体DNA和微卫星序列两种不同的分子标记分析了中国黄胸鼠种群的遗传特征和地理分布的关系,为进一步研究该物种与人类健康的关系奠定了基础。
[Abstract]:Rattus norvegicus is mainly distributed in the low latitude region of East Asia and Southeast Asia . In China , the yellow chest mouse is one of the main species of the dominant species , which has been mainly distributed in the Yangtze River valley and the south of the Yangtze River . In recent years , the distribution area of the yellow chest mouse has been enlarged , and its body surface carries many parasites . It is a major infectious disease with plague , leptospirosis , endemic typhus and hemorrhagic fever of kidney syndrome . In this study , the genetic diversity , genetic structure and migration of 25 yellow chest mouse populations in China were studied by using two different molecular genetic markers of mitochondrial DNA and microsatellite sequences . The results were as follows : ( 1 ) The microsatellite enrichment library of Rattus pectus was constructed by magnetic bead enrichment method , and 13 pairs of microsatellite primers were screened . The results showed that all the microsatellite loci were highly polymorphic , and all the microsatellite loci were deviated from Hardy - Wemberger ' s equilibrium , and the population presented a heterozygous deficiency , but no linkage disequilibrium was found in any two sites . The microsatellite primers successfully screened were of great significance for the study of the population genetics of Rattus flavobotus and other species of the genus . ( 2 ) The mitochondrial DNA and microsatellite sequence data show that the diversity of the population genetic diversity is larger in different geographical regions . The haplotype diversity ( Hd ) of the population of the COI sequence is 0.06061 - 0.79234 , the nucleotide diversity ( . pi . ) is 0.000001 - 0.00532 , the diversity of the nucleotide diversity ( Hd ) is 0.497 - 0.88424 , the number of alleles of the population is 5.15 - 15.15 . The population of the Yunnan - Guizhou Plateau shows relatively high genetic diversity , and the genetic differentiation is also obvious . ( 3 ) These two genetic markers of mitochondrial DNA and microsatellite sequences have a significant impact on the continuity of the population structure of the yellow chest mouse . The complex geographic environment of the Yungui Plateau has a clear effect on the gene flow of the yellow chest mouse . However , since the formation time is relatively late , the traffic flow is relatively convenient . In the study of the relationship between the population genetic distance and the geographical distance , there is little correlation between the two genes , and the gene communication mode of the yellow chest mouse is more inclined to the island model . ( 4 ) The population genetic distance and phylogenetic tree study of these two genetic markers indicate that the yellow chest mouse in Lhasa and Linzhi area of Tibet is closer to the yellow chest mouse in Sichuan and Chongqing , and it is likely to spread to the north through important traffic lines such as Sichuan and Chongqing . The yellow chest mouse in the north , such as Shijiazhuang , is more closely related to the yellow chest mouse in the Yangtze River valley . ( 5 ) The results of the study of microsatellite sequences and the results of the study of mitochondrial DNA were not completely consistent , such as there were some differences in the population - pair , but also with different molecular markers , in order to more accurately and effectively evaluate the genetic condition of species populations . In this paper , two different molecular markers of mitochondrial DNA and microsatellite sequences were used to analyze the relationship between the genetic characters and geographical distribution of the population in China , which laid the foundation for further research on the relationship between the species and human health .

【学位授予单位】：中国疾病预防控制中心
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R394;Q953

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