【作者】 成起萱；

【导师】 王成辉；

【作者基本信息】 上海海洋大学 ， 水产养殖， 2011， 硕士

【摘要】 中华绒螯蟹(Eriocheir sinensis)、日本绒螯蟹(Eriocheir japonica),合浦绒螯蟹(Eriocheir hepuensis)是绒螯蟹属的重要经济种类,分布范围广,其中中华绒螯蟹已移居至欧洲的广大地区及北美等。本论文应用微卫星标记,从核基因组对中华绒螯蟹、日本绒螯蟹、合浦绒螯蟹的分子遗传变异和进化进行研究分析,具体研究内容如下:1、日本绒螯蟹、合浦绒螯蟹的微卫星标记开发合浦绒螯蟹分布于我国南部水域,是一种濒临灭绝的淡水蟹。在本论文中我们利用磁珠富集法开发了合浦绒螯蟹的15对微卫星引物,并应用于1998年和2008年合浦绒螯蟹样本的效果评估。结果发现:每个引物的等位基因数为6.3～8.4,观测杂合度为0.725～0.817,期望杂合度为0.756～0.780,多态信息含量为0.699～0.756。近十年来(1998-2008),合浦绒螯蟹出现了显著的遗传分化现象。微卫星标记为合浦绒螯蟹的群体结构和遗传渐渗等方面的研究提供了工具。日本绒螯蟹是东亚所特有的一种产卵顺流而下的物种,它是绒螯蟹属中分布最广的绒螯蟹。目前,关于日本绒螯蟹的微卫星引物还未有报道。本论文中,开发了20对具有较高多态性的日本绒螯蟹微卫星标记,并在中华绒螯蟹长江群体与黄河群体中进行了验证,结果发现4对微卫星引物偏离了哈迪-温伯格平衡,中华绒螯蟹长江群体与黄河群体中等位基因数、等位基因丰富度、基因多样性等数值相近。这些微卫星引物可成功地应用于中华绒螯蟹群体等绒螯蟹属的遗传变异及群体结构研究。2、中华绒螯蟹国内土著群体与海外移居群体的分子遗传变异与适应性进化中华绒螯蟹是中国特有的土著种类,现在已经广泛分布于欧洲和北美地区。本研究利用20对微卫星标记对中华绒螯蟹国内土著种群(长江和黄河)和国外移居群体(德国易北河,荷兰莱茵河,英国泰晤士河和美国旧金山湾)的遗传变异和多样性进行了分析。结果显示,中华绒螯蟹国内、外群体在遗传多样性指标上(如等位基因丰富度、多态信息含量和杂合度等)略高于国外移居群体,国内、外群体间,以及国外不同群体间存在显著的遗传分化;贝叶斯聚类分析显示国内土著群体、欧洲移居群体和美国移居群体分成明显的三个遗传聚类;主成分分析(PCA)也表明了国外移居群体已产生了明显的遗传岐化;荷兰莱茵河群体检测到显著的遗传瓶颈效应。结合海外移居群体中特有的等位基因,表明中华绒螯蟹在海外的入侵过程中已发出了明显的适应性进化。3、中华绒螯蟹与合浦绒螯蟹的遗传变异与渐渗研究中华绒螯蟹与合浦绒螯蟹存在不同的分布域,中华绒螯蟹主要集中在我国长江及以北的水域中,合浦绒螯蟹主要分布于南部水域(珠江、南流江),而瓯江与闽江则是中华绒螯蟹与合浦绒螯蟹的混杂地带。本研究利用6对具有较高多态性的微卫星引物对大陆沿海6个绒螯蟹群体(辽河、黄河、长江、瓯江、闽江和珠江)进行遗传变异与渐渗研究。结果显示中国大陆沿海绒螯蟹群体中,长江中华绒螯蟹群体具有最高的多态性,而珠江绒螯蟹群体的多态性最低,瓯江与闽江群体的多态性基本差不多;除黄河群体和辽河群体之间不存在显著的遗传分化(P=0.351),其他各群体之间遗传分化都显著,在N-J聚类中我们也可以看到黄河群体与辽河群体的遗传距离最近(2.856),最先聚为一支。贝叶斯遗传重排分析显示,浙江瓯江群体与福建闽江群体的绒螯蟹可能存在中华绒螯蟹与合浦绒螯蟹的杂交种,可能存在杂交和遗传渐渗现象。更多还原

【Abstract】 The Chinese mitten crab (Eriocheir sinensis), the Japanese mitten crab (Eriocheir japonica) and the Hepu mitten crab (Eriocheir hepuensis) are important economical species in the mitten crab which have wide distribution in the East Asian. The Chinese mitten crab has been introduced to Europe and North America. In this study, we used microsatellite locus to detect the Genetic variation and adaptive evolution in the Chinese mitten crab、Hepu mitten crab and Japanese mitten crab.1、Microsatellite markers development in the Hepu mitten crab and Japanese mitten crabThe Hepu mitten crab (Eriocheir hepuensis) is an endangered freshwater crab found in the southern part of China. In this study, 15 polymorphic microsatellite loci were isolated and population genetic parameters were evaluated in three populations of E. hepuensis sampled in 1998 and 2008. The average number of alleles per locus ranged from 6.3 to 8.4, while the average observed (HO) and expected (HE) heterozygosities were from 0.725 to 0.817 and from 0.756 to 0.780, respectively. The average polymorphism information content (PIC) ranged from 0.699 to 0.756. Significant genetic differentiation was observed for E. hepuensis in the current decade (from 1998 to 2008). This suite of microsatellite loci will facilitate future studies on population structure and genetic introgression of the endangered E. hepuensis.The Japanese mitten crab (Eriocheir japonica) is a catadromous species endemic to East Asia with the widest distribution of all species in the mitten crab taxonomy. To date, no novel microsatellite loci for this species have been reported. Twenty polymorphic microsatellite loci were isolated, and cross-amplification was conducted in the Yangtze and Yellow River populations of Chinese mitten crab (Eriocheir sinensis). Four loci were found to deviate significantly from the Hardy-Weinberg equilibrium. Similar numbers of alleles, mean observed (HO) and expected (HE) heterozygosities, mean gene diversity, and inbreeding coefficients (FIS) were detected in the two populations of E. sinensis. We concluded that this suite of microsatellite loci was successful for cross-amplification in E. sinensis and might be useful for the assessment of population structure of the mitten crab.2、Genetic variation and adaptive evolution between the native and invasive Chinese mitten crabThe Chinese mitten crab (Eriocheir sinensis), a native species in China, has been introduced to Europe and North America and has posed great influences on invaded ecosystems because of its rapid expansion. In this study, genetic variation and diversity of the Chinese mitten crab between its native habitats (The Yangtze and Yellow Rivers in China) and the invade rivers (the Elbe River in Germany, Rhine River in Netherlands, Thames River in UK and the San Francisco Bay in USA) were investigated using twenty microsatellites loci. The results found the native populations possess higher genetic diversity than the introduced populations, and significant genetic differentiation between the native and invasive populations, and among the invasive populations. Bayesian clustering analysis showed significant genetic cluster of the invasive population from the native rages, and also significant genetic variation between the North American and European populations. Principal component analysis (PCA) indicated the high level of genetic differentiation in invasive populations from the native populations. However, only the Rhine River was detected significant bottleneck sign. A number of private alleles observed in the invasive populations suggested adaptive evolution occurred in colonized process.3、Genetic variation and introgression between the Chinese mitten crab and the Hepu mitten crabThe Chinese mitten crab and the Hepu mitten crab have the different distribution areas, the Chinese mitten crab mainly distributes in the northern part of the Changjiang river (including in Changjiang river), and the Hepu mitten crab distributes in the Zhujiang and Nanliujiang Rivers, while the Oujiang and Minjiang are the dilution zone of the Chinese mitten crab and Hepu mitten crab. In this study, genetic variation and introgression between the Chinese mitten crab and the Hepu mitten crab (Zhujiang) were investigated using six microsatellites loci. The results found the Chinese mitten crab in the Yangtze River had the highest polymorphism information content, while the Hepu mitten crab (ZJ) were the lowest; there were significant genetic differentiation between the pair population comparison with the exception of the Yellow (YR) and Liaohe (LH) Rivers (P=0.351). There was a closest genetic distance between the YR and LH(2.856) based on the NJ tree; Bayesian genetic alignment results indicated that the OJ population and MJ population may have crossed and made genetic introgression between them.更多还原