Landscape genetics: the correlation of spatial and genetic distances of Oncomelania hupensis, the intermediate host snail of Schistosoma japonicum in mainland China
Landscape genetics: the correlation of spatial and genetic distances of Oncomelania hupensis, the intermediate host snail of Schistosoma japonicum in mainland China
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DOI：
10.4081/gh.2009.222
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发表时间：
2009-05-01
影响因子：
1.7
通讯作者：
Zhou, Xiao-Nong
中科院分区：
文献类型：
--
作者：
Li, Shi-Zhu;Wang, Yi-Xiu;Zhou, Xiao-Nong
本文对中国大陆日本血吸虫中间宿主湖北钉螺（Oncomelianihupensis）rDNA非编码区的两个内转录间隔区（ITS 1和ITS 2）和mtDNA的一个16 S RNA基因片段进行了研究，旨在阐明环境对遗传分化的影响。13个居群O.本研究收集了四种不同生态环境的湖北钉螺，比较其遗传距离和空间距离。ITS 1 -5. 8 S-ITS 2基因序列的长度为752 ~ 796 bp，鸟嘌呤-胞嘧啶（GC）含量为49.1- 50.3%，16 S基因序列的长度为505 ~ 508 bp，GC含量为33.5- 35.1%。-5.8S片段显示高度保守，因此在随后的分析中将其去除。而ITS侧翼序列和16 S片段的多态性分别为13.2%和8.6%，可用于进一步研究。遗传关系进行了调查，使用工具的基础上最大的简约，最小的进化和邻居加入算法。O.在16 S系统发育树中，湖北种具有明显的代表性，即（i）山地种群（来自四川和云南省）;（ii）喀斯特地区人口（来自广西自治区）;（iii）代表长江流域（流经安徽、湖南、湖北、江西、江苏及浙江等省）沿着沼泽及湖泊地区的人口;（iv）沿岸的、丘陵地区种群（来自福建省）。根据景观生态学将遗传分化归因于生态特征差异的观点，发现这四个种群分支与环境特征相关。然而，在ITS 1-ITS 2系统发育树中，只发现了三个主要分支。长江流域的沼泽湖泊种群和福建省的沿岸的丘陵种群聚为第三分支。这两个种群在空间上没有联系，即它们之间没有明确的遗传分界。因此，福建种群似乎不构成属于第三分支的单独分支柄。这一事实，以及强有力的遗传证据表明，亚种O。hupensisguangxiensis代表一个离散的分支，支持O.中国大陆湖北省的景观生态学是其最终的结构。
Two internal transcribed spacer (ITS1 and ITS2) sequences Of the non-coding region Of the rDNA and a 16S RNA gene fragment of the mtDNA of Oncomelania hupensis, the intermediate host snail of Schistosoma japonicum in mainland China, have been investigated with a view to illustrate the influence Of the environment Oil genetic differentiation. Thirteen populations of O. hupensis snails, representing four types of ecological settings, were collected to compare genetic and spatial distances. The length of the ITS1-5.8S-ITS2 gene sequence showed a range from 752 to 796 bp with a guanine-cytosine (GC) content of 49.1-50.3%, while that of the 16S sequence ranged from 505 to 508 bp with a GC content Of 33.5-35.1%. The -5.8S fragment was shown to he highly conserved and it was therefore removed in the subsequent analysis. In contrast, the ITS flanking sequences and the 16S fragment were found useful for further study as their degree of polymorphism amounted to 13.2%, and 8.6%, respectively. The genetic relationship was investigated using tools based on maximum parsimony, minimum evolution and neighbour-joining algorithms. Four branches of O. hupensis were found to be clearly represented oil the 16S phylogenetic tree, namely (i) the mountainous region population (from Sichuan and Yunnan provinces); (ii) the Karst region population (from Guangxi autanomous region); (iii) the population representing the region of swamps and lakes along the Yangtze River basin which stretches through the Anhui, Hunan, Hubei, Jiangxi, Jiangsu and Zhejiang provinces; and (iv) the littoral, hilly region population (from Fujian province). These four population branches were found to he correlated to environmental features based on the concept of landscape ecology attributing genetic differentiation to differences ill ecological features. However, only three main branches could be found oil the ITS1-ITS2 phylogenetic tree. The swamps and lakes population (from the Yangtze River basin) and the littoral, hilly population (from Fujian province) were clustered oil the third branch ill Spite Of these two populations not being spatially, related, i.e. no firm genetic demarcation between their snail populations was found. Thus, it seems that the Fujian population does not constitute a separate branch hilt belongs to the third branch. This fact, together with the strong genetic evidence that the sub-species O. hupensis guangxiensis represents a discrete branch, support the hypothesis that genetic differentiation of O. hupensis ill mainland China is ultimately structured by landscape ecology.