Distinct lineages of Schistocephalus parasites in threespine and ninespine stickleback hosts revealed by DNA sequence analysis.
Distinct lineages of Schistocephalus parasites in threespine and ninespine stickleback hosts revealed by DNA sequence analysis.
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DOI：
10.1371/journal.pone.0022505
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发表时间：
2011
期刊：
影响因子：
3.7
通讯作者：
Cresko WA
中科院分区：
文献类型：
--
作者：
Nishimura N;Heins DC;Andersen RO;Barber I;Cresko WA
寄生相互作用通常是生物群落中进化出的复杂种间关系网络的一部分。尽管人们对寄生进化进行了多年的研究，但寄生的姐妹类群能够与宿主共同进化，特异性地感染两个相关谱系的可能性仍然不清楚，即使这些宿主是同属的。此外，当这些特异性相互作用发生时，这种特异性的分子和生理基础在很大程度上仍然未知。这些特定寄生关系的存在现在可以使用DNA序列变异等分子标记进行测试。在这里，我们测试特定的寄生关系在一个新兴的宿主-寄生虫模型，棘鱼-头血吸虫系统。三棘和九棘棘鱼是猪头棘寄生虫的中间宿主，它们在表型上非常相似，并且通过浮游生物、棘鱼和鸟类宿主具有几乎相同的生命周期。我们分析了来自北半球不同地理区域的三棘棘鱼和九棘棘鱼宿主的48个头棘鱼个体的2000多个COX1和NADH1线粒体DNA序列。我们的数据有力地支持了头棘属的两个不同分支的存在，每一个分支都只感染三棘或九棘棘棘鱼。这些分支很可能代表了不同的物种，在它们的棘鱼宿主物种形成后不久就分化了。此外，从阿拉斯加、俄勒冈和威尔士的三棘棘鱼宿主身上提取的头棘鱼也存在遗传结构，尽管这种差异远小于宿主之间的差异。我们的研究结果强调，生物群落可能比它们最初出现的更复杂，并提出了维持头血吸虫寄生虫及其棘鱼宿主特异性的生态、生理和遗传因素的问题。
Parasitic interactions are often part of complex networks of interspecific relationships that have evolved in biological communities. Despite many years of work on the evolution of parasitism, the likelihood that sister taxa of parasites can co-evolve with their hosts to specifically infect two related lineages, even when those hosts occur sympatrically, is still unclear. Furthermore, when these specific interactions occur, the molecular and physiological basis of this specificity is still largely unknown. The presence of these specific parasitic relationships can now be tested using molecular markers such as DNA sequence variation. Here we test for specific parasitic relationships in an emerging host-parasite model, the stickleback-Schistocephalus system. Threespine and ninespine stickleback fish are intermediate hosts for Schistocephalus cestode parasites that are phenotypically very similar and have nearly identical life cycles through plankton, stickleback, and avian hosts. We analyzed over 2000 base pairs of COX1 and NADH1 mitochondrial DNA sequences in 48 Schistocephalus individuals collected from threespine and ninespine stickleback hosts from disparate geographic regions distributed across the Northern Hemisphere. Our data strongly support the presence of two distinct clades of Schistocephalus, each of which exclusively infects either threespine or ninespine stickleback. These clades most likely represent different species that diverged soon after the speciation of their stickleback hosts. In addition, genetic structuring exists among Schistocephalus taken from threespine stickleback hosts from Alaska, Oregon and Wales, although it is much less than the divergence between hosts. Our findings emphasize that biological communities may be even more complex than they first appear, and beg the question of what are the ecological, physiological, and genetic factors that maintain the specificity of the Schistocephalus parasites and their stickleback hosts.
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影响因子：
3.3
作者：
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通讯作者：
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