Divergent resistance to a monogenean flatworm among three-spined stickleback populations
Divergent resistance to a monogenean flatworm among three-spined stickleback populations
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DOI：
10.1111/j.1365-2435.2010.01775.x
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发表时间：
2011-02-01
影响因子：
5.2
通讯作者：
MacColl, Andrew D. C.
中科院分区：
文献类型：
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作者：
de Roij, Job;Harris, Philip D.;MacColl, Andrew D. C.
P>；1.考虑到寄生虫的普遍存在，我们可能会期待寄生虫在宿主种群的适应性分化中发挥重要作用。具体地说，对当地寄生虫群落的适应被预测会影响一些宿主特征的进化，如寄生虫抵抗力。为了研究不同寄生虫介导的选择在群体水平上驱动寄生虫抗性变异的可能性，我们用单殖扁虫Gyrodactylus gasterbone人工感染实验室饲养的三刺鱼。这些鱼来自苏格兰北乌斯特的五个种群，之所以选择这些种群，是因为它们对弧旋毛虫的自然感染水平不同。我们发现，不同人群对胃肠炎的抵抗力存在很大差异。抗性在很大程度上是由限制蠕虫种群大小的能力定义的，而不是由宿主反应的时间定义的。实验抗性与弧形姬鼠的自然感染水平无显著相关性。然而，总的来说，暴露于弧形线虫较多的种群显示出对弧形线虫的抵抗力更强。来自自然非暴露种群的鱼显示出最高的敏感性，这可能是为了保持抵抗力而进行的较少选择的结果。综上所述，这些结果表明，Gyrodactylus介导的分化选择可能在推动种群水平上对该寄生虫的抗性变异中发挥作用。
P>1. Given their ubiquity, we might expect parasites to play an important role in the adaptive divergence of host populations. Specifically, adaptation to local parasite communities is predicted to influence the evolution of a number of host traits such as parasite resistance.2. To investigate the possibility that divergent parasite-mediated selection drives population-level variation in parasite resistance, we artificially infected lab-reared three-spined sticklebacks with the monogenean flatworm Gyrodactylus gasterostei. The fish were derived from five populations from North Uist, Scotland, that were chosen because they differed in natural infection levels of Gyrodactylus arcuatus.3. We found substantial differences in resistance to G. gasterostei among populations. Resistance was defined largely by the ability to limit the size of the worm population rather than by the timing of the host response.4. Experimental resistance was not significantly correlated with natural infection levels of G. arcuatus. However, in general, populations with greater exposure to G. arcuatus were shown to be more resistant to G. gasterostei. Fish from the only naturally unexposed population showed the highest susceptibility, which may be the result of less selection to maintain resistance.5. Taken together, these results suggest that the divergent selection mediated by Gyrodactylus may play a role in driving population-level variation in resistance to this parasite.