Host life history and host-parasite syntopy predict behavioural resistance and tolerance of parasites.
Host life history and host-parasite syntopy predict behavioural resistance and tolerance of parasites.
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宿主生活史和宿主-寄生虫同源性预测寄生虫的行为抵抗力和耐受性。
DOI：
10.1111/1365-2656.12333
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
Rohr,JasonR
中科院分区：
文献类型：
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作者：
Sears,BrittanyF;Snyder,PaulW;Rohr,JasonR
越来越多的人对宿主的生活史特征（如它们的“生活节奏”）在对寄生虫的抗性和耐受性的进化中所起的作用感兴趣。理论表明，相对于具有高同源性的宿主物种，（局部空间和时间重叠）与寄生虫，低共构的宿主物种应该有较低的选择压力，（总是存在的）和昂贵的防御措施，如容忍，以及更多地依赖更容易诱导和更便宜的防御措施，如行为。因此，我们假设宿主-寄生虫共体的程度与宿主的生活节奏呈负相关，（反映蝌蚪的发育速度和变态时大小的倒数的轴）（吸虫）系统，将分别是行为抗性和耐受性的负和正预测因子。为了检验这些假设，我们将七种蝌蚪暴露于一系列寄生虫（尾蚴）剂量，并与控制抗寄生虫行为的麻醉治疗交叉。我们量化了宿主行为、成功和不成功的感染，以及每个物种对行为抗性和耐受性的反应标准，分别定义为尾蚴暴露（或尝试感染）与抗尾蚴行为和质量变化之间的斜率。因此，耐受性是捕获寄生虫暴露的任何成本。正如假设的那样，蝌蚪的生活节奏是行为抗性的显著正预测因子和耐受性的负预测因子，这一结果与跨物种的行为抗性和耐受性之间的权衡一致，值得进一步研究。此外，这些结果对寄生虫发生、三种最快或最慢节奏物种的所有可能的重新排序以及各种耐受性测量的考虑都是稳健的。这些结果表明，宿主的生活节奏和宿主-寄生虫的共生性是宿主防御寄生虫策略的强度和类型的强大驱动力。未来的研究应该评估宿主的生活节奏和宿主-寄生虫的共构关系的频率和强度，以及哪一种是抗寄生虫防御中宿主投资的强度和类型的更好预测因子。
There is growing interest in the role that life‐history traits of hosts, such as their ‘pace‐of‐life’, play in the evolution of resistance and tolerance to parasites.Theory suggests that, relative to host species that have high syntopy (local spatial and temporal overlap) with parasites, host species with low syntopy should have lower selection pressures for more constitutive (always present) and costly defences, such as tolerance, and greater reliance on more inducible and cheaper defences, such as behaviour. Consequently, we postulated that the degree of host–parasite syntopy, which is negatively correlated with host pace‐of‐life (an axis reflecting the developmental rate of tadpoles and the inverse of their size at metamorphosis) in our tadpole–parasitic cercarial (trematode) system, would be a negative and positive predictor of behavioural resistance and tolerance, respectively.To test these hypotheses, we exposed seven tadpole species to a range of parasite (cercarial) doses crossed with anaesthesia treatments that controlled for anti‐parasite behaviour. We quantified host behaviour, successful and unsuccessful infections, and each species’ reaction norm for behavioural resistance and tolerance, defined as the slope between cercarial exposure (or attempted infections) and anti‐cercarial behaviours and mass change, respectively. Hence, tolerance is capturing any cost of parasite exposure.As hypothesized, tadpole pace‐of‐life was a significant positive predictor of behavioural resistance and negative predictor of tolerance, a result that is consistent with a trade‐off between behavioural resistance and tolerance across species that warrants further investigation. Moreover, these results were robust to considerations of phylogeny, all possible re‐orderings of the three fastest or slowest paced species, and various measurements of tolerance.These results suggest that host pace‐of‐life and host–parasite syntopy are powerful drivers of both the strength and type of host defence strategies against parasites. Future research should evaluate how often and how strongly host pace‐of‐life and host–parasite syntopy are correlated and which is the better predictor of the strength and type of host investments in anti‐parasite defences.