Rapid evolution and ecological host-parasite dynamics
Rapid evolution and ecological host-parasite dynamics
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DOI：
10.1111/j.1461-0248.2006.00995.x
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发表时间：
2007-01-01
期刊：
影响因子：
8.8
通讯作者：
Sivars-Becker, Lena
中科院分区：
文献类型：
--
作者：
Duffy, Meghan A.;Sivars-Becker, Lena
传统上，寄生虫流行病的终止归因于生态原因：即由于死亡或获得性免疫而导致易感宿主的耗竭。在这里，我们认为流行病也可以因为宿主的快速进化而结束。专注于一个特定的宿主-寄生虫系统，水蚤dentifera和它的寄生虫Metschnikowia bicuspidata，我们表明，水蚤从湖泊最近的流行病更耐感染，并有较少的变化比水蚤从湖泊没有最近的流行病的易感性。然而，我们的研究揭示了Metschnikowia感染性或毒力遗传变异的证据很少。将所观察到的宿主易感性的遗传变异转化为该系统参数化的流行病学模型表明，快速进化可以解释在与湖泊种群中发生的情况相匹配的时间尺度上流行病的终止。因此，我们的研究不仅为自然种群中寄生虫介导的选择提供了罕见的证据，还表明快速进化对短期宿主-寄生虫动态具有重要影响。
Traditionally, the termination of parasite epidemics has been attributed to ecological causes: namely, the depletion of susceptible hosts as a result of mortality or acquired immunity. Here, we suggest that epidemics can also end because of rapid host evolution. Focusing on a particular host-parasite system, Daphnia dentifera and its parasite Metschnikowia bicuspidata, we show that Daphnia from lakes with recent epidemics were more resistant to infection and had less variance in susceptibility than Daphnia from lakes without recent epidemics. However, our studies revealed little evidence for genetic variation in infectivity or virulence in Metschnikowia. Incorporating the observed genetic variation in host susceptibility into an epidemiological model parameterized for this system reveals that rapid evolution can explain the termination of epidemics on time scales matching what occurs in lake populations. Thus, not only does our study provide rare evidence for parasite-mediated selection in natural populations, it also suggests that rapid evolution has important effects on short-term host-parasite dynamics.