Extending the ecology of fear: Parasite-mediated sexual selection drives host response to parasites
Extending the ecology of fear: Parasite-mediated sexual selection drives host response to parasites
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DOI：
10.1016/j.physbeh.2020.113041
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发表时间：
2020-10-01
影响因子：
2.9
通讯作者：
Luong, Lien T.
中科院分区：
文献类型：
--
作者：
Horn, Collin J.;Mierzejewski, Monika K.;Luong, Lien T.
“恐惧生态”描述了天敌对潜在受害者的负面影响，即使这些受害者没有被消费或感染。虽然最近的研究表明寄生虫对潜在宿主具有非消耗性影响(NCE)，但这些影响在宿主群体中如何变化还不是很清楚。我们通过测量暴露于体外寄生虫Macrocheles subbadius的幼龄黑腹果蝇的代谢率(MR)，研究了NCE如何基于宿主感染风险和相对感染成本的变化。我们测试了两个相互排斥的假设：1)感染成本不对称驱动适应，以获得对寄生虫暴露的更强反应；或2)感染风险不对称，驱动适应，以对寄生虫暴露做出更强反应。在这个系统中，由于寄生虫性选择，雄性果蝇比雌性果蝇有更高的感染成本；同样，处女果蝇比交配的雌性果蝇经历更高的感染成本。不同果蝇感染的风险也不同，因为螨类优先感染雌性果蝇而不是雄性果蝇，而蠕虫则优先感染交配的雌性果蝇而不是处女果蝇。我们的结果与感染成本驱动对尘螨风险的反应强度的假设是一致的。雌性果蝇对寄生虫暴露的反应是MR增加了15.1%，而暴露于寄生虫暴露的雄性果蝇表现出了更强的反应，MR增加了31.3%，交配的雌性果蝇在寄生期间增加了34.8%，而处女雌性果蝇的MR增加了61.2%。我们的发现表明，寄生虫的NCE可能会因国家感染成本的不同而不同。
The 'ecology of fear' describes the negative effects natural enemies have on potential victims even when those victims are not consumed or infected. Although recent work has demonstrated parasites have non-consumptive effects (NCE) on potential hosts, how these effects vary within host populations is not well understood. We investigated how NCE vary based on host risk of infection and relative cost of infection by measuring the metabolic rate (MR) of naive Drosophila nigrospiracula exposed to an ectoparasite, Macrocheles subbadius. We tested two mutually exclusive hypotheses: 1) asymmetrical costs of infection drive adaptions for stronger responses to parasite exposure; or 2) asymmetrical risks of infection drive adaptions for stronger responses to parasite exposure. In this system, male flies have higher costs of infection relative to female flies due to parasitemediated sexual selection; similarly, virgin females experience higher costs of infection relative to mated females. Risk of infection also varies among flies because mites preferentially infect female flies over males, and mites preferentially infect mated females over virgin females. Our results were compatible with the hypothesis that costs of infection drive the strength of response to mite risk. Female flies responded to parasite exposure with a 15.1% increase in MR, while exposed males showed a stronger response with a 31.3% increase in MR. Mated females increased their MR by 34.8% during mite exposure whereas virgin females experienced an increase of 61.2%. Our findings suggest that NCE of parasites can vary based on state-dependent costs of infection.