Data from: Plasmodium infection brings forward mosquito oviposition

Invertebrate hosts often bring forward their reproductive effort in response to a parasitic infection. This is widely interpreted as a host-driven response aimed at compensating for the expected losses in future fitness as a result of parasitism. Here we report that mosquitoes bring forward their oviposition schedule when they are infected with Plasmodium, a parasite known to severely curtail mosquito fecundity. This response could aim at compensating for a negative time-dependent effect of the parasite on mosquito fitness, as infected mosquitoes seem to display a strong and progressive decrease in the quality of the eggs they lay. In addition, we show that this shift in oviposition date is dependent on mosquito strain: a comparison of several isogenic mosquitoes strains, one insecticide-susceptible and two insecticide-resistant ones, reveals that only the former shift their oviposition strategy when infected. This pattern suggests the existence of a costly host-driven response to parasitism, as insecticide-resistant mosquitoes have been shown to be in generally poorer condition.

无脊椎动物宿主在遭受寄生虫感染时，往往会提前启动繁殖投入。这一现象通常被解读为宿主驱动的适应性响应，旨在弥补寄生虫感染所导致的未来适合度（fitness）预期损失。本研究发现，蚊子感染疟原虫（Plasmodium）后会提前其产卵节律；而疟原虫是一种已知会严重削弱蚊子繁殖力的寄生虫。该响应或可弥补寄生虫对蚊子适合度产生的时间依赖性负面影响——受感染蚊子所产虫卵的质量会呈现显著且渐进式的下降。此外，本研究证实，产卵节律的提前与否取决于蚊子品系：通过对三株同基因蚊子品系的对比分析（1株为杀虫剂敏感型，2株为抗杀虫剂型），结果显示仅杀虫剂敏感型品系的蚊子在感染后会调整其产卵策略。这一模式表明，宿主针对寄生虫感染的主动响应存在进化代价，因为已有研究证实，抗杀虫剂型蚊子的整体健康状况通常较差。