Department of Zoology, University of Oxford, Oxford, United Kingdom.
Department of Microbiology, University of Tennessee, Knoxville, TN, United States of America.
PLoS One. 2020 Nov 18;15(11):e0242159. doi: 10.1371/journal.pone.0242159. eCollection 2020.
Evolutionary interactions between parasitoid wasps and insect hosts have been well studied at the organismal level, but little is known about the molecular mechanisms that insects use to resist wasp parasitism. Here we study the interaction between a braconid wasp (Aphidius ervi) and its pea aphid host (Acyrthosiphon pisum). We first identify variation in resistance to wasp parasitism that can be attributed to aphid genotype. We then use transcriptome sequencing to identify genes in the aphid genome that are differentially expressed at an early stage of parasitism, and we compare these patterns in highly resistant and susceptible aphid host lines. We find that resistant genotypes are upregulating genes involved in carbohydrate metabolism and several key innate immune system genes in response to parasitism, but that this response seems to be weaker in susceptible aphid genotypes. Together, our results provide a first look into the complex molecular mechanisms that underlie aphid resistance to wasp parasitism and contribute to a broader understanding of how resistance mechanisms evolve in natural populations.
寄生蜂与昆虫宿主之间的进化相互作用在机体水平上已经得到了很好的研究，但对于昆虫用来抵抗寄生蜂寄生的分子机制知之甚少。在这里，我们研究了一种茧蜂（Aphidius ervi）与其豌豆蚜宿主（Acyrthosiphon pisum）之间的相互作用。我们首先确定了对寄生蜂的抗性的变化，可以归因于蚜虫的基因型。然后，我们使用转录组测序来鉴定在寄生早期在蚜虫基因组中差异表达的基因，并比较高抗性和易感性蚜虫宿主系中的这些模式。我们发现，抗性基因型上调了与碳水化合物代谢和几个关键先天免疫系统基因相关的基因，以应对寄生，但在易感性蚜虫基因型中，这种反应似乎较弱。总之，我们的研究结果首次揭示了蚜虫抵抗寄生蜂寄生的复杂分子机制，并有助于更广泛地了解抗性机制在自然种群中的进化方式。
