Data from: Heritable variation in an extended phenotype: the case of a parasitoid manipulated by a virus

In host-symbiont interactions, the genes of both host and symbiont can influence phenotypic traits. In the context of a conflict of interest, fitness-related traits are subjected to opposing selective pressures in the genomes of the partners. In the Drosophila parasitoid Leptopilina boulardi, females usually avoid laying eggs into already parasitized larvae. However, when infected by the virus LbFV, they readily lay additional eggs into parasitized larvae. Inducing superparasitism allows the virus to colonize uninfected parasitoid lineages, but is usually mal-adaptive for the parasitoid. We tested for the presence of resistance genes to this behavioural manipulation in the parasitoid genotype by sampling 30 lines from 5 populations with contrasting viral prevalence, after infecting them with a reference viral isolate. No geographical differentiation was observed although some genotypes underwent less manipulation than others and these differences were heritable across generations. The viral titre was not correlated to these differences, although fecundity differed between extreme lines.

在宿主-共生体互作（host-symbiont interactions）中，宿主与共生体的基因均可调控表型性状（phenotypic traits）。当双方存在利益冲突时，与适合度相关的性状会在二者的基因组中受到相反的选择压力作用。以果蝇寄生蜂Leptopilina boulardi为研究对象，其雌蜂通常会避免在已被寄生的果蝇幼虫体内产卵，但当雌蜂感染病毒LbFV后，便会轻易地在已寄生的幼虫体内额外产卵。诱导过寄生（superparasitism）可使病毒定植于未感染的寄生蜂谱系中，但通常对该寄生蜂自身存在适应不良的影响。本研究通过从5个病毒流行率存在显著差异的种群中采集30个品系，并用参考病毒分离株（viral isolate）对这些品系进行感染，以此检测寄生蜂基因型中是否存在针对这种行为操控的抗性基因。结果显示，尽管部分基因型的行为操控程度低于其他基因型，且这些差异在世代间具有可遗传性，但未观察到地理分化（geographical differentiation）现象。病毒滴度（viral titre）与这些行为差异并无关联，尽管极端品系间的繁殖力（fecundity）存在差异。