Data from: Genotype-by-genotype interactions between an insect and its pathogen

Genotype-by-genotype (G×G) interactions are an essential requirement for the coevolution of hosts and parasites, but have only been documented in a small number of animal model systems. G×G effects arise from interactions between host and pathogen genotypes, such that some pathogen strains are more infectious in certain hosts and some hosts are more susceptible to certain pathogen strains. We tested for G×G interactions in the gypsy moth (Lymantria dispar) and its baculovirus. We infected 21 full-sib families of gypsy moths with each of 16 isolates of baculovirus and measured the between-isolate correlations of infection rate across host families for all pairwise combinations of isolates. Mean infectiousness varied among isolates and disease susceptibility varied among host families. Between-isolate correlations of infection rate were generally less than one, indicating nonadditive effects of host and pathogen type consistent with G×G interactions. Our results support the presence of G×G effects in the gypsy moth–baculovirus interaction and provide empirical evidence that correlations in infection rates between field-collected isolates are consistent with values that mathematical models have previously shown to increase the likelihood of pathogen polymorphism.

基因型-基因型（Genotype-by-genotype, G×G）互作是宿主与寄生虫协同演化的必要条件，但目前仅在少量动物模型系统中被报道。G×G效应源于宿主与病原体基因型之间的互作，即部分病原体菌株在特定宿主中传染性更强，而部分宿主对特定病原体菌株更易感。我们在舞毒蛾（Lymantria dispar）及其杆状病毒（baculovirus）体系中检测了G×G互作：使用16株杆状病毒分别感染21个舞毒蛾全同胞家系，并针对所有病毒株两两组合，测量了各病毒株在不同宿主家系间的感染率相关性。实验结果显示，不同病毒株的平均感染力存在差异，不同宿主家系的疾病易感性也存在差异；病毒株间的感染率相关性普遍小于1，表明宿主与病原体类型存在非加性效应，这与G×G互作的特征相符。本研究结果证实了舞毒蛾-杆状病毒互作体系中存在G×G效应，并提供了实验证据，表明野外采集的病毒分离株之间的感染率相关性，符合数学模型此前提出的可提升病原体多态性发生概率的数值特征。