Hudson A I, Fleming-Davies A E, Páez D J, Dwyer G
Department of Ecology and Evolution, University of Chicago, Chicago, IL, USA.
J Evol Biol. 2016 Dec;29(12):2480-2490. doi: 10.1111/jeb.12977. Epub 2016 Sep 29.
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.
基因型与基因型（G×G）相互作用是宿主与寄生虫协同进化的必要条件，但仅在少数动物模型系统中得到证实。G×G效应源于宿主和病原体基因型之间的相互作用，因此某些病原体菌株在某些宿主中更具传染性，而某些宿主对某些病原体菌株更易感。我们测试了舞毒蛾（Lymantria dispar）及其杆状病毒中的G×G相互作用。我们用16种杆状病毒分离株分别感染了21个舞毒蛾全同胞家系，并测量了所有分离株两两组合的宿主家系间感染率的分离株间相关性。分离株之间的平均传染性不同，宿主家系之间的疾病易感性也不同。感染率的分离株间相关性通常小于1，表明宿主和病原体类型的非加性效应，这与G×G相互作用一致。我们的结果支持舞毒蛾-杆状病毒相互作用中存在G×G效应，并提供了经验证据，即田间采集的分离株之间感染率的相关性与数学模型先前显示的增加病原体多态性可能性的值一致。
