Genotype‐by‐genotype interactions between an insect and its pathogen

Abstract

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.

Rift Valley fever virus: strategies for maintenance, survival and vertical transmission in mosquitoes

“…Vector competence relies on the specific interaction between the vector and arbovirus genotypes, termed GÂG (genotype-by-genotype) interactions [113]. Traits such as dissemination, midgut escape barrier and mortality are governed by adaptation by the virus to the vector and vice versa [114][115][116].…”

Creating outbred and inbred populations of haplodiploid mites to measure adaptive responses in the lab

“…Macke et al 2014). Also, the magnitude of GxG (genotype by genotype) in host parasite interactions has been addressed by exposing different lines of hosts and/or parasites to each other (Lambrechts, Fellous and Koella 2006, de Roode and Altizer 2010, Carpenter et al 2012, Hudson et al 2016. Finally, there is a recently increasing interest on how inter-individual variation affects several ecological characteristics, such as species persistence and coexistence (Lichstein et al 2007, Agashe 2009, Lankau 2009, Bolnick et al 2011, Forsman and Wennersten 2016, Hart et al 2016.…”

Covert Infection of Insects by Baculoviruses

“…Genetic variation in baculovirus populations favors horizontal transmission due to heterogeneity in host susceptibility to infection (Hudson et al, 2016) and interactions among virus genotypes that increase OB infectivity and OB production in infected insects (Clavijo et al, 2009; Barrera et al, 2013; Bernal et al, 2013). Indeed, alphabaculovirus ODVs and OBs are genotypically diverse and form collective infectious units that ensure horizontal transmission of multiple viral genotypes (Sanjuán, 2017).…”

“…The role of host phenotype has begun to be examined by rearing siblings from egg masses or using insects such as tent caterpillars which live in sibling groups (families) that can be compared for within-group and between-group susceptibility to lethal infection and sublethal effects (Páez et al, 2015; Hudson et al, 2016; Myers and Cory, 2016). Indeed, susceptibility to nucleopolyhedrovirus varies across families so that the risk of mortality depends on virus isolate and family interactions in gypsy moth ( L. dispar ) larvae (Hudson et al, 2016).…”

“…Indeed, susceptibility to nucleopolyhedrovirus varies across families so that the risk of mortality depends on virus isolate and family interactions in gypsy moth ( L. dispar ) larvae (Hudson et al, 2016). …”