title: Strong specificity in the interaction between parasitoids and symbiont-protected hosts.
abstract: Coevolution between hosts and parasites may promote the maintenance of genetic variation in both antagonists by negative frequency-dependence if the host-parasite interaction is genotype-specific. Here we tested for specificity in the interaction between parasitoids (Lysiphlebus fabarum) and aphid hosts (Aphis fabae) that are protected by a heritable defensive endosymbiont, the γ-proteobacterium Hamiltonella defensa. Previous studies reported a lack of genotype specificity between unprotected aphids and parasitoids, but suggested that symbiont-conferred resistance might exhibit a higher degree of specificity. Indeed, in addition to ample variation in host resistance as well as parasitoid infectivity, we found a strong aphid clone-by-parasitoid line interaction on the rates of successful parasitism. This genotype specificity appears to be mediated by H. defensa, highlighting the important role that endosymbionts can play in host-parasite coevolution.
authors.affiliation: Institute of Integrative Biology, ETH Zürich, Zürich, Switzerland. romain.rouchet@eawag.ch
authors.forename: Romain
authors.initials: R
authors.lastname: Rouchet
authors.forename: C
authors.initials: C
authors.lastname: Vorburger
mesh_terms: D000818:Animals; D001042:Aphids / Q000276:immunology / Q000382:microbiology* / Q000469:parasitology; D005075:Biological Evolution; D060467:Disease Resistance; D004198:Disease Susceptibility / Q000276:immunology / Q000382:microbiology / Q000469:parasitology; D005260:Female; D020563:Gammaproteobacteria / Q000254:growth & development*; D005838:Genotype; D006790:Host-Parasite Interactions; D016014:Linear Models; D010058:Oviposition; D010312:Parthenogenesis; D013559:Symbiosis; D014863:Wasps / Q000472:pathogenicity