TY - JOUR A1 - Dennis, Alice B. A1 - Patel, Vilas A1 - Oliver, Kerry M. A1 - Vorburger, Christoph T1 - Parasitoid gene expression changes after adaptation to symbiont-protected hosts JF - Evolution N2 - Reciprocal selection between aphids, their protective endosymbionts, and the parasitoid wasps that prey upon them offers an opportunity to study the basis of their coevolution. We investigated adaptation to symbiont‐conferred defense by rearing the parasitoid wasp Lysiphlebus fabarum on aphids (Aphis fabae) possessing different defensive symbiont strains (Hamiltonella defensa). After ten generations of experimental evolution, wasps showed increased abilities to parasitize aphids possessing the H. defensa strain they evolved with, but not aphids possessing the other strain. We show that the two symbiont strains encode different toxins, potentially creating different targets for counter‐adaptation. Phenotypic and behavioral comparisons suggest that neither life‐history traits nor oviposition behavior differed among evolved parasitoid lineages. In contrast, comparative transcriptomics of adult female wasps identified a suite of differentially expressed genes among lineages, even when reared in a common, symbiont‐free, aphid host. In concurrence with the specificity of each parasitoid lineages’ infectivity, most differentially expressed parasitoid transcripts were also lineage‐specific. These transcripts are enriched with putative venom toxins and contain highly expressed, potentially defensive viral particles. Together, these results suggest that wild populations of L. fabarum employ a complicated offensive arsenal with sufficient genetic variation for wasps to adapt rapidly and specifically to their hosts’ microbial defenses. KW - Adaptation KW - experimental evolution KW - gene expression KW - Lysiphlebus fabarum KW - parasitoid KW - venom Y1 - 2017 U6 - https://doi.org/10.1111/evo.13333 SN - 0014-3820 SN - 1558-5646 VL - 71 SP - 2599 EP - 2617 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Coloma, Sebastian A1 - Gaedke, Ursula A1 - Sivonen, Kaarina A1 - Hiltunen, Teppo T1 - Frequency of virus-resistant hosts determines experimental community dynamics JF - Ecology : a publication of the Ecological Society of America N2 - Parasites, such as bacterial viruses (phages), can have large effects on host populations both at the ecological and evolutionary levels. In the case of cyanobacteria, phages can reduce primary production and infected hosts release intracellular nutrients influencing planktonic food web structure, community dynamics, and biogeochemical cycles. Cyanophages may be of great importance in aquatic food webs during large cyanobacterial blooms unless the host population becomes resistant to phage infection. The consequences on plankton community dynamics of the evolution of phage resistance in bloom forming cyanobacterial populations are still poorly studied. Here, we examined the effect of different frequencies of a phage-resistant genotype within a filamentous nitrogen-fixing Nodularia spumigena population on an experimental plankton community. Three Nodularia populations with different initial frequencies (0%, 5%, and 50%) of phage-resistant genotypes were inoculated in separate treatments with the phage 2AV2, the green alga Chlorella vulgaris, and the rotifer Brachionus plicatilis, which formed the experimental plankton community subjected to either nitrogen-limited or nitrogen-rich conditions. We found that the frequency of the phage-resistant Nodularia genotype determined experimental community dynamics. Cyanobacterial populations with a high frequency (50%) of the phage-resistant genotype dominated the cultures despite the presence of phages, retaining most of the intracellular nitrogen in the plankton community. In contrast, populations with low frequencies (0% and 5%) of the phage-resistant genotype were lysed and reduced to extinction by the phage, transferring the intracellular nitrogen held by Nodularia to Chlorella and rotifers, and allowing Chlorella to dominate the communities and rotifers to survive. This study shows that even though phages represent minuscule biomass, they can have key effects on community composition and eco-evolutionary feedbacks in plankton communities. KW - cyanobacteria KW - eco-evolutionary feedbacks KW - experimental evolution KW - host-parasite interaction KW - phage resistance KW - predator-prey interaction Y1 - 2018 U6 - https://doi.org/10.1002/ecy.2554 SN - 0012-9658 SN - 1939-9170 VL - 100 IS - 1 PB - Wiley CY - Hoboken ER -