PRESENTATION STUDIO AT SFU'S BIG DATA HUB, ASB 10900
Dr. Christoph Vorburger, Swiss Federal Institute of Aquatic Science and Technology
Symbionts mediate host-parasitoid coevolution in insects
Many insects harbor endosymbionts that are passed on faithfully from mother to offspring. Vertical transmission couples host and symbiont fitness to a large extent and has thus facilitated the evolution of defense mechanisms by which symbionts protect their hosts against parasites. Drawing mostly on the example of the black bean aphid, Aphis fabae, and its defensive symbiont Hamiltonella defensa, I show that endosymbionts can play an important role in mediating host-parasitoid coevolution. Endosymbionts increase the heritable variation available to selection, they alter the specificity of the host-parasitoid interaction as a consequence of genotype-by-genotype interactions, and they modify the trade-off between resistance to parasitoids and other components of fitness. Models show that these complex three-way interactions can lead to coevolutionary dynamics that are not observed in the absence of symbionts. Our lab is currently shifting its attention towards the parasitoids' side of the interaction, and I will present some our first attempts to understand the evolution of parasitoid counteradaptations to symbiont-conferred resistance.