Permanent URL to this publication: http://dx.doi.org/10.5167/uzh-18879
Vorburger, C; Sandrock, C; Gouskov, A; Castaneda, L E (2009). Genotypic variation and the role of defensive endosymbionts in all-parthenogenetic host-parasitoid interaction. Evolution, 63(6):1439-1450.
Models of host-parasite coevolution predict pronounced genetic dynamics if resistance and infectivity are genotype-specific or associated with costs, and if selection is fueled by sufficient genetic variation. We addressed these assumptions in the black bean aphid, Aphis fabae, and its parasitoid Lysiphlebus fabarum, Parasitoid genotypes differed in infectivity and host clones exhibited huge variation for susceptibility. This variation occurred at two levels. Clones harboring Hamiltonella defensa, a bacterial endosymbiont known to protect pea aphids against parasitoid enjoyed greatly reduced susceptibility, yet clones without H. defensa also exhibited significant variation. Although there was no evidence for genotype-specificity in the H. defensa-free clones interaction with parasitoids, we found such evidence in clones containing the bacterium. This suggests that parasitoid genotypes differ in their ability to overcome H. defensa, resulting in an apparent host x parasit
oid genotype interaction that may be in fact be due to an underlying symbiont x parasitoid genotype interaction. Aphid susceptibility to parasitoids correlated negatively with fecundity and rate of increase, due to H. defensa-bearing clones being more fecund on average. Hence, possessing symbionts may also be favorable in the absence of parasitoids, which raises the question why H. defensa does not go to fixation and highlights the need to develop new models to understand the dynamics of endosymbiont-mediated coevolution.
|Item Type:||Journal Article, refereed, original work|
|Communities & Collections:||07 Faculty of Science > Institute of Evolutionary Biology and Environmental Studies|
|DDC:||570 Life sciences; biology|
590 Animals (Zoology)
|Uncontrolled Keywords:||Aphids, Aphis fabae fabae, costs of resistance, genetic correlations, Hamiltonella defensa, Lysiphlebus fabarum, Regiella insectiocola, symbiosis, trade-offs|
|Date:||18 February 2009|
|Deposited On:||12 Jun 2009 08:45|
|Last Modified:||23 Nov 2012 16:15|
|Additional Information:||Author Posting. © The Authors 2009. This is the author's version of the work. It is posted here for personal use, not for redistribution. The definitive version was published in Evolution, International Journal of Organic Evolution, Volume 63, Issue 6, Pages 1439-1450. 10.1111/j.1558-5646.2009.00660.x.|
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