Vorburger
Fakultäten » Mathematisch-naturwissenschaftliche Fakultät » Evolutionsbiologie und Umweltwissenschaften, Institut für » Ecology & Environment » Prof. Dr. Heinz-Ulrich Reyer (emeritiert) » Vorburger
Completed research project
| Title / Titel | Clonal diversity, genotypic interactions and coevolution in asexual antagonists | ||
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| Abstract (PDF, 14 KB) | |||
| Summary / Zusammenfassung | A leading hypothesis for the maintenance of sexual reproduction proposes that sex provides an escape from coevolving parasites (the Red Queen hypothesis). For coevolution to occur, there must be genetic variation for resistance in hosts and for virulence in parasites. Also, host-parasite interactions must be genotype-specific and/or increased resistance and virulence must incur costs. This seems to be fulfilled in many host-parasite systems, yet observations of the predicted genetic dynamics are virtually lacking, possibly because the genetic basis of resistance and virulence is often unknown and because of the long time-scale over which coevolution occurs. These problems may be overcome by taking advantage of an unusual but natural situation: asexual hosts that are attacked by asexual parasites, both with very short generation times. The parasitoid wasp Lysiphlebus fabarum is asexual over parts of its range in Europe and an important natural enemy of its (cyclically) parthenogenetic host Aphis fabae, the black bean aphid. Using clonal genotypes of host and parasitoid circumvents the need to identify the genes underlying resistance or infectivity because they are linked to the rest of the genome, allowing the use of standard molecular markers to distinguish resistance/infectivity genotypes and track their temporal dynamics. In a first step, we will determine the natural distribution of genotypic diversity in hosts and parasitoids and establish a collection of asexual aphid and wasp lineages. In a second step, we will measure genetic variation for resistance and virulence. If genotype-specificity is detected, we will set up experimental host-parasitoid populations to test for the occurrence of the expected genetic dynamics. If no genotype-specificity is found, we will search for costs of resistance and virulence that must then be postulated to explain the observed genetic diversity for these traits in natural populations. | ||
| Publications / Publikationen | Sandrock, C., N. Frauenfelder, S. von Burg, and C. Vorburger. 2007. Microsatellite DNA markers for the aphid parasitoid Lysiphlebus fabarum and their applicability to related species. Molecular Ecology Notes 7: 1080-1083.von Burg, S., J. Ferrari, C. B. Müller, and C. Vorburger. 2008. Genetic variation and covariation of susceptibility to parasitoids in the aphid Myzus persicae – no evidence for trade-offs. Proceedings of the Royal Society London B 275: 1089-1074.Vorburger, C., S. E. Gegenschatz, G. Ranieri, and P. Rodriguez. 2008. Limited scope for maternal effects in aphid defence against parasitoids. Ecological Entomology 33: 189-196.Vorburger, C., A. Gouskov, and S. von Burg. 2008. Genetic covariation between effectiveness and cost of defence in aphids. Biology Letters 4: 674-676. | ||
| Keywords / Suchbegriffe | antagonistic coevolution, aphids, asexual reproduction, frequency-dependent selection, genetic diversity, parasitoids, Red Queen hypothesis, resistance | ||
| Project leadership and contacts / Projektleitung und Kontakte |
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| Other links to external web pages | http://www.zool.uzh.ch/static/ecology/people/cvorburger/ | ||
| Funding source(s) / Unterstützt durch |
SNF (Personen- und Projektförderung) |
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| Duration of Project / Projektdauer | Dec 2005 to Jan 2009 |