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Heredity (2009) 103, 248256
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ORIGINAL ARTICLE
A new case of Wolbachia dependence in the genus Asobara: evidence for parthenogenesis induction in Asobara japonica
N Kremer1, D Charif1, H Henri1, M Bataille1, G Prvost2, K Kraaijeveld3 and F Vavre1
1Universit de Lyon, F-69000, Lyon; Universit Lyon 1; CNRS, UMR5558, Laboratoire de Biomtrie et Biologie Evolutive, F-69622, Villeurbanne, France; 2Laboratoire de Biologie des Entomophages (EA 3900), Universit de Picardie Jules Verne, F-80039, Amiens, France and 3Department of Animal Ecology, Institute of Biology Leiden, Leiden University, Leiden, The Netherlands
Wolbachia is a maternally inherited bacterium that is widely distributed among arthropods, in which it manipulates the reproduction of its hosts. Although generally facultative for its hosts, Wolbachia has recently become obligatory in Asobara tabida (Hymenoptera: Braconidae) in which it is required for the completion of oogenesis. Here, we describe a new Wolbachia strain (wAjap) that is associated with the genus Asobara and infects Asobara japonica. wAjap was detected in all female-biased populations of A. japonica found in the main islands of Japan, but not in the arrhenotokous populations from the southern islands. Using phylogenetic analyses based on multi-locus sequence typing (MLST), we show that this strain is closely related to wAtab3 (the strain required for oogenesis in A. tabida), even though they differ on Wolbachia surface protein (WSP) and WO phage sequences. Using antibiotic treatments, we show that cured thelytokous females are not dependent on Wolbachia for
oogenesis. However, they produced only sons, showing that wAjap induces thelytokous parthenogenesis. Analyses of mating behavior and offspring production of individuals from Wolbachia-infected populations showed that while males were still sexually functional, females no longer attract males, making Wolbachia an obligate partner for daughter production in thelytokous populations. The fact that Wolbachia has become independently obligatory in two species of the same genus tends to show that dependence evolution can be common and swift, although no clear benet for the parasitoid can be attributed to this dependence. Although dependence should lead to co-divergence between Wolbachia and its hosts, the very few cases of co-speciation observed in hostWolbachia associations question the stability of these obligatory associations.
Heredity (2009) 103, 248256; doi:http://dx.doi.org/10.1038/hdy.2009.63
Web End =10.1038/hdy.2009.63 ; published online 10...