The objective of this paper is to clarify the effect of Wolbachia on gene expression in a particular symbiotic association in which Wolbachia affects developmental processes, through its effect on wasp oogenesis. For that purpose, we used both global and dedicated transcriptomic approaches. Even though A. tabida is a model system in host/parasitoid and host/Wolbachia interactions, no genetic data were available for this parasitoid wasp. Thus, the first aim of this study was to build a reference transcriptome based on several tissues selleck compound (ovaries, whole females) and physiological conditions

(symbiosis, immune challenge). By sequencing 10 cDNA libraries (one of which is a normalized library), we provide here the first large-scale, genetic information on this wasp. The second aim of the study was to better understand how dependence arose in this particular species by deciphering the molecular mechanisms underlying this evolutionary transition.

An overview of functions that could be differentially expressed in response to symbiosis was outlined through in silico analyses on ovaries EST libraries (Gene Ontology-based bioinformatics) and in vitro subtractions (Suppressive Subtraction Hybridizations). Then, we focused on candidate JIB04 manufacturer genes involved in immunity (broad sense), programmed cell death and oogenesis; functions which could play a major role in the control of ovarian phenotype through pleiotropy. Using quantitative real-time PCR, we thus characterized the effect of symbiosis on host gene expression in both PIK3C2G males and females, in two populations exhibiting extreme ovarian phenotypes. Methods Biological system Ecology Asobara tabida (Hymenoptera: Braconidae) is a solitary endoparasitoid laying its eggs into the first or second instar larvae of Drosophila species. After Drosophila pupation, the parasitoid becomes an ectoparasite, and consumes its host before it itself pupates prior to emerging. A. tabida is naturally infected by three strains of the intracellular bacterium

Wolbachia (wAtab1, wAtab2 and wAtab3): wAtab1 and wAtab2 induce cytoplasmic incompatibility, and only wAtab3 is required for oogenesis completion [6, 25]. Polymorphism of ovarian phenotype in populations After Wolbachia removal, the ovarian phenotype displays a high level of intra-species variation: whereas uninfected DMXAA clinical trial females of the Pi strain (Pierrefeu, France) produce no eggs, uninfected females of the NA strain (Saanich, Canada) produce a small number of aborting eggs [7]. In this study, we used the NA strain and a Pi-derived strain (Pi3). Pi3 was obtained by moderate antibiotic treatment, and contains only the obligatory Wolbachia strain wAtab3 [25]. The lines are stable, and have been maintained by regular sib-matings without antibiotic treatment for about 100 generations.