Culex pipiens crossing type diversity is governed by an amplified and polymorphic operon of Wolbachia

Manon Bonneau (1) , Célestine Atyame Nten (1, 2) , Marwa Beji (3) , Fabienne Justy (1) , Martin Cohen-Gonsaud (4) , Mathieu Sicard (1) , Mylène Weill (1)

1 UMR ISEM - Institut des Sciences de l'Evolution de Montpellier
2 PIMIT - Processus Infectieux en Milieu Insulaire Tropical
3 Institut Pasteur de Tunis
4 CBS - Centre de Biochimie Structurale [Montpellier]

Culex pipiens mosquitoes are infected with Wolbachia (wPip) that cause an important diversity of cytoplasmic incompatibilities (CIs). Functional transgenic studies have implicated the cidA-cidB operon from wPip and its homolog in wMel in CI between infected Drosophila males and uninfected females. However, the genetic basis of the CI diversity induced by different Wolbachia strains was unknown. We show here that the remarkable diversity of CI in the C. pipiens complex is due to the presence, in all tested wPip genomes, of several copies of the cidA-cidB operon, which undergoes diversification through recombination events. In 183 isofemale lines of C. pipiens collected worldwide, specific variations of the cidA-cidB gene repertoires are found to match crossing types. The diversification of cidA-cidB is consistent with the hypothesis of a toxin–antitoxin system in which the gene cidB co-diversifies with the gene cidA, particularly in putative domains of reciprocal interactions.

Domains: Life Sciences [q-bio]; Life Sciences [q-bio]; Microbiology and Parasitology

Manon Bonneau, Célestine Atyame Nten, Marwa Beji, Fabienne Justy, Martin Cohen-Gonsaud, et al.. Culex pipiens crossing type diversity is governed by an amplified and polymorphic operon of Wolbachia. Nature Communications, 2018, 9 (1), pp.319. ⟨10.1038/s41467-017-02749-w⟩. ⟨pasteur-01728878⟩