Stable coexistence of incompatible Wolbachia along a narrow contact zone in mosquito field populations. Issue 2 (9th January 2015)

• Record Type: Journal Article
• Authors: Atyame, Célestine M.; Labbé, Pierrick; Rousset, François; Beji, Marwa; Makoundou, Patrick; Duron, Olivier; Dumas, Emilie; Pasteur, Nicole; Bouattour, Ali; Fort, Philippe; Weill, Mylène
• Is Part Of: Molecular ecology. Volume 24:Issue 2(2015)
• Page Start: 508
• Page End: 521
• Publication Date: 2015-01-09
• Subjects: Molecular ecology -- Periodicals; Molecular population biology -- Periodicals; 576
• DOI: 10.1111/mec.13035
• Languages: English
• ISSNs: 0962-1083

Abstract

<abstract abstract-type="main" id="mec13035-abs-0001"> <title>Abstract</title> <p>In arthropods, the intracellular bacteria <italic>Wolbachia</italic> often induce cytoplasmic incompatibility (CI) between sperm and egg, which causes conditional embryonic death and promotes the spatial spread of <italic>Wolbachia</italic> infections into host populations. The ability of <italic>Wolbachia</italic> to spread in natural populations through CI has attracted attention for using these bacteria in vector‐borne disease control. The dynamics of incompatible <italic>Wolbachia</italic> infections have been deeply investigated theoretically, whereas in natural populations, there are only few examples described, especially among incompatible infected hosts. Here, we have surveyed the distribution of two molecular <italic>Wolbachia</italic> strains (<italic>w</italic>Pip11 and <italic>w</italic>Pip31) infecting the mosquito <italic>Culex pipiens</italic> in Tunisia. We delineated a clear spatial structure of both infections, with a sharp contact zone separating their distribution areas. Crossing experiments with isofemale lines from different localities showed three crossing types: <italic>w</italic>Pip11‐infected males always sterilize <italic>w</italic>Pip31‐infected females; however, while most <italic>w</italic>Pip31‐infected males were compatible with <italic>w</italic>Pip11‐infected females, a few completely sterilize them. The <italic>w</italic>Pip11 strain was thus expected to spread, but temporal dynamics over 7 years of monitoring shows the stability of the contact zone. We examined which factors may contribute to the observed stability, both theoretically and empirically. Population cage experiments, field samples and modelling did not support significant impacts of local adaptation or assortative mating on the stability of <italic>w</italic>Pip infection structure. By contrast, low dispersal probability and metapopulation dynamics in the host <italic>Cx. pipiens</italic> probably play major roles. This study highlights the need of understanding CI dynamics in natural populations to design effective and sustainable <italic>Wolbachia</italic>‐based control strategies.</p> </abstract>