Wolbachia diversity and cytoplasmic incompatibility patterns in Culex pipiens populations in Turkey

Abstract

BackgroundWolbachia are maternally transmitted bacteria that can manipulate their hosts’ reproduction causing cytoplasmic incompatibility (CI). CI is a sperm-egg incompatibility resulting in embryonic death. Due to this sterilising effect on mosquitoes, Wolbachia are considered for vector control strategies. Important vectors for arboviruses, filarial nematodes and avian malaria, mosquitoes of Culex pipiens complex are suitable for Wolbachia-based vector control. They are infected with Wolbachia wPip strains belonging to five genetically distinct groups (wPip-I to V) within the Wolbachia B supergroup. CI properties of wPip strongly correlate with this genetic diversity: mosquitoes infected with wPip strains from a different wPip group are more likely to be incompatible with each other. Turkey is a critical spot for vector-borne diseases due to its unique geographical position as a natural bridge between Asia, Europe and Africa. However, general wPip diversity, distribution and CI patterns in natural Cx. pipiens (s.l.) populations in the region are unknown. In this study, we first identified wPip diversity in Turkish Cx. pipiens (s.l.) populations, by assigning them to one of the five groups within wPip (wPip-Ito V). We further investigated CI properties between different wPip strains from this region.ResultsWe showed a wPip fixation in Cx. pipiens (s.l.) populations in Turkey by analysing 753 samples from 59 sampling sites. Three wPip groups were detected in the region: wPip-I, wPip-II and wPip-IV. The most dominant group was wPip-II. While wPip-IV was restricted to only two locations, wPip-I and wPip-II had wider distributions. Individuals infected with wPip-II were found co-existing with individuals infected with wPip-I or wPip-IV in some sampling sites. Two mosquito isofemale lines harbouring either a wPip-I or a wPip-II strain were established from a population in northwestern Turkey. Reciprocal crosses between these lines showed that they were fully compatible with each other but bidirectionally incompatible with wPip-IV Istanbul infected line.ConclusionOur findings reveal a high diversity of wPip and CI properties in Cx. pipiens (s.l.) populations in Turkey. Knowledge on naturally occurring CI patterns caused by wPip diversity in Turkey might be useful for Cx. pipiens (s.l.) control in the region.

Variation in Wolbachia cidB gene, but not cidA, is associated with cytoplasmic incompatibility mod phenotype diversity in Culex pipiens

“…A total of 67 isofemale lines were established from larvae collected at four sites in the province of Trento in the North‐East of Italy (San Michele all'Adige, Roveré Della Luna, Mezzocorona and Zambana: Data ), because it was already known that w Pip strains from the w PipIV group occurred in this area (Dumas et al, ). The PCR‐RFLP test as described in Altinli et al () confirmed that all isofemale lines were infected with w PipIV strains. Crosses between males from these 67 isofemale lines and females from the w PipI Tunis laboratory line (reference line used for the screening) led to sort the lines according to the two mod phenotypes previously described (Atyame et al, ; Bonneau, Atyame, et al, ): the males from 62 isofemale lines from North Italy were found incompatible with Tunis females (qualified as incompatible isofemale lines) and five lines exhibited males compatible with Tunis females (qualified as compatible isofemale lines: Data ).…”

“…The PCR-RFLP test as described in Altinli et al (2018) confirmed that all isofemale lines were infected with wPipIV strains. Crosses between males from these 67 isofemale lines and females from the wPipI Tunis laboratory line (reference line used for the screening) led to sort the lines according to the two mod phenotypes previously described (Atyame et al, 2015;Bonneau, Atyame, et al, 2018): the males from 62 isofemale lines from North Italy were found incompatible with Tunis females (qualified as incompatible isofemale lines) and five lines exhibited males compatible with Tunis females (qualified as compatible isofemale lines: Data S1).…”

Sharing cells with Wolbachia: the transovarian vertical transmission of Culex pipiens densovirus

“…To test the effect of the Wolbachia genetic differences on CpDV amount and their vertical transmission we used three isofemale lines Tunis, Harash and Slab (Supporting Information Table 1) that are infected with wPip I, wPip IV and wPip III respectively. wPip groups of these lines have been assigned based on a PCR/RFLP test on pool of larvae using pk1 primers as previously described (Dumas et al, 2013;Altinli et al, 2018) and were regularly verified during the experiments. We introduced the cytoplasm of Tunis and Harash lines, along with their respective wPip strains, into the Slab nuclear background as described by Duron and colleagues (2012).…”

Mosquito-Borne Viruses and Insect-Specific Viruses Revealed in Field-Collected Mosquitoes by a Monitoring Tool Adapted from a Microbial Detection Array

“…mosquitoes but was not found in A. aegypti. Further characterization of the presence and strain types of locally occurring insect-specific viruses and Wolbachia is important (77,78) for possible biologically based control interventions (66,79,80). This study presents the broad detection capability, sensitivity, and ease of use of the LLMDA approach for surveillance of mosquito-borne diseases of medical importance.…”