Screening of reproductive endosymbionts indicates Wolbachia flourish alone across fig wasps (Hymenoptera: Chalcidoidea).

摘要

Reproductive endosymbionts including Wolbachia are important heritable bacteria. They can manipulate the reproduction of their hosts, as well as affect the fitness and evolution of hosts. Many insects are co-infected by more than one reproductive endosymbionts. Detection of such multiple infections plays a significant role to comprehensively understand the association between endosymbionts and their hosts. Fig wasps live in the enclosed syconia and exhibit high incidence of Wolbachia. However, we have no knowledge about whether fig wasps are infected by other reproductive endosymbionts. We screened seven common reproductive endosymbionts, Cardinium, Arsenophonus, Rickettsia, Spiroplasma ixodetis, Spiroplasma poulsonii, Flavobacterium and Wolbachia in fig wasps using standard PCR. Except Wolbachia, we found no other reproductive bacteria in 1215 individuals of 66 fig wasp species. The prevalence of Wolbachia is up to 79%. The results indicate that the enclosed syconia may cut off the horizontal transmission of some reproductive bacteria from outside as a physical barrier. Meanwhile, it implies that Wolbachia may be the only heritable endosymbiont in fig wasps, which makes them an ideal model to dip into the tight relationship between Wolbachia and fig wasps.