Bidirectional Cytoplasmic Incompatibility Induced by Cross-Order Transfection of Wolbachia: Implications for Control of the Host Population

Yong Zhong, Zheng-Xi Li

Wolbachia are widespread endosymbionts in arthropods and some nematodes. This genus of bacteria is known to manipulate host reproduction by inducing cytoplasmic incompatibility (CI). This important phenotype is implicated in the control of host populations since Wolbachia can suppress host populations through the induction of CI in a way similar to the sterile insect technique. Here, we identified a candidate CI-inducing Wolbachia strain from the parasitic wasp Scleroderma guani (wSguBJ) by sequencing and phylogenetic analysis. This Wolbachia strain was then isolated, purified, and artificially transfected into the new whitefly host Bemisia tabaci through nymphal microinjection. Infection frequency monitoring by molecular detection showed that 60-80 % of the offspring from transfected whitefly populations was infected with wSguBJ six generations after the transfer. Laboratory rearing experiments indicated that the artificial transfection caused no significant difference in the numbers of offspring between the transfected and naturally infected populations and had no significant detrimental effects on the development of transfected males, although the development of transfected females was delayed. Reciprocal crossings revealed that bidirectional CI was induced between the transfected and naturally infected whiteflies. These data indicated that the cross-order transfer of the heterologous Wolbachia strain by nymphal microinjection was successful. Mass release of the transfected males that could stably carry the heterologous Wolbachia without significant compromise of fecundity/development may provide an alternative approach to control of host populations.