Transgenic expression ofcifgenes fromWolbachiastrainwAlbB recapitulates cytoplasmic incompatibility inAedes aegypti

Abstract

AbstractThe endosymbiotic bacteriaWolbachiacan invade insect populations by modifying host reproduction through cytoplasmic incompatibility (CI), an effect that results in embryonic lethality whenWolbachia-carrying males mate withWolbachia-free females. Here we describe a transgenic system for recreating CI in the major arbovirus vectorAedes aegyptiusing CI factor (cif) genes fromwAlbB, aWolbachiastrain currently being deployed to reduce dengue transmission. CI-like sterility was induced whencifAandcifBwere co-expressed in testes; this sterility could be rescued by maternalcifAexpression, thereby reproducing the pattern ofWolbachia-induced CI. Expression ofcifBalone was associated with extensive DNA damage and disrupted spermatogenesis. The strength of rescue by maternalcifAexpression was dependent on the comparative levels ofcifA/cifBexpression in males. These findings are consistent with CifB acting as a toxin and CifA as an antitoxin, with CifA attenuating CifB toxicity in both the male germline and in developing embryos.