Wolbachia cifB induces cytoplasmic incompatibility in the malaria mosquito vector

Abstract

Wolbachia, a maternally inherited intracellular bacterial species, can manipulate host insect reproduction by cytoplasmic incompatibility (CI), which results in embryo lethality in crosses between infected males and uninfected females. CI is encoded by two prophage genes, cifA and cifB. Wolbachia, coupled with the sterile insect technique, has been used in field trials to control populations of the dengue vector Aedes albopictus, but CI-inducing strains are not known to infect the malaria vector Anopheles gambiae. Here we show that cifA and cifB can induce conditional sterility in the malaria vector An. gambiae. We used transgenic expression of these Wolbachia-derived genes in the An. gambiae germline to show that cifB is sufficient to cause embryonic lethality and that cifB-induced sterility is rescued by cifA expression in females. When we co-expressed cifA and cifB in male mosquitoes, the CI phenotype was attenuated. In female mosquitoes, cifB impaired fertility, which was overcome by co-expression of cifA. Our findings pave the way towards using CI to control malaria mosquito vectors.

The CinB Nuclease from w No Wolbachia Is Sufficient for Induction of Cytoplasmic Incompatibility in Drosophila

“…2B ). Very recently, transgenic expression of w Pip CidA and CidB proteins in the malaria vector Anopheles gambiae has been reported ( 29 ). Expression of CidB w Pip by itself in male mosquitoes induced very strong transgenic CI, and CidA w Pip in females was sufficient to block the embryonic lethality caused by crossing to transgenic cidB w Pip male mosquitoes.…”

Symbionts and gene drive: two strategies to combat vector-borne disease

“…CI phenotypes can also be replicated with crosses between transgenic insects expressing cif genes and insects harboring native Wolbachia infection [45]. While most of these studies examining the molecular basis of CI have been accomplished in flies [45][46][47][48], CI was also recapitulated by expression of cif genes from wPip in Anopheles mosquitoes (though here, only cifB was needed in males to induce CI) [49], demonstrating these approaches can be transferred to medically important vector species. Further insights into the molecular mechanism(s) underpinning CI will enable evaluation of how these systems will function in the field and how resistance might emerge.…”

Harnessing Wolbachia cytoplasmic incompatibility alleles for confined gene drive: a modeling study

“…In our Drosophila model, no offspring are created if the male has both CifA and CifB, and the female has no CifA allele [50][51][52]. In the Anopheles gambiae model, only CifB is required in males to impose the toxin effect, so that when a male with CifB mates with a female without CifA, they will also have no offspring [54].…”