摘要：SummaryCytoplasmic incompatibility (CI) is a form of reproductive manipulation caused by maternally inherited endosymbionts infecting arthropods, likeWolbachia, whereby matings between infected males and uninfected females produce few or no offspring. We report the discovery of a new CI symbiont, a strain ofSpiroplasma causing CI in the parasitoid waspLariophagus distinguendus. Its extracellular occurrence enabled us to establish CI in uninfected adult insects by transferringSpiroplasma-infected hemolymph. We sequenced the CI-Spiroplasmagenome and did not find any homologues of any of thecifgenes discovered to cause CI inWolbachia, suggesting independent evolution of CI. Instead, the genome contains other potential CI-causing candidate genes, such as homologues of high-mobility group (HMG) box proteins that are crucial in eukaryotic development but rare in bacterial genomes.Spiroplasma’s extracellular nature and broad host range encompassing medically and agriculturally important arthropods make it a promising tool to study CI and its applications.Graphical abstractDisplay OmittedHighlights•ASpiroplasmastrain induces cytoplasmic incompatibility (CI) in a parasitoid wasp•Spiroplasmaand CI are efficiently transferred to naive hosts by hemolymph injection•The CI-Spiroplasmagenome contains potential CI-causing genes, but noWolbachia cifs•Absence ofcifgenes in theSpiroplasmagenome suggests an independent origin of CIZoology; Entomology; Microbiology; Microbiology parasite
