Wolbachia (red) in insect testes (blue)VANDERBILT UNIVERSITY, SETH BORDENSTEINTwo papers published in Nature and Nature Microbiology yesterday (February 27) resolve one of the longest-standing puzzles in entomology: how Wolbachia bacteria cause cytoplasmic incompatibility (CI) in their insect hosts. This strategic sterility, in which bacteria-infected female insects can reproduce readily while uninfected ones struggle, turns out to be regulated by two neighboring bacterial genes that encode interacting proteins. The identification of the genes could aid research into, among other things, Wolbachia-based insect–control strategies.
“It’s really exciting,” said microbiologist Steven Sinkins of the University of Glasgow, U.K., who was not involved in the work. “For Wolbachia researchers this has been the big unanswered question—how the bacteria induce this reproductive manipulation—and this is a convincing breakthrough in terms of identifying the genes that are responsible.”
Wolbachia bacteria are intracellular parasites that infect approximately two-thirds of the world’s arthropods. Passed onto offspring via infection of the egg, but not sperm, these bacteria have developed a range of reproduction-manipulating mechanisms that ensure their continued prevalence. Chief among these is CI, a phenomenon in which infected males can only successfully reproduce with infected females. Matings with uninfected females result in early embryonic death. In some cases, matings with females carrying a competing Wolbachia ...
