RRapid global spread of wRi-like Wolbachia across multiple Drosophila

Maternally transmitted Wolbachia, Spiroplasma and Cardinium bacteria are common in insects, but their interspecific spread is poorly understood. Endosymbionts can spread rapidly within host species by manipulating host reproduction, as typified by the global spread of wRi Wolbachia observed in Drosophila simulans. However, because Wolbachia cannot survive outside host cells, spread between distantly related host species requires horizontal transfers that are presumably rare. Here we document spread of wRi-like Wolbachia among eight highly diverged Drosophila hosts (10–50 million years) over only about 14,000 years (5,000–27,000). Comparing 110 wRi-like genomes, we find ≤0.02% divergence from the wRi variant that spread rapidly through California populations of D. simulans. The hosts include both globally invasive species, D. simulans, D. suzukii and D. ananassae , and narrowly distributed Australian endemics, D. anomalata and D. pandora. Phylogenetic analyses that include mtDNA genomes ...