Recombination data for Wolbachia and Spiroplasma infected flies

Wolbachia pipientis is an intracellular alphaproteobacterium that infects
40-60% of insect species and is well known for host reproductive
manipulations. Although Wolbachia are primarily maternally transmitted,
evidence of horizontal transmission can be found in incongruent
host-symbiont phylogenies and recent acquisitions of the same Wolbachia
strain by distantly related species. Parasitoids and predator-prey
interactions may indeed facilitate the transfer of Wolbachia between
insect lineages but it is likely that Wolbachia are acquired via
introgression in many cases. Many hypotheses exist as to explain Wolbachia
prevalence and penetrance such as nutritional supplementation, protection
from parasites, protection from viruses, or straight up reproductive
parasitism. Using classical genetics we show that Wolbachia increase
recombination in infected lineages across two genomic intervals. This
increase in recombination is titer dependent as the wMelPop variant, which
infects at higher load in Drosophila melanogaster, increases recombination
5% more than the wMel variant. In addition, we also show that Spiroplasma
poulsonii, the other bacterial intracellular symbiont of Drosophila
melanogaster, does not induce an increase in recombination. Our results
suggest that Wolbachia infection specifically alters host recombination
landscape in a dose dependent manner.