Tissue- and population-level microbiome analysis of the wasp spiderArgiope bruennichiidentifies a novel dominant bacterial symbiont

BackgroundRecognition is growing that many ecological and evolutionary processes in animals are dependent upon microbial symbioses. Although there is much known about the ecology and evolution of spiders, the role of the microbiome in these processes remains mostly unknown. We conducted an exploratory study of the microbiome of a range-expanding spider, comparing between populations, individuals, and tissue types (leg, prosoma, hemolymph, book lungs, ovaries, silk glands, midgut, and fecal pellets). Our study is one of the very first to go beyond targeting known endosymbionts in spiders, and characterizes the total microbiome across different body compartments.nnResultsThe microbiome of the wasp spider Argiope bruennichi is dominated by a novel bacterial symbiont, which is highly abundant in every tissue type in spiders from geographically distinct populations, and also present in offspring. The novel symbiont is affiliated with the Tenericutes, but has low sequence identity (