Data from: Unearthing carrion beetles’ microbiome: characterization of bacterial and fungal hind-gut communities across the Silphidae

Carrion beetles (Coleoptera, Silphidae) are well-known for their behavior of exploiting vertebrate carcasses for nutrition. While species in the subfamily Silphinae feed on large carcasses and on larvae of competing scavengers, the Nicrophorinae are unique in monopolizing, burying, and defending small carrion, and providing extensive biparental care. As a first step towards investigating whether microbial symbionts may aid in carcass utilization or defense, we characterized the microbial hind-gut communities of six Nicrophorinae (Nicrophorus spp.) and two Silphinae species (Oiceoptoma noveboracense and Necrophila americana) by deep ribosomal RNA amplicon sequencing. Across all species, bacteria in the family Xanthomonadaceae, related to Ignatzschineria larvae, were consistently common, and several other taxa were present in lower abundance (Enterobacteriales, Burkholderiales, Bacilli, Clostridiales, and Bacteroidales). Additionally, the Nicrophorinae showed high numbers of unusual Clostridiales, while the Silphinae were characterized by Flavobacteriales and Rhizobiales (Bartonella sp.). In addition to the complex community of bacterial symbionts, each species of carrion beetle harbored a diversity of ascomycetous yeasts closely related to Yarrowia lipolytica. Despite the high degree of consistency in microbial communities across the Silphidae – specifically within the Nicrophorinae – both the fungal symbiont phylogeny and distance-based bacterial community clustering showed more congruence with sampling locality than host phylogeny. Thus, despite the possibility for vertical transmission, the distinct hind-gut microbiota of the Silphidae appears to be shaped by frequent horizontal exchange or environmental uptake of symbionts. The microbial community profiles, together with information on host ecology and the metabolic potential of related microorganisms, allow us to propose hypotheses on putative roles of the symbionts in carcass degradation, detoxification, and defense.