SRA

The ecological interactions between microbes and multicellular organisms have shaped the evolution of both, especially in the case of eukaryotes. Whether through the formation of a symbiotic relationship or by acting as a food source, microbes, and particularly bacteria, can modulate the host's metabolism as well as their immune system. Therefore, the investigation of interspecies interactions is necessary to understand the response mechanism of an organism within an ecological context. The rich ecological niche of nematodes like Pristionchus pacificus along with certain properties they possess make them a great system for studying the interactions with their associated microbiota. To determine the complex network of interactions, we predicted the metabolic potential of 84 bacterial strains previously isolated from the nematode's natural environment. The information regarding their metabolic potential as well as associations with nematode traits evaluated in previous studies narrowed down the thousands of metabolic pathways in bacteria to very few potential modulators. To determine whether they played an important role, we generated transcriptomic profiles of the worm from 38 of the strains and constructed a gene co-expression network, the modules of which we proceeded to functionally label. By associating the co-expression modules with the bacterial metabolic potential through a bipartite network, we were able to determine candidate metabolites from the bacteria with an effect on regulatory networks in the nematode.