Weitz Group @ Georgia Tech Theoretical Ecology and Quantitative Biology

Meta-analysis reveals hidden nested pattern in host-phage interactions (Flores et al., PNAS 2011)

Posted by jsweitz

Bacteria and the viruses (i.e. phages) that infect them are two of the most numerically abundant and genetically diverse groups of organisms, as revealed by recent innovations in environmental genomics. Yet, despite their numerical dominance, our understanding of these microbes lags in many areas, including their most basic ecology of who interacts with whom. This deficit is unfortunate given that bacteria-phage interactions are important for both human health and global ecosystem function.

We performed a comprehensive meta-analysis of the structure of bacteria-phage interaction networks. We compiled 38 studies that characterized host-phage infections and asked if these interaction networks have a nonrandom structure, if they conform to a characteristic shape, or if they are idiosyncratic and hard to predict. We found that the majority of the host-phage infection patterns we examined were nested, nonrandom, and not “compartmentalized”. We examine possible biophysical, ecological and evolutionary mechanisms underlying the finding of nestedness within host-phage interaction networks. We also propose that host-phage infection structure will exhibit increasingly compartmentalized infection patterns when examining interactions of more distantly related species. Our study complements the accumulation of microbial community genomic information by answering these questions on host-phage interactions with a large-scale meta-analysis of functional data.