Mutually beneficial species interactions are universal in natural ecosystems, including agriculture and the human microbiome. Mutualism enables the exchange of resources and, combined with a changing environment, is hypothesized to drive inter-species co-evolution. However, the molecular mechanisms that link mutualism to evolution are lacking. Xindan Wang, in collaboration with Cari Vanderpool and Katy Heath, will utilize the mutualism of legume and nitrogen-fixing rhizobia to understand the molecular basis for evolutionary differentiation through the lens of genome architecture and gene expression. The project aims to investigate the genome architecture of rhizobia variants that have differential symbiosis ability with clover by performing genome-wide chromosome conformation capture assays (Hi-C) on rhizobia strains with different genome rearrangements. Furthermore, they strive to understand the alteration of gene expression in the evolved rhizobia strains via RNA-seq experiments in the strains with differential symbiotic abilities. This collaborative project will address the Rules of Engagement theme in GEMS and result in the development of molecular tools to study genome conformation and gene expression that can be used in other model systems.