7 Evolution in Heritable Bacterial–Fungal Endosymbioses

Recent accumulation of data from newly discovered bacterial–fungal symbioses revealed that many of these associations are suitable as models to understand evolution of symbioses in general. Thus far, alliances formed by early divergent lineages of Mucoromycotina and Glomeromycota with heritable beta-proteobacteria and Mollicutes yielded novel insights into the forms of evolutionary trajectories in mutualisms and into mechanisms of symbiont genome evolution. Future work is expected to reveal molecular underpinnings of symbiont vertical transmission and forces that drive coevolution between the partners.