Metabolic Mechanisms of (Photo)Synthetic Symbiosis

BACKGROUND: The chloroplast originated when, some 600-1600 million years ago, a eukaryotic cell engulfed a free-living cyanobacterium. While comparative genomics provides a picture of the end-products of this event, it is not possible by this approach to recapitulate and understand those events in deep evolutionary time which stabilised this important endosymbiosis. This project will take an experimental approach, engineering a synthetic symbiosis between a single-celled eukaryote and a cyanobacterium, to resolve by genetics, modelling and single-cell metabolomics the metabolic underpinnings of the origination of a photosynthetic endosymbiosis.

OBJECTIVES: This project builds on an on-going NERC-funded project (2014-2017) using experimental coevolution to study the real-time coevolutionary dynamics of the eukaryote-cyanobacterium synthetic symbiosis, but goes beyond the remit of the NERC study to resolve the evolved metabolic mechanisms of stable endosymbiosis. Specifically the project will:
1. Construct mechanistic models of cyanobacterial metabolic evolution in endosymbiosis using flux-balance analysis validated by single-cell metabolomics
2. Resolve the genetic architecture and mechanisms of cyanobacterial adaptation to endosymbiosis by reconstructing genotypes derived from experimental evolution to test the individual and epistatic effects of beneficial mutations on fitness and metabolism

NOVELTY/TIMELINESS: This project is at the cutting-edge of symbiosis research, and takes a novel synthetic symbiosis approach to studying the important but rare major endosymbiosis events of deep evolutionary time.
It applies state-of-the-art computational and metabolomics technologies to understand the metabolic mechanisms of endosymbiosis.