Spatial dynamics of synthetic microbial mutualists and their parasites
Amor, D.R.; Montañez, R.; Duran-Nebreda, S., Solé, R. (2017)
PLoS Computational Biology 13(8): e1005689. https://doi.org/ 10.1371/journal.pcbi.1005689
A key innovation in evolution is the emergence of cooperative systems from competing interactions. By using theoretical models, it has been shown that the cost of such cooperative systems is compensated by their resilience against parasites when they grow in a spatial context. Can these ideas be tested experimentally? To find out, a microbial ecosystem was engineered which incorporated both symbiotic interactions using two designed strains that required each other to grow. This cooperative loop pervades the emergence of some types of symbiotic relationships and enables the exploration of the conditions for the rise and fall of cooperation. These populations grow in a spatial domain (a Petri dish) and can be threatened by a synthetic parasite, which was also designed, to study the role played by spatial constraints. This paper shows that space does indeed play a crucial role in preventing the invasion of parasites, and also how some types of parasites can turn into cooperating species under determined environmental conditions.