Implications of anthropogenic stressors on rapid coadaptation in a tripartite species interaction

Rapid Evolution
Implications of anthropogenic stressors on rapid coadaptation in a tripartite species interaction
General information
Adaptation and counter-adaptation between two interacting species can be very fast, making species interactions ideal to study rapid coadaptation on contemporary time scales. While both theoretical models and empirical studies deal with dual interactions, data including interactions of more than two species are scarce. However, in a natural scenario, most if not all species interact with more than one species. Therefore, studies that address species interactions in an appropriate biological context with all relevant species involved are urgently needed. We here suggest studying rapid evolutionary adaptation in a three-way host-parasite interaction using an established model system consisting of pipefish Syngnathus typhle (i.e the final animal host), bacteria of the genus Vibrio, and its associated temperate phages (i.e. small viruses that infect Vibrio bacteria). With the ability to integrate into the bacterial genome, phages can provide bacteria with beneficial genes, for instance virulence genes that may increase bacterial genome plasticity and ultimately bacterial fitness. In previous studies we demonstrated by means of experimental coevolution between phages and Vibrio bacteria, that phages rapidly gained the ability to infect resistant Vibrio within 24 hours. Interestingly, this resulted in strong alterations of Vibrio virulence against sympatric pipefish. We now aim to study genotypic and phenotypic patterns and dynamics of rapid adaptation between Vibrio bacteria and phages considering anthropogenic effects that might either constrain or promote species coadaptation. Those anthropogenic impacts include three of the most important threats for marine organisms: bioinvasions, temperature fluctuations, and excessive use of antibiotics. By combining experimental evolution, whole genome sequencing and controlled infection experiments we will address the implications of bioinvasion of temperature heterogeneity and exposure to antibiotics on the coevolutionary dynamics between the three players. In both of these goals the experimental approach will consist of an in vitro description of local adaptation between the players involved. This is followed by experimental evolution and whole genome sequencing to investigate how bioinvasion, temperature fluctuation and exposure to antibiotics affect phage-bacteria adaptation in vitro and how this will correlate with bacterial virulence against local pipefish in vivo. As phages share fundamental factors of pathogens across all kingdoms we offer a highly tractable system to understand rapid pathogen adaptation and in particular constraints of human induced environmental change on rapid species coadaptation.
Start November, 2015 End October, 2018
Funding (total) - Funding (GEOMAR) 236 T€
Funding body DFG Programme Spp 1819
Contact Carolin C. Wendling