Chemikalien und ökologisch-evolutionäre Dynamik prägen die Gemeinschaften
Zusammenfassung der Projektergebnisse
Microbial communities are dominated by species interactions and coevolution, which respond to changes in the interplay of ecological and evolutionary processes. These ecoevolutionary processes can be altered when communities are exposed to chemicals. This project aimed to study how coevolutionary dynamics of tripartite microbial system consisting of a heterotrophic flagellate, a giant virus and a virophage are affected when exposed to Predicted No Effect Concentrations (PNEC) of an antiviral. The giant virus parasitizes the host, while the virophage parasitizes the giant virus inhibiting its replication what favors host population survival. Virophage can also integrate into the host genome and being reactivated after host infection with the giant virus. Previous experiments without antiviral stress show coexistence and populations coevolution. Here, we compared ecological and evolutionary changes of communities for ~ 280 host generations when exposed to a single pulse, continues exposure and no exposure of the antiviral. We observed that population sizes and dynamics differ between communities, however, allowing coexistence in both the presence and absence of the antiviral. Host isolated from the end of the experiment survived virus infections and this was most pronounced for those isolated that were continuously exposed to the antiviral. Virus and virophage trait changed, virus evolved towards lower levels of replication and virophage evolved towards higher replication, higher integration rate in the host genome but lower inhibition of the virus. To conclude, even PNEC of an antiviral agent has the potential to interfere microbial interactions by altering population size and populations coevolution, which alter the form of symbiosis. Results of this project have contributed to new knowledge on the ecological and evolutionary significance of natural population dynamics to understand community responses to their environment what is especially relevant to enrich environmental education programs. It is a central base to empower societies for more ecologically, economically sustainable and equitable environmental decision-making. Advancing the understanding of species interactions, dynamics and coevolution bring about new knowledge on community structure, function and diversity. Specifically, the host-virus-virophage microbial community is valuable beyond its potential practical use as a control agent. For instance, viral infection plays a role in biogeochemical nutrient cycling and also influences the ecology of the host as a grazer in the community. Therefore, the study of this microbial community brings knowledge on community ecology.
Projektbezogene Publikationen (Auswahl)
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Building up chemostats for experimental eco-evolutionary studies v2.
Del Arco, Ana; Woltermann, Noemi & Becks, Lutz
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Simultaneous Giant Virus and Virophage Quantification Using Droplet Digital PCR. Viruses, 14(5), 1056.
del Arco, Ana; Fischer, Matthias & Becks, Lutz
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Evolution of exploitation and replication of giant viruses and virophages. Virus Evolution, 10(1).
del Arco, Ana; Fischer, Matthias G. & Becks, Lutz
