Ecotoxicity of metal mixtures on aquatic communities: something out of the blue?

The project will study the interplay between the gut microbiome and epigenetic modifications in response to stress by using the water flea Daphnia magna in combination with the cyanobacterium Microcystis aeruginosa as a model system. From our previous research, we know that both the gut microbiome and the epigenome are involved in the stress response of Daphnia sp. to Microcystis sp. Yet the lack of a combined integrative approach makes it impossible to establish causal links between the different levels of regulation (e.g. gut microbiome, epigenome). Thus, this project will focus on an integrative mechanistic approach to unravel the contributions of both the epigenome and gut microbiome. We will use a multi-omics approach studying the gut microbiome, microbial transcriptome, Daphnia epigenome and Daphnia transcriptome in susceptible and resistant D. magna genotypes to M. aeruginosa stress. We will focus on tissue specific patterns of the gut, an innovative approach allowing us to detect expression patterns inherent to the gut which may have been obscured in previous research at the whole body level. The project will also test the proposed mechanisms at the higher phenotypic levels by studying enzyme and protein activity. Therefore, this project will be the first to comprehensively elucidate the key factors contributing to Microcystis resistance in D. magna and serve as a model approach on how to study interactions between host epigenomes and gut microbiomes.