The MultiOmicsTox project focused on the utilization of multi-omics data obtained from a Daphnia population from Lake Ring, a well-characterized Danish lake in central Jutland. This lake has a historical record spanning 120 years, during which it underwent various pollution events such as eutrophication caused by sewage inflows, pesticide contamination from agricultural run-off, and subsequent recovery. The project specifically examined the response of Daphnia populations of genetically distinct genotypes, derived from identical clones to pesticide exposure.
The ecological history of the four Daphnia sub-populations in Lake Ring is well-documented. Through radiometric chronology and paleolimnological analysis of sediment, it was determined that the lake was relatively pristine until the late 1950s. Subsequently, human activities led to eutrophication and the introduction of pesticides, primarily carbamates, into the lake through agricultural run-off. From 1999 onwards, the lake has shown significant recovery from eutrophication and pesticide toxicity, indicating reduced land use in modern times. To capture the different ecological phases, genetically distinct lines of Daphnia sub-populations were established at the University of Birmingham, representing the pristine, eutrophication, pesticide, and recovery phases.
Genome analysis of the Lake Ring Daphnia revealed the impact of eutrophication and pesticides on the genetic diversity of the population, highlighting potential targets of natural selection in response to environmental changes. Transcriptomic analysis demonstrated context-dependent changes in pesticide response at both individual and sub-population levels. The project successfully identified potential novel candidate gene regulatory networks and potential toxicity pathways, shedding light on adaptive changes and their association with adverse outcome pathways.
While the model chemical insecticide used in this study was banned in European markets, the genes and gene regulatory networks uncovered hold promise as biomarkers for other pesticides with similar modes of action. These biomarkers have the potential to assess the impact of chemical exposure and monitor its effects on susceptible populations.
Continued sharing of the findings and insights from this research with various stakeholders can potentially contribute to regulatory decision-making processes. This includes supporting the development of targeted monitoring strategies and the implementation of appropriate mitigation measures to safeguard human health and the environment.
