Epigenetics in an ecotoxiological context

Epigenetics in an ecotoxiological context

mutation researchChildren of obese fathers are more likely to have chronic diseases in their later life. That was the conclusion of a remarkable study by Dr. Adelheid Soubry in BMC Medicine (De Standaard, 08/02/2013). She identified one of the mechanisms responsible to be DNA-methylation. DNA-methylation, among other mechanisms, are so-called epigenetic mechanisms. They can alter the DNA without actually altering the DNA code itself. These epigenetic mechanisms are also shown to be important in an ecotoxicological context. This was recently summarized by our post-doc Michiel Vandegehuchte in a review in Mutation Research/Genetic Toxicology and Environmental Mutagenesis.


Scientific abstract

Epigenetics can play a role in interactions between chemicals and exposed species, between species and abiotic ecosystem components or between species of the same or another population in a community. Technological progress and advanced insights into epigenetic processes have led to the description of epigenetic features (mainly DNA methylation) in many ecologically relevant species: algae, plants, several invertebrates and fish. Epigenetic changes in plants, insects and cladocerans have been reported to be induced by various environmental stress factors including nutrition or water deficiency, grazing, light or temperature alterations, social environment, and dissolved organic matter concentrations. As regards chemicals, studies in rats and mice exposed to specific pesticides, hydrocarbons, dioxins, and endocrine disrupting chemicals demonstrated the induction of epigenetic changes, suggesting the need for further research with these substances in an ecotoxicological context. In fish and plants, exposure to polyaromatic hydrocarbons, metals, and soluble fractions of solid waste affected the epigenetic status. A novel concept in ecotoxicological epigenetics is the induction of transgenerational stress resistance upon chemical exposure, as demonstrated in rice exposed to metals. Evaluating epigenetics in ecotoxicological field studies is a second relatively new approach. A cryptic lineage of earthworms had developed arsenic tolerance in the field, concurrent with specific DNA methylation patterns. Flatfish caught in the framework of environmental monitoring had developed tumours, exhibiting specific DNA methylation patterns. Two main potential implications of epigenetics in an ecotoxicological context are (1) the possibility of transgenerationally inherited, chemical stress-induced epigenetic changes with associated phenotypes and (2) epigenetically induced adaptation to stress upon long-term chemical exposure. Key knowledge gaps are concerned with the causality of the relation between epigenetic and phenotypic changes, the persistence of transgenerational effects, the implications at population level and the costs of tolerance. Epigenetic changes following exposure to multiple stressors constitute another promising area of further research.


Full reference

Vandegehuchte M, Janssen CR. 2013. Epigenetics in an ecotoxicological context. Mutation Research/Genetic Toxicology and Environmental Mutagenesis. In press. DOI: 10.1016/j.mrgentox.2013.08.008.