Gene

Ecology

Biology

Epigenetics

Fish <Actinopterygii>

Fishery

Daphnia magna

Salinity

Transgenerational epigenetics

DNA methylation

Daphnia

Evolutionary biology

Environmental stress

Genetics

Organic chemistry

Killifish

Embryo

Inheritance (genetic algorithm)

Toxicity

Parthenogenesis

Chemistry

Zoology

Crustacean

Gene expression

Ecosystem

Environmental Science & Technology

Epigenetic mechanisms have been found to play important roles in environmental stress response and regulation. These can, theoretically, be transmitted to future unexposed generations, yet few studies have shown persisting stress-induced transgenerational effects, particularly in invertebrates. Here, we focus on the aquatic microcrustacean Daphnia, a parthenogenetic model species, and its response to salinity stress. Salinity is a serious threat to freshwater ecosystems and a relevant form of environmental perturbation affecting freshwater ecosystems. We exposed one generation of D. magna to high levels of salinity (F0) and found that the exposure provoked specific methylation patterns that were transferred to the three consequent nonexposed generations (F1, F2, and F3). This was the case for the hypomethylation of six protein-coding genes with important roles in the organisms' response to environmental change: DNA damage repair, cytoskeleton organization, and protein synthesis. This suggests that epigenetic changes in Daphnia are particularly targeted to genes involved in coping with general cellular stress responses. Our results highlight that epigenetic marks are affected by environmental stressors and can be transferred to subsequent unexposed generations. Epigenetic marks could therefore prove to be useful indicators of past or historic pollution in this parthenogenetic model system. Furthermore, no life history costs seem to be associated with the maintenance of hypomethylation across unexposed generations in Daphnia following a single stress exposure.

Transgenerational Inheritance of DNA Hypomethylation in <i>Daphnia magna</i> in Response to Salinity Stress

Transgenerational Inheritance of DNA Hypomethylation in Daphnia magna in Response to Salinity Stress