abstract
Epigenetic mechanisms are moving to the forefront of environmental sciences, as environmentally induced epigenetic changes shape biological responses to chemical contamination. This work focused on Daphnia as a representative of potentially threatened freshwater biota, aiming to gain an insight into the involvement of epigenetic mechanisms in their response and eventual adaptation to metal contamination. Copper-induced DNA methylation changes, their potential transgenerational inheritance, and life-history traits were assessed. Or-ganisms with different histories of past exposure to copper were exposed to toxic levels of the element for one generation (F0) and then monitored for three subsequent unexposed generations (F1, F2, and F3). Overall, methylation changes targeted important genes for counteracting the effects of metals and oxidative stress, including dynein light chain, ribosomal kinase and nuclear fragile X mental retardation-interacting protein. Also, contrasting overall and gene-specific methylation responses were observed in organisms differing in their history of exposure to copper, with different transgenerational methylation responses being also identified among the two groups, without apparent life-history costs. Taken together, these results demonstrate the capacity of copper to promote epigenetic transgenerational inheritance in a manner related explicitly to history of exposure, thereby supporting the development and incorporation of epigenetic biomarkers in risk assessment frameworks.
keywords
ENVIRONMENTAL EPIGENETICS; DIFFERENTIAL METHYLATION; METAL CONTAMINATION; ECOLOGICAL RISK; GENOME-WIDE; MAGNA; PATTERNS; TOXICITY; GENES; INHERITANCE
subject category
Environmental Sciences & Ecology
authors
Jeremias, G; Veloso, T; Goncalves, FJM; Van Nieuwerburgh, F; Pereira, JL; Asselman, J
Groups
acknowledgements
Acknowledgements We acknowledge the financial support to CESAM by FCT/MCTES (UIDP/50017/2020 + UIDB/50017/2020 + LA/P/0094/2020) through national funds, as well as to BOF/24 J/2021/164 awarded to JA. GJ and TV are grateful to FCT for the awarded individual PhD grants with the references SFRH/BD/139076/2018 and SFRH/BD/147346/2019, respectively.