title: DNA methyltransferases and stress-related genes expression in zebrafish larvae after exposure to heat and copper during reprogramming of DNA methylation.
abstract: DNA methylation, a well-studied epigenetic mark, is important for gene regulation in adulthood and for development. Using genetic and epigenetic approaches, the present study aimed at evaluating the effects of heat stress and copper exposure during zebrafish early embryogenesis when patterns of DNA methylation are being established, a process called reprogramming. Embryos were exposed to 325 μg Cu/L from fertilization (<1 h post fertilization - hpf) to 4 hpf at either 26.5 °C or 34 °C, followed by incubation in clean water at 26.5 °C till 96 hpf. Significant increased mortality rates and delayed hatching were observed following exposure to combined high temperature and Cu. Secondly, both stressors, alone or in combination, significantly upregulated the expression of de novo DNA methyltransferase genes (dnmt3) along with no differences in global cytosine methylation level. Finally, Cu exposure significantly increased the expression of metallothionein (mt2) and heat shock protein (hsp70), the latter being also increased following exposure to high temperature. These results highlighted the sensitivity of early embryogenesis and more precisely of the reprogramming period to environmental challenges, in a realistic situation of combined stressors.
authors.affiliation: Research Unit in Environmental and Evolutionary Biology, University of Namur, Rue de Bruxelles 61, B-5000 Namur, Belgium.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Dorts
authors.affiliation: Research Unit in Environmental and Evolutionary Biology, University of Namur, Rue de Bruxelles 61, B-5000 Namur, Belgium.
authors.forename: Elodie
authors.initials: E
authors.lastname: Falisse
authors.affiliation: Research Unit in Environmental and Evolutionary Biology, University of Namur, Rue de Bruxelles 61, B-5000 Namur, Belgium.
authors.forename: Emilie
authors.initials: E
authors.lastname: Schoofs
authors.affiliation: Research Unit in Environmental and Evolutionary Biology, University of Namur, Rue de Bruxelles 61, B-5000 Namur, Belgium.
authors.forename: Enora
authors.initials: E
authors.lastname: Flamion
authors.affiliation: Research Unit in Environmental and Evolutionary Biology, University of Namur, Rue de Bruxelles 61, B-5000 Namur, Belgium.
authors.forename: Patrick
authors.initials: P
authors.lastname: Kestemont
authors.affiliation: Research Unit in Environmental and Evolutionary Biology, University of Namur, Rue de Bruxelles 61, B-5000 Namur, Belgium.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Silvestre
mesh_terms: D000818:Animals; D003300:Copper / Q000494:pharmacology*; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000096:biosynthesis*; D019175:DNA Methylation / Q000187:drug effects*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D018869:Heat-Shock Response / Q000187:drug effects*; D006358:Hot Temperature; D015027:Zebrafish / Q000378:metabolism*; D029961:Zebrafish Proteins / Q000096:biosynthesis*
chemical_list: D029961:Zebrafish Proteins; D003300:Copper; D004248:DNA (Cytosine-5-)-Methyltransferases