Dear MARMAM members, On behalf of all the authors, I would like to share with you our last paper published in Marine Genomics: “Skin distress associated with xenobiotics exposure: An epigenetic study in the Mediterranean fin whale (Balaenoptera physalus)” Authors: Annalaura Mancia, Luigi Abelli, Maria Cristina Fossi, Cristina Panti https://doi.org/10.1016/j.margen.2020.100822 The publication can be found at: https://www.sciencedirect.com/science/article/pii/S1874778720300830 Abstract: The phenotypic plasticity of many organisms is mediated in part by epigenetics, the heritable changes in gene activity that occur without any alterations to DNA sequence. A major mechanism in epigenetics is the DNA methylation (DNAm). Hypo- and hyper-methylation are generalized responses to control gene expression however recent studies have demonstrated that classes of contaminants could mark specific DNAm signatures, that could usefully signal prior environmental exposure. We collected skin and blubber from 6 free-ranging fin whale (Balaenoptera physalus) individuals sampled as a part of a previous published study in the northern Mediterranean Sea. Genomic DNA extracted from the skin of the fin whales and levels of contaminants measured in the blubber of the same individuals were used for DNAm profiling through reduced representation bisulfite sequencing (RRBS). We tested the hypothesis that differences in the methylation patterns could be related to environmental exposure to contaminants and load in the whale tissues. The aims of this study were to determine the DNAm profiles of the methylation contexts (CpGs and non-CpGs) of differently contaminated groups using the RRBS, and to identify potential contaminant exposure related genes. Amount and proportion of methylcytosines in CpG and non-CpG regions (CHH and CHG) was very similar across the 6 samples. The proportion of methylcytosines sites in CpG was n = 32,682, the highest among all the sequence contexts (n = 3216 in CHH; n = 1743 in CHG). The majority of the methylcytosine occurred in the intron regions, followed by exon and promoter regions in CpG, CHH and CHG. Gene Ontology results indicated that DNAm affected genes that take place in cell differentiation and function in cutaneous, vascular and nervous systems. The identification of cellular response pathways allows a better understanding of the organism biological reaction to a specific environmental challenge and the development of sensitive tools based on the predictive responses. Eco-epigenetics analyses have an extraordinary potential to address growing issues on pollution biomonitoring, ecotoxicity assessment, conservation and management planning. Thank you for your interest in the paper! Best regards, Cristina
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Cristina Panti, PhD Department of Environmental, Earth and Physical Sciences University of Siena Via P.A. Mattioli, 4 53100, Siena Italy Ph. +39 0577 232245 Fax. +39 0577 232930 https://plasticbustersmpas.interreg-med.eu/ https://www.unisi.it/