Mercury-associated DNA hypomethylation in polar bear brains via the LUminometric Methylation Assay: a sensitive method to study epigenetics in wildlife

• Published in: Molecular Ecology
• Main Authors: Richard pilsner, J., Lazarus, Alicia L., Nam, Dong-Ha, Letcher, Robert J., Sonne, Christian, Dietz, Rune, Basu, Niladri
• Other Authors: Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, MI 48109, USA, Department of Epidemiology, Environment Canada, National Wildlife Research Center, Carleton University, Ottawa, ON K1A 0H3, Canada, National Environmental Research Institute, University of Aarhus, Frederiksborgvej 399, DK-4000 Roskilde, Denmark
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Blackwell Publishing Ltd 2010
• Subjects: DNA Methylation; Ecotoxicology; Epigenetics; Neurotoxicology; Wildlife; Ecology and Evolutionary Biology; Science; Greenland; East Greenland; polar bear
• Online Access: http://hdl.handle.net/2027.42/78717; https://doi.org/10.1111/j.1365-294X.2009.04452.x

In this paper we describe a novel approach that may shed light on the genomic DNA methylation of organisms with non-resolved genomes. The LUminometric Methylation Assay (LUMA) is permissive for genomic DNA methylation studies of any genome as it relies on the use of methyl-sensitive and -insensitive restriction enzymes followed by polymerase extension via Pyrosequencing technology. Here, LUMA was used to characterize genomic DNA methylation in the lower brain stem region from 47 polar bears subsistence hunted in central East Greenland between 1999 and 2001. In these samples, average genomic DNA methylation was 57.9% ± 6.69 (SD; range was 42.0 to 72.4%). When genomic DNA methylation was related to brain mercury (Hg) exposure levels, an inverse association was seen between these two variables for the entire study population ( P for trend = 0.17). After dichotomizing animals by gender and controlling for age, a negative trend was seen amongst male animals ( P for trend = 0.07) but no associations were found in female bears. Such sexually dimorphic responses have been found in other toxicological studies. Our results show that genomic DNA methylation can be quantitatively studied in a highly reproducible manner in tissue samples from a wild organism with a non-resolved genome. As such, LUMA holds great promise as a novel method to explore consequential questions across the ecological sciences that may require an epigenetic understanding. Peer Reviewed http://deepblue.lib.umich.edu/bitstream/2027.42/78717/1/j.1365-294X.2009.04452.x.pdf