DNA methylation and mercury in Polar Bears

This study used a LuMA-based approach to look at DNA methylation and mercury levels in polar bear brains. Mercury is a pollutant that gets amplified up the food chain, making animals like the endangerred polar bear highly susceptible to detrimental effects. Looking at mercury's effects on genetic expression, however, is impeded because the polar bear genome is unresolved. The LuMA approach uses methyl-sensitive restriction enzymes followed by bioluminometric PCR (a quantitative method). This yields information about relative methylation of the genome between "experimental" groups, but yields no functional information. These researchers found that brain stem mercury had an inverse relationship with global DNA methylation in male bears, but no effect was found in female bears. Global hypomethylation of the genome has been linked to genomic instability, and could render these animals even more at risk to the effects of climatic instability and habitat degradation.