Meeting Abstract
Methylmercury (MeHg) is a highly toxic global pollutant that affects human, wildlife, and ecosystem health. This heavy metal compound can successfully cross the blood brain barrier and is capable of inducing oxidative stress in the formation of free radicals. Organs such as the liver and kidney, which play large roles in the excretory system, may be overwhelmed by the cellular damage caused by exposure to MeHg due to their functional role. Further understanding of how MeHg exposure alters organ performance at a cellular level is critical to understanding physiological effects this toxin can have on both humans and wildlife impacted by environmental contamination. Telomere length is a recently popularized biomarker of biological aging and cellular damage, influenced by both genetics and environment. To assess the impact of MeHg on eukaryotic organisms, we studied how lifetime exposure to dietary MeHg impacts telomere length in various tissues of the zebra finch (Taeniopygia guttata) at four time points after hatching from eggs. Using qPCR, we measured relative telomere lengths of brain, liver, kidney, heart, and red blood cells. We predicted that telomere length would decrease with the age of birds, and individuals exposed to an environmentally relevant level of dietary MeHg would have reduced telomere lengths compared to controls. Although blood telomere length clearly declined with age as predicted, we found that mercury-exposed birds had consistently longer telomere lengths in virtually all tissues and time points relative to controls. This latter result suggests the potential selection for longer telomeres within embryos (before egg hatching) and/or disruption of the telomerase pathway by MeHg.
