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Abstract
Environmental contamination is one of the leading ways humans have impacted ecosystems globally. Growing human populations and resulting increases in energy demands have increased the contamination footprint of industry. This increase in industrial activity and energy production has, at times, introduced high levels of radionuclides into the environment that impact both humans and wildlife. Population persistence in such habitats relies on individuals’ ability to acclimate and populations to adapt, yet the health effects and mechanisms of adaptation to elevated ionizing radiation are not well described. In this dissertation I examine genomic, transcriptomic, and parasite infection patterns in two canids, gray wolves and raccoon dogs, from the Chernobyl Exclusion Zone (CEZ) and build a new model system for examining the effects of elevated levels of ionizing radiation. Canids are sentinel species, and ideal model organisms for extrapolating from individual effects to ecological effects, conservation implications, and human health effects. Here I describe population differentiation between wolves from the CEZ and those from northern Belarus. This differentiation, in addition to the negative impacts of elevated radiation exposure, suggest radiation in the CEZ may act as a selective force driving population level differences. To explore individual level implications of exposure, I also describe gene and endogenous retroviral expression patterns which identify regulatory differences associated with immune responses, DNA repair, and cell homeostasis. These patterns are associated with CEZ residency as well as internal radiocesium activity rates. Specifically, multiple genes and genome regulatory patterns are associated with oncogenesis. Interestingly I identified cellular homeostasis and DNA damage genes as genomic regions and candidate genes under selection. Additionally, micro- and macroparasite infection rates within raccoon dogs and wolves from the CEZ help describe the complexity of ecological interactions within a highly contaminated environment. Parasite diversity and prevalence differed between host, parasites, and radiation exposure rates, with only herpes virus and canine parvovirus showing positive correlations with internal radiation activity. Collectively, this work highlights the importance of immune responses, viral infections, and oncogenesis in both detrimental responses as well as potentially stimulating mitigating responses to radiation exposure.