We think we know what causes mutations in dogs at Chornobyl, right?
Megan Dillon, PhD graduate from the Genetics program at North Carolina State University, says that might not be the case.
Megan is a recent PhD graduate from the Genetics program at North Carolina State University. Her dissertation work focused on the free-breeding dogs that live around the Chornobyl Nuclear Power Plant. The project has caught the attention of many around the world and resulted in four publications since 2023, the newest of which describes the group’s analysis into mutation and is available through PLoS One (https://doi.org/10.1371/journal.pone.0315244).
The Dogs of Chornobyl
The 1986 disaster at the Chornobyl Nuclear Power Plant was an extreme environmental catastrophe. Many will recognize it as the largest nuclear disaster in history, but other environmental toxicants and mutagenic compounds were also released into the environment, including heavy metals and pesticides. Many wildlife species still remain in the area around the Chornobyl Nuclear Power Plant, along with hundreds of free-breeding dogs. With our work, we are focused on assessing how the multi-generational exposure to the contamination at Chornobyl has impacted these dog populations. Previously, we found that the population of dogs that live around the Nuclear Power Plant were genetically differentiated from comparison populations elsewhere in Ukraine and Eastern Europe. With our latest study, we looked for evidence of increased mutation in these Chornobyl dogs by studying the chromosome structure for evidence of abnormalities, studying short repeated sequences in the DNA for increased diversity, and studying DNA bases for evidence of more recent substitutions. Interestingly, we do not find evidence that increased mutation in this dog population is driving this genetic divergence that we identified. Our work actually recapitulates the findings of a similar study conducted in humans, which also did not identify increased mutation rates in children born to the Chornobyl liquidators. We have yet to definitively identify the cause for the genetic differentiation of the Nuclear Power Plant population of dogs, but the findings of our first study suggested that natural selection could be playing a role. With our current work, we are considering whether a strong selective response could have driven the genetic divergence of this dog population, as we continue to address the genetic consequences of the environmental contamination.
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