Evidence of Selective Response in the Free-Breeding Dog Population in Chornobyl.
11 affiliations
- 1Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27607, USA.
- 2Department of Biological Sciences, North Carolina State University, Raleigh, NC 27607, USA.
- 3Visiting Veterinarians International, Damascus, OR 97089, USA.
- 4Clean Futures Fund, Godfrey, IL 62035, USA.
- 5Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA.
- 6Institute for Infectious Disease Translational Research, University of South Carolina, Columbia, SC 29208, USA.
- 7Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY 10032, USA.
- 8Comparative Medicine Institute, North Carolina State University, Raleigh, NC 27607, USA.
- 9Center for Human Health and the Environment, North Carolina State University, Raleigh, NC 27607, USA.
- 10Cancer Genetics, UNC Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA.
- 11Duke Cancer Institute, Duke University, Durham, NC 27710, USA.
Abstract
Background/Objectives: Understanding genomic responses to environmental contamination is essential for assessing long-term ecological and genetic risk. The free-breeding dogs inhabiting the Chornobyl Exclusion Zone (CEZ) offer a unique, multigenerational model for investigating these responses within a chronically contaminated landscape. Following the 1986 radioecological disaster at the Chornobyl Nuclear Power Plant, and subsequent remediation activities, the surrounding environment was contaminated by ionizing radiation, heavy metals, organic compounds, and other environmental toxicants. Our previous work identified significant genetic differentiation between two distinct but geographically proximate dog populations within the CEZ, a pattern not explained by breed composition, spatial isolation, or increased mutation rates. Methods: In this study, we tested the hypothesis that the dogs residing at the nuclear power plant show genomic signatures consistent with adaptive evolution in response to chronic environmental stressors. This work extends prior population-genetic analyses by integrating whole-genome selection scans with estimates of effective population size and comparative measures of population divergence, providing a framework to evaluate whether the observed genomic differentiation is more consistent with selection than demography. Using these whole genomic data, we evaluated chromosome-level FST metrics, estimated effective population size (Ne), and analyzed a geographically isolated island dog population as a comparative reference for genetic divergence. Results: We continued to find that the levels of genetic differentiation are not comparable to other free-breeding dog populations. Genome-wide outlier analyses identified candidate loci showing evidence of positive selection across multiple metrics. Conclusions: Genes associated with these loci were enriched for biological functions related to DNA replication and repair, cell death and survival, cellular compromise, immune response, and cancer-associated pathways, suggesting biologically plausible mechanisms through which chronic environmental stress could influence fitness. These findings are consistent with directional selection in the nuclear power plant population, which could potentially be associated with the environmental variables present, and advance our understanding of local adaptation and genomic resilience under chronic environmental contamination.
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BibTeX
@article{dillon2026evidence,
title = {{Evidence of Selective Response in the Free-Breeding Dog Population in Chornobyl.}},
author = {Megan N Dillon and Reade B Roberts and Jennifer A Betz and Timothy A Mousseau and Norman J Kleiman and Matthew Breen},
journal = {Genes},
year = {2026},
month = sep,
doi = {10.3390/genes17101195},
url = {https://europepmc.org/article/MED/42938311},
note = {CC BY},
}
RIS
TY - JOUR
TI - Evidence of Selective Response in the Free-Breeding Dog Population in Chornobyl.
AU - Megan N Dillon
AU - Reade B Roberts
AU - Jennifer A Betz
AU - Timothy A Mousseau
AU - Norman J Kleiman
AU - Matthew Breen
PY - 2026
DA - 2026/09/27
JO - Genes
DO - 10.3390/genes17101195
UR - https://europepmc.org/article/MED/42938311
AB - Background/Objectives: Understanding genomic responses to environmental contamination is essential for assessing long-term ecological and genetic risk. The free-breeding dogs inhabiting the Chornobyl Exclusion Zone (CEZ) offer a unique, multigenerational model for investigating these responses within a chronically contaminated landscape. Following the 1986 radioecological disaster at the Chornobyl Nuclear Power Plant, and subsequent remediation activities, the surrounding environment was contaminated by ionizing radiation, heavy metals, organic compounds, and other environmental toxicants. Our previous work identified significant genetic differentiation between two distinct but geographically proximate dog populations within the CEZ, a pattern not explained by breed composition, spatial isolation, or increased mutation rates. Methods: In this study, we tested the hypothesis that the dogs residing at the nuclear power plant show genomic signatures consistent with adaptive evolution in response to chronic environmental stressors. This work extends prior population-genetic analyses by integrating whole-genome selection scans with estimates of effective population size and comparative measures of population divergence, providing a framework to evaluate whether the observed genomic differentiation is more consistent with selection than demography. Using these whole genomic data, we evaluated chromosome-level FST metrics, estimated effective population size (Ne), and analyzed a geographically isolated island dog population as a comparative reference for genetic divergence. Results: We continued to find that the levels of genetic differentiation are not comparable to other free-breeding dog populations. Genome-wide outlier analyses identified candidate loci showing evidence of positive selection across multiple metrics. Conclusions: Genes associated with these loci were enriched for biological functions related to DNA replication and repair, cell death and survival, cellular compromise, immune response, and cancer-associated pathways, suggesting biologically plausible mechanisms through which chronic environmental stress could influence fitness. These findings are consistent with directional selection in the nuclear power plant population, which could potentially be associated with the environmental variables present, and advance our understanding of local adaptation and genomic resilience under chronic environmental contamination.
SN - 2073-4425
ER -