A genetic study conducted by the University of South Carolina and the National Human Genome Research Institute, published in Science Advances, has uncovered that dogs living within the Chernobyl exclusion zone (CEZ) show distinct genetic changes linked to long-term radiation exposure. Researchers analyzed the DNA of 302 feral dogs from the CEZ and compared it to populations outside the zone, revealing significant genetic divergence that may influence their survival and reproduction.
Living With Radiation Has Altered Their DNA
The study identified genomic regions associated with radiation response, including loci linked to DNA repair, immune function, and metabolic regulation. Variants in genes such as ATM, TP53, and XRCC4, all critical in repairing DNA double-strand breaks, were found at different frequencies in CEZ dog populations compared to controls.
A chart from the study (see below) illustrates genetic distance (Fst scores) between CEZ populations and those 16 kilometers away, with peaks at specific chromosomal regions:
Chromosome | Peak Fst Score | Associated Gene
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Chr 6 | 0.42 | ATM
Chr 11 | 0.39 | TP53
Chr 20 | 0.35 | XRCC4 These differences suggest selective pressure favoring alleles that may enhance survival in environments with chronic low-dose radiation exposure.
Reduced Diversity and Isolated Gene Pools
The analysis also showed lower heterozygosity among dogs living closest to the Chernobyl plant, consistent with small founding populations and limited breeding opportunities. The study’s principal component analysis (PCA) chart highlighted distinct clustering of CEZ dogs versus those from Chernobyl city and surrounding villages.
This genetic isolation may be contributing to the fixation of radiation-tolerant traits, though researchers note that inbreeding could also reduce resilience to disease and other pressures.
Evidence of Rapid Evolutionary Change
Beyond DNA repair genes, variants linked to melanin production—such as changes in the MC1R gene—were enriched in CEZ dogs, potentially explaining reports of darker coat pigmentation. This mirrors adaptations seen in local frog populations, where increased melanin may reduce oxidative damage from radiation.
The study also detected positive selection signals in genes involved in immune regulation (TLR4) and oxidative stress response (SOD2). These pathways are critical for coping with chronic environmental insults, suggesting the dogs’ immune systems may be adapting to persistent radiation and contamination.
Why This Matters
By mapping these genetic differences, scientists can better understand how wildlife adapts to extreme environments. Dr. Elaine Ostrander emphasized that the CEZ serves as “a rare chance to observe evolutionary processes in real time.”
This knowledge could extend to human health: the same pathways observed in these dogs are linked to cancer susceptibility and resilience to radiation therapy. Future research will sequence larger sample sizes over time to confirm whether these genetic changes translate into measurable differences in survival and reproduction.