Revisiting the genotoxic syndrome: Why are we overlooking the ecological impacts of genotoxins on animal populations?

Cancer, neurodegeneration and other chronic diseases have been a primary focus for researchers studying the effects of genotoxins on human populations. However, when the scope shifts to non-human animals in natural environments, the impact of genotoxins extends beyond aging-related diseases. In ecological studies, DNA damage biomarkers (e.g., fragmentation of genetic material, micronuclei) in animal populations are often used to indicate "environmental quality", but usually with a focus on human health. For example, an increase in the micronuclei frequency in an animal (sentinel) population may indicate risks to the genomic stability of the human population living in the same environment. This human-oriented approach frequently overlooks the ecological impacts of genotoxins on animal populations as an end, limiting the benefits for nature conservation from geno-toxicological studies. Environmental genotoxins pose a significant threat to biodiversity by causing multiple classes of DNA damage and mutations that impair varied cellular functions and reproduction, ultimately jeopardizing species survival through non-carcinogenic processes. This phenomenon, termed "genotoxic syndrome", will be revisited in this article with examples of its detrimental effects on non-human animal populations. Finally, challenges and opportunities in evaluating genotoxic syndrome and its importance for conservation strategies are also discussed.