Advances in Age Estimation Based on DNA Methylation for Wildlife Conservation

抄録

　Understanding aging in wild animals is fundamental to effective conservation, yet accurately determining age in free-ranging individuals remains a major challenge. While DNA provides stable genetic information for species identification, kinship and population structure, its sequence does not directly reflect age. Recent advances in epigenetics, particularly DNA methylation analysis, have enabled age estimation based on predictable, age-associated changes in gene regulation, offering a powerful alternative to traditional methods. Here, we review the development and application of DNA methylation-based age estimation across diverse animal taxa. We compare methodological approaches ranging from targeted techniques, such as methylation-sensitive high-resolution melting (MS-HRM), to genome-wide methods including reduced representation bisulfite sequencing (RRBS) and array-based platforms, highlighting their respective trade-offs in resolution, cost and scalability. We also examine how age estimation models are developed using known-age individuals and subsequently applied to wild populations using less-invasive samples such as feces, hair or feathers. Importantly, DNA methylation reflects not only chronological age but also aspects of biological aging, including physiological condition and environmental exposure. Integrating epigenetic age data into ecological frameworks can improve the estimation of population age structure and enhance demographic models. Overall, DNA-methylation-based age estimation represents a powerful bridge between molecular biology and conservation, providing new opportunities to better understand and manage wildlife populations in a rapidly changing world.