Limitations of the reactive‑oxygen‑species dogma and bottlenecks in mitochondrial genome analysis The accumulation of mutations in mitochondrial DNA (mtDNA), which governs intracellular energy metabolism, is a central hallmark of chronic aging that drives metabolic decline and cell death. Conventional biological guidelines have regarded oxidative damage caused by reactive oxygen species (ROS) leaking from the mitochondrial electron‑transport chain as the primary source of genomic mutations. However, this model fails to explain why mutations surge asymmetrically at specific nucleotide positions and why antioxidant supplementation does not prevent mtDNA genome degradation. The inability to pinpoint the fundamental mechanisms underlying sequence variation has long impeded the design of effective anti‑aging molecular targets.

Discovery of passenger mutations through large‑cohort analysis In the study published in Nature on 27 May, we analyzed whole‑genome sequencing (WGS) data from a massive cohort comprising thousands of human blood samples across all ages to overcome these barriers. The team deployed an ultra‑sensitive single‑base heterogeneity detection algorithm to extract ultra‑low‑frequency mutation spectra that are typically obscured in standard sequencing data. This approach demonstrated at the molecular level that the dynamic mutation patterns concealed within mtDNA are not footprints of external oxidative stress but rather permanently fixed ‘cryptic replication errors’ arising from mitochondrial replication machinery faults.

Age‑dependent somatic mosaicism and clonal expansion Dynamic tracking of genetic trajectories revealed that replication‑error markers arising probabilistically during early development and differentiation persist in cells as low‑penetrance ‘passenger mutations’ across the nucleotide sequence. As individuals age and cells undergo division, these markers experience spatiotemporal drift, leading to the expansion of mitochondrial subpopulations harboring specific mutations and driving ‘age‑related somatic mosaicism’ throughout tissues. The team provided quantitative molecular biophysical curves showing that the intrinsically low‑frequency replication‑error‑derived mutation spectrum becomes statistically detectable at the population level with advancing age.

Paradigm shift in anti‑aging research and establishment of molecular diagnostic standards The systems‑genetics data provide new direction for next‑generation biotech drug development and digital health enterprises. They enable a full transition of aging‑intervention guidelines from generic antioxidant administration to a ‘Pol γ replication‑integrity correction and error‑threshold control system.’ The generated mtDNA replication‑error map serves as the standard for next‑generation liquid‑biopsy companion‑diagnostic (CDx) engines that compute a fine‑scale mitochondrial heterogeneity score from a patient’s blood sample. This score allows real‑time screening of an individual’s aging‑phenotype risk and acts as a master reference to shorten development timelines for therapeutics targeting age‑related metabolic diseases.