DNA methylation clocks show slower progression of aging in naked mole-rat queens
Naked mole-rats (NMRs) live an exceptionally long life, appear not to exhibit age-related decline in physiological capacity, and are seemingly resistant to age-related diseases. However, it has been unknown whether NMRs also evade aging according to a primary hallmark of aging: epigenetic changes. To address this question, we generated DNA methylation profiles from 329 tissues from animals of known age, at loci that are highly conserved between mammalian species, using a custom Infinium array (HorvathMammalMethylChip40). We observed strong aging effects on NMR DNA methylation, from which we developed seven highly accurate age estimators (epigenetic clocks) for several tissues (pan-tissue, blood, kidney clock, liver clock, skin clock) and two dual species (human-NMR) clocks. By identifying age-related cytosine methylation that are shared between NMR and humans, but not with the mouse, we identified genes and cellular pathways that impinge on developmental and metabolic processes that are potentially involved in NMR and human longevity. The NMR epigenetic clocks revealed that breeding NMR queens age more slowly than non-breeders, a feature that is also observed in some eusocial insects. CpGs associated with queen status were located near developmental genes and those that are regulated by the LHX3 transcription factor that controls pituitary development. In summary, our study demonstrates that despite a phenotype of reduced senescence, the NMR ages epigenetically through developmental and metabolic processes, and that NMR queens age more slowly than non-breeders.