A conserved post-maturity imbalance between housekeeping and integrative genome activity in aging.

Abstract

Aging biology still lacks a fully mechanistic explanation for why functional decline accelerates after sexual maturity in the absence of a single initiating pathology. Here, we integrate cross-species epigenetic, transcriptomic, and proteomic datasets to test whether aging is associated with a post-maturity imbalance between two genome partitions: housekeeping genes (HG), which encode the cellular maintenance infrastructure, and integrative genes (IntG), which support specialized tissue functions. We emphasize HG because this compartment defines the basal capacity for repair, proteostasis, biosynthesis, and cell-autonomous survival; changes in HG output may therefore help distinguish candidate upstream regulatory changes from downstream damage signatures. Across datasets, we observe a consistent divergence after sexual maturity: the HG compartment loses transcriptional share in low-renewal tissues, whereas IntG promoter methylation becomes progressively more dispersed, with methylation-mRNA Spearman correlations of rho = -0.15 to -0.28 (five tissues, p < 0.05 FDR) and modest mRNA-protein concordance (rho = 0.204, p < 0.001, n = 6,449), indicating partial post-transcriptional decoupling. These associations are compatible with the continued action of an ontogenetic regulatory program that shifts genome activity toward specialized function at the expense of maintenance. This interpretation is consistent with hyperfunction/developmental theories, while reframing the hyperfunctional state as a possible downstream consequence of asymmetric developmental regulation. Although causality remains to be tested experimentally, the convergence of multi-omics evidence supports a testable model in which restoring HG/IntG regulatory balance may represent a future experimental direction for modulating age-related decline, rather than a translational implication supported by the current data.