Senescent cells exhibit features of developmental signaling centres

Cellular senescence is a state that contributes to tissue patterning during development and tissue repair, but which becomes misregulated in ageing and disease. The senescence-associated secretory phenotype (SASP) mediates many of the context-dependent effects, yet its molecular composition and evolutionary origins remain incompletely understood. Here, we characterize the SASP signature of developmental senescent cells and find that it is enriched for genes encoding major developmental signaling pathways. Integrative analyses of in vitro and in vivo transcriptomes reveal that human and mouse senescent cells across diverse contexts consistently activate these developmental programs, with key morphogens constituting conserved SASP components. Functionally, we show that the SASP is sufficient to induce the expression of central developmental genes and transcription factors across multiple cell types. These findings show that senescent cells resemble developmental signaling centers and uncover developmental signaling reactivation as an evolutionarily conserved feature of senescence, providing conceptual insight into its physiological functions and its pathological impact during ageing.