Developmental regulation of progenitor aging shapes long-term intestinal homeostasis in Drosophila.

Aging causes disruption of tissue homeostasis, with stem cell exhaustion as a major hallmark. However, whether aging trajectories are established during development remains unexplored. Here, we demonstrate that genetic modulation of aging-associated pathways in larval adult midgut progenitors (AMPs) determines the trajectory of Drosophila adult intestinal homeostasis. Induction of aging-associated pathways in the AMPs results in aberrant proliferation, skewed differentiation, barrier dysfunction, and genomic instability. Ultimately, AMP islet architecture is destabilized and age-related molecular signatures are altered. In contrast, reversing aging-associated effects results in a decrease in the enteroendocrine population and the barrier is unaffected. Together, our findings demonstrate that aging-associated pathways are tightly regulated during early development and perturbation can hamper adult gut homeostasis, establishing AMPs as key developmental determinants.