Tissue homeostasis and aging: new insight from the fly intestine.

Adult somatic stem cells facilitate tissue homeostasis throughout the life of the organism. The mechanisms controlling stem cell activity are under intense scrutiny, with the aims of elucidating how they mediate tissue homeostasis, contribute to age-related decline of adult tissues, and promote tumorigenesis. Recently, the use of model systems such as the Drosophila intestine has enriched our understanding of how stem cells integrate local and systemic signals to maintain tissue and organs function in physiological conditions of homeostasis or after damage. Here we highlight recent advances made in this model allowing a better understanding of stem cell lineage decisions, their regulation by epithelial and intra-organ cues, and their altered activity during aging.