Maintenance of Niche Function and Tissue Homeostasis During Aging. Leanne Jones¹, Hila Toledano¹, Cecilia D'Alterio¹, Michael Rera², Christopher Koehler¹, Benjamin Czech³, Erel Levine⁴, David Walker². 1) Laboratory of Genetics, Salk Inst, La Jolla, CA; 2) Department of Integrative Biology and Physiology, University of California- Los Angeles, Los Angeles, CA; 3) Watson School of Biological Sciences, Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY; 4) Department of Physics and FAS Center for Systems Biology, Harvard University, Cambridge, MA.

   Adult stem cells support tissue homeostasis and repair throughout the life of an individual. Numerous changes occur with age that result in altered stem cell behavior and reduced tissue maintenance and regeneration. Changes can be cell autonomous including changes in cell cycle progression, increased DNA damage, and epigenetic alterations. In addition, poorly understood changes to the local and systemic environments occur that result in decreased stem cell activity or alterations in commitment or differentiation potential. We have developed Drosophila melanogaster as a model to uncover conserved mechanisms regulating stem cell aging and explore how cellular and tissue aging impact longevity. We will compare and contrast age-related changes to germline and intestinal stem cells and present strategies to counter age-related changes in both tissues. Understanding the mechanistic basis for intrinsic and extrinsic age-related changes will facilitate stem cell based therapies to treat age-onset and degenerative diseases in older individuals.