Investigating spatial and temporal heterogeneity in mitochondria during aging using in vivo high-content chemical imaging - PROJECT SUMMARY Title: Investigating spatial and temporal heterogeneity in mitochondria during aging using in vivo high- content chemical imaging The spatial and temporal regulation of mitochondria is critical for controlling various cellular processes, including energy balance and metabolism, in specific locations and timeframes. Mitochondria have the ability to dynami- cally adjust their shape, position, activity, and interactions with other cellular components, such as lipid droplets (LDs), to fulfill the diverse functional requirements throughout an animal’s lifespan. However, the precise relation- ship between these spatial and temporal changes in mitochondria and the physiological homeostasis of host cells and mitochondria is not fully understood. To address this question, we have developed advanced in vivo chemi- cal imaging techniques, specifically broadband coherent anti-Stokes Raman scattering (BCARS) and two-photon fluorescence lifetime imaging (2p-FLIM), and a genetically-tractable platform utilizing the nematode Caenorhab- ditis elegans as the model organism. While BCARS and 2p-FLIM provide organelle-resolved data with very high information content associated with the metabolic states of subcellular compartments, the established in vivo platform offers the opportunity to examine various conditions. Our research aims to unravel the heterogeneity of mitochondria in different physiological states, including their interactions with LDs, subcellular localization, and morphology in various tissues and cell types, and under different age and disease conditions within intact living animals. The successful completion of our proposed studies is expected to significantly advance our understand- ing of the intricate relationship between physiological homeostasis and mitochondrial dynamics. Furthermore, the establishment of these novel imaging and analysis approaches will revolutionize the field of mitochondrial biology by providing a groundbreaking tool for reliably examining mitochondrial heterogeneity in vivo.