Our current project (R01 GM139971) is focused on elucidating the mechanisms by which non-centrosomal microtubule-organizing centers (ncMTOCs) function. This is important because many, if not most, non-dividing cells in the organism rely on ncMTOCs rather than the centrosome, the better understood animal MTOC. Considered a new frontier in cytoskeleton research, ncMTOCs are diverse in their structures, subcellular locations, and mechanisms of microtubule assembly. My lab has discovered three distinct ncMTOCs in the past few years, and in this project we focus on discerning the mechanisms by which a perinuclear MTOC in Drosophila adipocytes is assembled and by which it controls microtubule assembly. To achieve the aims of this grant and future projects, confocal microscopy is needed to execute and evaluate experiments and is the most critical core piece of equipment for my research program. The general and ongoing need for intensive confocal microscopy use is reflected in all of our publications in the past 13 years, where we have had ready access to a Nikon A1 confocal microscope housed adjacent to our lab. This instrument is used daily by members of my lab and is now aged, slow and in disrepair. A supplement to fund a new confocal microscope is necessary to assure progress with this project and allow us to retire the current instrument.