part of gonad fusome fly_anatomy.ontology Cytoplasmic membrane-rich zones found in developing germline stem cells and their progeny. A small spherical fusome (spectrosome) grows during germline stem cell formation into a large branched structure (polyfusome) that extends through the ring canals into every cyst cell in germarium region 2a. Once the germline cyst has stopped dividing, the fusome begins to break down, usually disappearing soon after the progeny of the germline stem cell leaves the germarium. FBbt:00004862 cell component