part of copper cell adult midgut region R3ab enterocyte of middle adult midgut epithelium adult copper cell 2014-06-05T17:29:32Z adult cuprophilic cell Specialized cell of the adult midgut found in the anterior and middle midgut sections of region R3 (R3a and R3b, copper cell region). It secretes acid and accumulates copper. They show a distinct apical invagination, basally located nuclei, numerous mitochondria and a deeply invaginated apical membrane covered with long microvilli. Interstitial cells arch over the apex of the copper cell, forming a narrow channel that connects the apical invagination of the copper cell to the gut lumen. The highly folded area of apicolateral contact between copper and interstitial cells contains smooth septate junctions. fly_anatomy.ontology FBbt:00110908