male accessory gland main cell fly_anatomy.ontology main secretory cell FBbt:00004960 Cell type found in both lobes of the male accessory gland. These cells are flat, hexagonal and binucleate, which secrete their products into the lumen of each lobe. There are approximately 1000 main cells per lobe, interspersed with around 43 secondary cells. semen-secreting cell of the male accessory gland