part of imaginal disc cuboidal/columnar epithelium disc epithelium proper FBbt:00007029 A columnar epithelial monolayer with marked apical-basal polarity: the apical side faces the disc lumen, the basal side is underlain by a basal lamina. The anterior-posterior compartment boundary of the imaginal discs runs through the middle of this epithelium. Cells in this epithelium are coupled by gap junctions, but this coupling is much reduced across the anterior-posterior compartment boundary. fly_anatomy.ontology