part of dorsal median cell FBbt:00001326 TN exit glial cell fly_anatomy.ontology VFB:FBbt_00001326 Muscle cell of mesodermal origin that is located on the dorsal surface of the midline of the ventral nerve cord, associated with the embryonic transverse nerve. It is found from T1 to A7 segments. At stage 11 its cell body is round, whereas at stage 14 it displays a characteristic triangle shape, with processes that extend anteriorly and laterally from the vertices, across the width of the ventral nerve cord, to terminate on lateral body muscles. It displays both neural and glial characteristics. These processes act as pioneer for the neurons that fasciculate with the transverse nerve. At stage 11 there are 4 cells, but by stage 14, when these cells have matured, there are only 2. DM transverse nerve exit glial cell larval peripheral nervous system trunk mesoderm derivative embryonic/larval midline accessory cell