overlaps develops from midline glial cell Glial cell that is derived from the mesectoderm (Ito et al., 1995). It is located on or close to the midline of the ventral nerve cord (Ito et al., 1995). At embryonic stage 11, these cells form two populations, an anterior cluster of around 6 cells per neuromere and a posterior cluster of around 4 cells per neuromere (Wheeler et al., 2006). Three of the anterior cells persist into the larval stage, with the rest of the midline glia being lost by apoptosis (Wheeler et al., 2009). In the larva, these cells ensheath the anterior and posterior axon commissures (Ito et al., 1995). midline glia MGM FBbt:00005567 median glial cell FBbt:00001315 fly_anatomy.ontology AMG VFB:FBbt_00001315 ventral midline glia MG Ito et al. (1995) states that there are generally three or four midline glial cells per neuromere, but occasionally there are more than four. The thoracic neuromeres are more likely than the abdominal neuromeres to have more. Midline glia are repo (FBgn0011701) negative and are eliminated by apoptosis during the pupal stage. MGA anterior midline glia glial cell embryonic midline glioblast mesectodermal derivative midline of ventral nerve cord