Glial Cells in Neural Development

AbstractGlial cells and neurons depend on each other from birth to death. Glial cells accomplish many tasks for the proper development of the nervous system and for the maintenance of neurological functions. This review focuses on recent findings in the simpleDrosophilamodel and underlines the similarities and differences between fly and vertebrate glia. The molecular and cellular mechanisms underlying gliogenesis will be reviewed as well as the role of the master regulatory gene of the glial fate:glial cells deficient/glial cells missing (glide/gcm).All along the review, the features shared between glia and macrophages are highlighted, asglide/gcmis also required in macrophage development and fly glia behave as nervous system‐specific scavenger cells. Finally, the recent data about the developmental pathways and the role of fly glia prompt us to reconsider the origin of glial cells during evolution.Key Concepts:Glial cells are very diversified in terms of morphology, function and gene expression profile.Glial cells are absolutely required for nervous system development and to support neuronal functions.Vertebrate and invertebrate nervous systems share many similarities.Glial cells are the immune cells of theDrosophilanervous system.Glial cells are very dynamic and migrate collectively over long distances.Most glia and neurons arise from common precursors.glide/gcmtranscription factor represents the master gene of the glial fate inDrosophilaacting as a genetic switch between neuron and glia.glide/gcmis expressed and required inDrosophilaglia and macrophages.Glia and macrophages share molecular and cellular pathways.Thegcmortholog genes are not necessary in vertebrate glial development.