Novel gcm-dependent lineages in the postembryonic nervous system of Drosophila melanogaster

glial cells missing genes (gem and gcm2) act as the glial fate determinants in the Drosophila embryo. However, their requirement in the adult central nervous system (CNS) is at present not known, except for their role in lamina glia. This is particularly important with respect to two recent sets of data. Adult glial subpopulations differentiate through embryonic glia proliferation. Also, gem-gem2 are required for the differentiation of specific adult neurons. We here show that gem is expressed in precursors and postmitotic, migrating, cells of the medulla neuropile glia (mng) lineage. It is also expressed in a thoracic glial lineage and in neurons of the ventral nerve cord (VNC). Finally, while gem is required for gliogenesis in medulla and VNC, it does not seem to be required for the generation of VNC neurons.