Abstract
Migration and proliferation have been mostly explored in culture systems or fixed preparations. We present a simple genetic model, the chains of glia moving along fly wing nerves, to follow such dynamic processes by time-lapse in the whole animal. We show that glia undergo extensive cytoskeleton and mitotic apparatus rearrangements during division and migration. Single cell labelling identifies different glia: pioneers with high filopodial, exploratory, activity and, less active followers. In combination with time-lapse, altering this cellular environment by genetic means or cell ablation has allowed to us define the role of specific cell-cell interactions. First, neurone-glia interactions are not necessary for glia motility but do affect the direction of migration. Second, repulsive interactions between glia control the extent of movement. Finally, autonomous cues control proliferation.
