Glial cells form part of the neural stem cell niche and express a wide variety of ion channels; however, the contribution of these channels to nervous system development is poorly understood. We explored the function of the Drosophila ClC-a chloride channel, since its mammalian ortholog CLCN2 is expressed in glial cells, and defective channel function results in leukodystrophies, which in humans are accompanied by cognitive impairment. We found that ClC-a was expressed in the niche in cortex glia, which are closely associated with neurogenic tissues. Characterization of loss-of-function ClC-a mutants revealed that these animals had smaller brains and widespread wiring defects. We showed that ClC-a is required in cortex glia for neuroepithelia and neuroblast proliferation and identified defects in a neuroblast lineage that generates guidepost glial cells essential for photoreceptor axon guidance. We propose that glia-mediated ionic homeostasis could non-autonomously affect neurogenesis, and consequently, the correct assembly of neural circuits.

Drosophila ClC-a is required in glia of the stem cell niche for proper neurogenic proliferation and wiring of neural circuits