Glia relay differentiation cues to coordinate neuronal development in Drosophila

• Published in: Science (American Association for the Advancement of Science) Vol. 357; no. 6354; pp. 886 - 891
• Main Authors: Fernandes, Vilaiwan M., Chen, Zhenqing, Rossi, Anthony M., Zipfel, Jaqueline, Desplan, Claude
• Format: Journal Article
• Language: English
• Published: United States American Association for the Advancement of Science 01.09.2017; The American Association for the Advancement of Science
• Subjects: Alternation learning; Animals; Axons; Brain; Brain architecture; Cues; Differentiation; Drosophila; Drosophila melanogaster - cytology; Drosophila melanogaster - embryology; Drosophila melanogaster - genetics; Drosophila Proteins - genetics; Drosophila Proteins - metabolism; Epidermal growth factor; ErbB Receptors - genetics; ErbB Receptors - metabolism; Glial cells; Individualized Instruction; Insects; Insulin; Insulin - metabolism; Membrane Proteins - genetics; Membrane Proteins - metabolism; Mutation; Neural networks; Neurogenesis; Neuroglia - cytology; Neuronal-glial interactions; Neurons; Optic lobe; Optic Lobe, Nonmammalian - cytology; Optic Lobe, Nonmammalian - embryology; Patterning; Peptides; Photoreception; Photoreceptor Cells, Invertebrate - cytology; Photoreceptors; Receptors, Invertebrate Peptide - genetics; Receptors, Invertebrate Peptide - metabolism; Relay; Sensory systems; Serine Endopeptidases - genetics; Serine Endopeptidases - metabolism; Signal Transduction; Signaling; Topographic mapping; Topographic maps; Topography; Visual pathways; Visual system
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.aan3174

Neuronal birth and specification must be coordinated across the developing brain to generate the neurons that constitute neural circuits. We used the Drosophila visual system to investigate how development is coordinated to establish retinotopy, a feature of all visual systems. Photoreceptors achieve retinotopy by inducing their target field in the optic lobe, the lamina neurons, with a secreted differentiation cue, epidermal growth factor (EGF). We find that communication between photoreceptors and lamina cells requires a signaling relay through glia. In response to photoreceptor-EGF, glia produce insulin-like peptides, which induce lamina neuronal differentiation. Our study identifies a role for glia in coordinating neuronal development across distinct brain regions, thus reconciling the timing of column assembly with that of delayed differentiation, as well as the spatiotemporal pattern of lamina neuron differentiation.