title: Synaptic patterning by morphogen signaling.
abstract: Gradients of secreted small morphogenic molecules control cell proliferation and patterning throughout animal development. Recent years have seen the discovery of surprising roles for morphogens in later developmental processes, including axon pathfinding and synaptogenesis. The latest addition is a role for the TGF-beta superfamily morphogen Activin in synaptic patterning of the Drosophila visual system. In contrast to classical instructive and long-range morphogen gradients, Activin acts as a permissive and local motility restriction signal around several hundred individual photoreceptor axon terminals. Activin must therefore act in concert with other instructively attracting and repelling signals as part of a larger genetic program for brain wiring.
authors.affiliation: Department of Physiology and Green Center Division for Systems Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: W Ryan
authors.initials: WR
authors.lastname: Williamson
authors.forename: P Robin
authors.initials: PR
authors.lastname: Hiesinger
mesh_terms: D028341:Activins / Q000378:metabolism; D000818:Animals; D001692:Biological Transport; D019521:Body Patterning; D001921:Brain / Q000378:metabolism; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster; D000072159:Dynactin Complex; D006728:Hormones / Q000378:metabolism / Q000502:physiology*; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D008954:Models, Biological; D009154:Mutation; D010215:Papio; D015398:Signal Transduction; D013569:Synapses / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; D000072159:Dynactin Complex; D006728:Hormones; D008869:Microtubule-Associated Proteins; D028341:Activins