title: Fascin controls neuronal class-specific dendrite arbor morphology.
abstract: The branched morphology of dendrites represents a functional hallmark of distinct neuronal types. Nonetheless, how diverse neuronal class-specific dendrite branches are generated is not understood. We investigated specific classes of sensory neurons of Drosophila larvae to address the fundamental mechanisms underlying the formation of distinct branch types. We addressed the function of fascin, a conserved actin-bundling protein involved in filopodium formation, in class III and class IV sensory neurons. We found that the terminal branchlets of different classes of neurons have distinctive dynamics and are formed on the basis of molecularly separable mechanisms; in particular, class III neurons require fascin for terminal branching whereas class IV neurons do not. In class III neurons, fascin controls the formation and dynamics of terminal branchlets. Previous studies have shown that transcription factor combinations define dendrite patterns; we find that fascin represents a downstream component of such programs, as it is a major effector of the transcription factor Cut in defining class III-specific dendrite morphology. Furthermore, fascin defines the morphological distinction between class III and class IV neurons. In fact, loss of fascin function leads to a partial conversion of class III neurons to class IV characteristics, while the reverse effect is obtained by fascin overexpression in class IV neurons. We propose that dedicated molecular mechanisms underlie the formation and dynamics of distinct dendrite branch types to elicit the accurate establishment of neuronal circuits.
authors: Dendrite Differentiation Group, Department of Molecular Neurobiology, MPI of Neurobiology, 82152 Munich-Martinsried, Germany.
authors: Julia
authors: J
authors: Nagel
authors: Caroline
authors: C
authors: Delandre
authors: Yun
authors: Y
authors: Zhang
authors: Friedrich
authors: F
authors: Förstner
authors: Adrian W
authors: AW
authors: Moore
authors: Gaia
authors: G
authors: Tavosanis
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003712:Dendrites / Q000378:metabolism / Q000648:ultrastructure; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D017344:Genes, Insect; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D007814:Larva / Q000254:growth & development / Q000378:metabolism; D008840:Microfilament Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009415:Nerve Net / Q000254:growth & development / Q000378:metabolism; D055495:Neurogenesis / Q000235:genetics / Q000502:physiology; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D011984:Sensory Receptor Cells / Q000145:classification / Q000378:metabolism* / Q000648:ultrastructure; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D008840:Microfilament Proteins; D009687:Nuclear Proteins; D014157:Transcription Factors; C066381:ct protein, Drosophila; C020324:fascin