title: A glutamate receptor-interacting protein homolog organizes muscle guidance in Drosophila.
abstract: During Drosophila embryogenesis, developing muscles extend growth-cone-like structures to navigate toward specific epidermal attachment sites. Here, we show that the homolog of Glutamate Receptor-Interacting Proteins (DGrip) acts as a key component of proper muscle guidance. Mutations in dgrip impair patterning of ventral longitudinal muscles (VLMs), whereas lateral transverse muscles (LTMs) that attach to intrasegmental attachment sites develop normally. Myoblast fusion, stabilization of muscle contacts, and general muscle function are not impaired in the absence of DGrip. Instead, the proper formation of cellular extensions during guidance fails in dgrip mutant VLMs. DGrip protein concentrates at the ends of VLMs while these muscles guide toward segment border attachment sites. Conversely, LTMs overexpressing DGrip form ectopic cellular extensions that can cause attachment of these muscles to other muscles at segment borders. Our data suggest that DGrip participates in the reception of an attractive signal that emanates from the epidermal attachment sites to direct the motility of developing muscles. This dgrip phenotype should be valuable to study mechanistic principles of Grip function.
authors.affiliation: European Neuroscience Institute Göttingen, Max-Planck-Society, 37073 Göttingen, Germany.
authors.forename: Laura E
authors.initials: LE
authors.lastname: Swan
authors.forename: Carolin
authors.initials: C
authors.lastname: Wichmann
authors.forename: Ulrike
authors.initials: U
authors.lastname: Prange
authors.forename: Andreas
authors.initials: A
authors.lastname: Schmid
authors.forename: Manuela
authors.initials: M
authors.lastname: Schmidt
authors.forename: Tobias
authors.initials: T
authors.lastname: Schwarz
authors.forename: Evgeni
authors.initials: E
authors.lastname: Ponimaskin
authors.forename: Frank
authors.initials: F
authors.lastname: Madeo
authors.forename: Gerd
authors.initials: G
authors.lastname: Vorbrüggen
authors.forename: Stephan J
authors.initials: SJ
authors.lastname: Sigrist
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D002454:Cell Differentiation / Q000502:physiology; D004330:Drosophila / Q000196:embryology* / Q000378:metabolism; D029721:Drosophila Proteins; D008565:Membrane Proteins; D009132:Muscles / Q000002:abnormalities / Q000196:embryology* / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D018091:Receptors, AMPA / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D029721:Drosophila Proteins; C491307:Grip protein, Drosophila; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D018091:Receptors, AMPA