title: Mutant molecular motors disrupt neural circuits in Drosophila.
abstract: A dominant negative mutation, Glued1, that codes for a component of the dynactin complex, disrupted the axonal anatomy of leg sensory neurons in Drosophila. To examine neuron structure in mutant animals, a P[Gal4] enhancer trap targeted expression of lacZ to the sensory neurons and thereby labeled neurons in the femoral chordotonal organ and their axons within the central nervous system. When these sensory axons were examined in the Glued1 mutant specimens, they were observed to arborize abnormally. This anatomical disruption of the sensory axons was associated with a corresponding disruption in a reflex. Normally, the tibial extensor motor neurons were excited when the femoral-tibial joint was flexed, but this resistance reflex was nearly absent in mutant animals. We used the P[Gal4] insertion strains to target expression of tetanus toxin light chain to these sensory neurons in wild-type animals and showed that this blocked the resistance reflex and produced a phenocopy of the Glued result. We conclude that disruption of the dynein-dynactin complex disrupts sensory axon path finding during metamorphosis, and this in turn disrupts synaptic connectivity.
authors.affiliation: Department of Biology, Morrill Science Center, University of Massachusetts, Amherst 01003, USA.
authors.forename: S
authors.initials: S
authors.lastname: Reddy
authors.forename: P
authors.initials: P
authors.lastname: Jin
authors.forename: J
authors.initials: J
authors.lastname: Trimarchi
authors.forename: P
authors.initials: P
authors.lastname: Caruccio
authors.forename: R
authors.initials: R
authors.lastname: Phillis
authors.forename: R K
authors.initials: RK
authors.lastname: Murphey
mesh_terms: D000818:Animals; D001369:Axons / Q000502:physiology; D003433:Crosses, Genetic; D004330:Drosophila; D000072159:Dynactin Complex; D004576:Electromyography; D006579:Heterozygote; D017403:In Situ Hybridization; D008869:Microtubule-Associated Proteins / Q000235:genetics*; D009046:Motor Neurons / Q000502:physiology*; D009154:Mutation; D009434:Neural Pathways / Q000502:physiology*; D009475:Neurons, Afferent / Q000502:physiology*; D013569:Synapses / Q000502:physiology; D013744:Tetanus Toxin / Q000494:pharmacology; D013900:Thoracic Nerves / Q000502:physiology; D013979:Tibial Nerve / Q000502:physiology
chemical_list: D000072159:Dynactin Complex; D008869:Microtubule-Associated Proteins; D013744:Tetanus Toxin