Muscle structure and innervation are affected by loss of Dorsal in the fruit fly, Drosophila melanogaster.
In Drosophila, the Rel-protein Dorsal and its inhibitor, Cactus, act in signal transduction pathways that control the establishment of dorsoventral polarity during embryogenesis and the immune response during postembryonic life. Here we present data indicating that Dorsal is also involved in the control of development and maintenance of innervation in somatic muscles. Dorsal and Cactus are colocalized in all somatic muscles during postembryonic development. In larvae and adults, these proteins are distributed at low levels in the cytoplasm and nuclei and at much higher levels in the postsynaptic component of glutamatergic neuromuscular junctions. Absence of Dorsal, in homozygous dorsal mutant larvae results in muscle misinsertions, duplications, nuclear hypotrophy, disorganization of actin bundles, and altered subcellular distribution of Cactus. Some muscles show very abnormal neuromuscular junctions, and some motor axon terminals are transformed into growth cone-like structures embedded in synaptotagmin-enriched vesicles. The detailed phenotype suggests a role of Dorsal signalling in the maintenance and plasticity of the NMJ.
Cantera
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R
Zoology Department, Stockholm University, Stockholm, S-10691, Sweden.
Kozlova
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T
Barillas-Mury
C
C
Kafatos
F C
FC
D000818:Animals; D002467:Cell Nucleus / Q000737:chemistry; D003593:Cytoplasm / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics* / Q000254:growth & development; D005260:Female; D018507:Gene Expression Regulation, Developmental; D007091:Image Processing, Computer-Assisted; D019476:Insect Proteins / Q000235:genetics / Q000502:physiology*; D007814:Larva; D008297:Male; D018613:Microscopy, Confocal; D008854:Microscopy, Electron; D009024:Morphogenesis / Q000235:genetics; D024510:Muscle Development; D009124:Muscle Proteins / Q000235:genetics / Q000502:physiology*; D009132:Muscles / Q000002:abnormalities / Q000294:innervation*; D009469:Neuromuscular Junction / Q000254:growth & development* / Q000378:metabolism / Q000648:ultrastructure; D009687:Nuclear Proteins / Q000172:deficiency* / Q000235:genetics / Q000502:physiology; D010641:Phenotype; D010750:Phosphoproteins / Q000172:deficiency* / Q000235:genetics / Q000502:physiology; D017470:Receptors, Glutamate / Q000032:analysis; D014157:Transcription Factors
D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D019476:Insect Proteins; D009124:Muscle Proteins; D009687:Nuclear Proteins; D010750:Phosphoproteins; D017470:Receptors, Glutamate; D014157:Transcription Factors; C062236:dl protein, Drosophila; C077938:cact protein, Drosophila