Essential genes for myoblast fusion in Drosophila embryogenesis.
In Drosophila, as in vertebrates, each muscle is a syncytium and arises from mesodermal cells by successive fusion. This requires cell-cell recognition, alignment, formation of prefusion complexes, followed by electron-dense plaques and membrane breakdown. Because muscle development in Drosophila is rapid and well-documented, it has been possible to identify several genes essential for fusion. Molecular analysis of two of these genes revealed the importance of cytoplasmic components. One of these, Myoblast city, is expressed in several tissues and is homologous to the mammalian protein DOCK180. Myoblast city is presumably involved in cell recognition and cell adhesion. Blown fuse, the second cytoplasmic component, is selectively expressed in the mesoderm and essential in order to proceed from the prefusion complex to electron-dense plaques at opposed membranes between adjacent myoblasts. The rolling stone gene is transiently expressed during myoblast fusion. The Rost protein is located in the membrane and thus might be a key component for cell recognition. The molecular characterization of further genes relevant for fusion such as singles bar and sticks and stones will help to elucidate the mechanism of myoblast fusion in Drosophila.
Paululat
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Department of Biology, Philipps-University, Marburg, D-35032, Marburg, Germany.
Holz
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Renkawitz-Pohl
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D000818:Animals; D019521:Body Patterning / Q000235:genetics; D002448:Cell Adhesion; D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins / Q000502:physiology; D004330:Drosophila / Q000196:embryology*; D029721:Drosophila Proteins; D005260:Female; D019204:GTP-Binding Proteins / Q000502:physiology; D019476:Insect Proteins / Q000032:analysis / Q000502:physiology; D007425:Intracellular Membranes / Q000378:metabolism; D064326:MEF2 Transcription Factors; D008297:Male; D008954:Models, Biological; D009124:Muscle Proteins / Q000032:analysis / Q000502:physiology; D009132:Muscles / Q000196:embryology*; D016296:Mutagenesis; D018006:Myogenic Regulatory Factors; D013091:Spermatogenesis; D014157:Transcription Factors / Q000502:physiology; D020744:rac GTP-Binding Proteins
D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D019476:Insect Proteins; D064326:MEF2 Transcription Factors; C499409:Mef2 protein, Drosophila; D009124:Muscle Proteins; D018006:Myogenic Regulatory Factors; C090146:Rac1 protein, Drosophila; D014157:Transcription Factors; C105423:blow protein, Drosophila; C107441:mbc protein, Drosophila; D019204:GTP-Binding Proteins; D020744:rac GTP-Binding Proteins