Apterous mediates development of direct flight muscles autonomously and indirect flight muscles through epidermal cues.
Two physiologically distinct types of muscles, the direct and indirect flight muscles, develop from myoblasts associated with the Drosophila wing disc. We show that the direct flight muscles are specified by the expression of Apterous, a Lim homeodomain protein, in groups of myoblasts. This suggests a mechanism of cell-fate specification by labelling groups of fusion competent myoblasts, in contrast to mechanisms in the embryo, where muscle cell fate is specified by single founder myoblasts. In addition, Apterous is expressed in the developing adult epidermal muscle attachment sites. Here, it functions to regulate the expression of stripe, a gene that is an important element of early patterning of muscle fibres, from the epidermis. Our results, which may have broad implications, suggest novel mechanisms of muscle patterning in the adult, in contrast to embryonic myogenesis.
Ghazi
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National Centre for Biological Sciences, TIFR, Bangalore 560065, India.
Anant
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VijayRaghavan
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D000818:Animals; D030801:Animals, Genetically Modified; D004268:DNA-Binding Proteins / Q000235:genetics; D004330:Drosophila / Q000235:genetics / Q000254:growth & development* / Q000502:physiology; D029721:Drosophila Proteins; D005426:Flight, Animal / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D017344:Genes, Insect; D018398:Homeodomain Proteins; D060850:LIM-Homeodomain Proteins; D007763:Lac Operon; D024510:Muscle Development; D018482:Muscle, Skeletal / Q000254:growth & development*; D009154:Mutation; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*; D014921:Wings, Animal / Q000254:growth & development
D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D060850:LIM-Homeodomain Proteins; D014157:Transcription Factors; C074459:ap protein, Drosophila; C096359:sr protein, Drosophila