atonal is a proneural gene that directs chordotonal organ formation in the Drosophila peripheral nervous system.
In the Drosophila peripheral nervous system, proneural genes of the achaete-scute complex (ASC) are required for formation of the precursors of external sense organs but not of chordotonal organs. We report the isolation of a gene, atonal (ato), with evidence that it is a proneural gene for the formation of chordotonal organs. This gene is expressed in the proneural clusters and sense organ precursors that give rise to the embryonic and adult chordotonal, but not external sense, organs. Chordotonal organs are eliminated in embryos carrying chromosomal deficiencies that remove ato. Like the ASC products, ato protein contains a basic-helix-loop-helix region and heterodimerizes with daughterless protein to bind to E boxes. Moreover, ectopic expression of ato promotes the formation of extra sense organs. Despite similar proneural properties, we find that ectopic expression of the ASC genes promotes external sense organ formation exclusively, whereas ato promotes chordotonal organ formation preferentially. Thus, proneural genes are major determinants of neuronal identity.
Jarman
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Howard Hughes Medical Institute, University of California, San Francisco 94143.
Grau
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D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D051792:Basic Helix-Loop-Helix Proteins; D002454:Cell Differentiation / Q000235:genetics; D004252:DNA Mutational Analysis; D004268:DNA-Binding Proteins / Q000235:genetics; D004330:Drosophila / Q000196:embryology / Q000235:genetics*; D029721:Drosophila Proteins; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins; D010525:Peripheral Nerves / Q000196:embryology; D012679:Sense Organs / Q000196:embryology*; D017386:Sequence Homology, Amino Acid
D051792:Basic Helix-Loop-Helix Proteins; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D009419:Nerve Tissue Proteins; C082142:ato protein, Drosophila