title: Molecular characterization of the lethal of scute genetic function.
abstract: The lethal of scute (l'sc) genetic function, which plays an essential role in the early development of the central nervous system of the Drosophila embryo, is localized within the achaete-scute complex (AS-C). Several lines of evidence have suggested that the AS-C T3 transcription unit corresponds to the l'sc function. We demonstrate that short fragments of DNA, containing the T3 transcribed region and a few kilobases of flanking sequences, rescue, albeit partially, the lethality and neural phenotype of l'sc deletions. Still, the complex wild-type pattern of expression of T3 is not reproduced by the transduced genes. This depends on cis-control elements scattered within the entire AS-C DNA and intermingled with regulatory elements specific for other AS-C transcription units. These elements are necessary for the initial activation of T3 in the neuroectoderm, probably mediated by axis-patterning genes. The presence of a cluster of E-boxes, upstream of the T3 transcribed region, suggests another level of control of T3 expression by basic-helix-loop-helix proteins, among them its own gene product.
authors.affiliation: Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Universidad Autónoma, Madrid, Spain.
authors.forename: M D
authors.initials: MD
authors.lastname: Martín-Bermudo
authors.forename: F
authors.initials: F
authors.lastname: González
authors.forename: M
authors.initials: M
authors.lastname: Domínguez
authors.forename: I
authors.initials: I
authors.lastname: Rodríguez
authors.forename: M
authors.initials: M
authors.lastname: Ruiz-Gómez
authors.forename: S
authors.initials: S
authors.lastname: Romani
authors.forename: J
authors.initials: J
authors.lastname: Modolell
authors.forename: F
authors.initials: F
authors.lastname: Jiménez
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D051792:Basic Helix-Loop-Helix Proteins; D002490:Central Nervous System / Q000196:embryology*; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000235:genetics; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics*; D005786:Gene Expression Regulation; D017344:Genes, Insect; D005804:Genes, Lethal; D005809:Genes, Regulator; D018257:Helix-Loop-Helix Motifs / Q000235:genetics; D008969:Molecular Sequence Data; D009024:Morphogenesis / Q000235:genetics; D010641:Phenotype; D011401:Promoter Regions, Genetic; D017384:Sequence Deletion; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*; D014158:Transcription, Genetic
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D014157:Transcription Factors; C089199:ac protein, Drosophila; C089200:l(1)sc protein, Drosophila; C089197:sc protein, Drosophila