title: Molecular characterization of an 18 kb segment of DNA puff C4 of Bradysia hygida (Diptera, sciaridae).
abstract: The data presented here are an extension of the molecular characterization of DNA puff C4 of Bradysia hygida. A cDNA related to a gene amplified in this puff and expressed when puff C4 expands was cloned and sequenced. Analysis of the amino acid sequence deduced from the open reading frame present in the cDNA indicate that the encoded protein is secreted and comprises mostly alpha-helical coiled-coil. An 18 kb genomic segment containing the transcription unit of this gene was also cloned and the structure and expression of the 1.4 kb mRNA was determined. Quantitative slot blot hybridization of DNA complementary to the transcription unit shows that this gene is amplified about 21 times in the salivary gland, confirming data previously obtained. Fragments upstream of the 5' end, and beyond the 3' end, of the gene transcription unit were also analysed and shown to be amplified at least eight and five times, respectively. Based on these data we discuss how amplification could occur at DNA puffs.
authors.affiliation: Departamento de Morfologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP 14049-900, Brazil.
authors.forename: N
authors.initials: N
authors.lastname: Monesi
authors.forename: M A
authors.initials: MA
authors.lastname: Fernandez
authors.forename: A M
authors.initials: AM
authors.lastname: Fontes
authors.forename: L R
authors.initials: LR
authors.lastname: Basso
authors.forename: Y
authors.initials: Y
authors.lastname: Nakanishi
authors.forename: B
authors.initials: B
authors.lastname: Baron
authors.forename: G
authors.initials: G
authors.lastname: Buttin
authors.forename: M L
authors.initials: ML
authors.lastname: Paçó-Larson
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D002875:Chromosomes; D003001:Cloning, Molecular; D018076:DNA, Complementary; D004175:Diptera / Q000235:genetics*; D005260:Female; D005784:Gene Amplification; D017344:Genes, Insect; D019476:Insect Proteins; D008969:Molecular Sequence Data; D011487:Protein Conformation; D012471:Salivary Proteins and Peptides / Q000737:chemistry / Q000235:genetics*
chemical_list: D018076:DNA, Complementary; D019476:Insect Proteins; D012471:Salivary Proteins and Peptides; C095605:puff C4 protein, Bradysia hygida