title: Isolation and characterization of novel mutations of the Broad-Complex, a key regulatory gene of ecdysone induction in Drosophila melanogaster.
abstract: Seven new alleles of the Broad-Complex gene of Drosophila melanogaster, which encodes a family of four zinc finger protein isoforms BR-C Z1, Z2, Z3 and Z4, were generated by transposase-induced mobilization of a P[Zw] element inserted in either the first intron downstream from the P165 promoter or the exon encoding the Z2-specific zinc finger domain. They were characterized by genetic complementation tests, molecular mapping and cytogenetic analysis of their effect on ecdysone-induced puffing and BR-C proteins binding to polytene chromosomes. Four mutations that correspond to three overlapping deletions and one tandem insertion of the P[Zw] element are located in the intron. They provide evidence that regulatory elements essential for a correct expression of the BR-C Z2 and BR-C Z3 transcripts are located within the intron downstream from the P165 promoter. Three mutations correspond to internal deletions of the locus and exhibit a complete loss of all BR-C(+) genetic functions in the complementation and cytogenetic tests. They thus provide well characterized new amorphic reference alleles of the BR-C gene. The precise cytogenetic location of more than 300 binding sites of BR-C proteins on larval salivary gland polytene chromosomes was determined by immunostaining using specific antibodies. Sites were found in big ecdysone inducible puffs, constitutively active small puffs as well as interbands. A complete list of the major sites on all four salivary gland polytene chromosomes of BR-C(+) larvae is presented.
authors.affiliation: Laboratoire de Biologie du Développement, Institut Jacques-Monod, CNRS, Université Paris, 7-Denis Diderot et Université Paris, 6-P et M Curie 75251, Paris Cedex 05, France.
authors.forename: G
authors.initials: G
authors.lastname: Gonzy
authors.forename: G V
authors.initials: GV
authors.lastname: Pokholkova
authors.forename: F
authors.initials: F
authors.lastname: Peronnet
authors.forename: B
authors.initials: B
authors.lastname: Mugat
authors.forename: O V
authors.initials: OV
authors.lastname: Demakova
authors.forename: I V
authors.initials: IV
authors.lastname: Kotlikova
authors.forename: J-A
authors.initials: JA
authors.lastname: Lepesant
authors.forename: I F
authors.initials: IF
authors.lastname: Zhimulev
mesh_terms: D000818:Animals; D002875:Chromosomes; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics; D004440:Ecdysone / Q000096:biosynthesis*; D007814:Larva; D016296:Mutagenesis; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D016335:Zinc Fingers
chemical_list: C102117:Br protein, Drosophila; D029721:Drosophila Proteins; D020033:Protein Isoforms; D014157:Transcription Factors; D004440:Ecdysone