title: Differential regulation of the two transcripts from the Drosophila gap segmentation gene hunchback.
abstract: The Drosophila gap gene hunchback (hb) is required for the establishment of the anterior segment pattern of the embryo, and also for a small region of the posterior segment pattern. The hb gene encodes two transcripts from two promoters which show a differential regulation, although they code for the same protein product. The 3.2-kb transcript is expressed during oogenesis and forms an anterior-posterior gradient during the early stages of development. The first zygotic expression of hb during cleavage stages 11-12 is due to the 2.9-kb transcript. Its expression is under the control of the anterior pattern organizer gene bicoid (bcd) and it appears to be necessary and sufficient for the anterior segmentation. The 3.2-kb transcript is expressed again at syncytial blastoderm stage in the anterior yolk nuclei, as well as in an anterior stripe which is posteriorly adjacent to the domain of the 2.9-kb transcript, and as a posterior stripe. Using hb-promoter/lacZ fusion gene constructs in combination with germ line transformation, we have delimited a regulatory region for the 2.9-kb transcript to approximately 300 bp upstream of the site of transcription initiation and show that this region is sufficient to confer the full regulation by bcd.
authors.affiliation: Max-Planck-Institut für Entwicklungsbiologie, Abt. Biochemie, Tübingen, FRG.
authors.forename: C
authors.initials: C
authors.lastname: Schröder
authors.forename: D
authors.initials: D
authors.lastname: Tautz
authors.forename: E
authors.initials: E
authors.lastname: Seifert
authors.forename: H
authors.initials: H
authors.lastname: Jäckle
mesh_terms: D000818:Animals; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics*; D004262:DNA Restriction Enzymes; D004330:Drosophila / Q000235:genetics*; D005786:Gene Expression Regulation; D009693:Nucleic Acid Hybridization; D014158:Transcription, Genetic
chemical_list: D004247:DNA; D004262:DNA Restriction Enzymes