title: Stage-specific expression of the chitin synthase DmeChSA and DmeChSB genes during the onset of Drosophila metamorphosis.
abstract: Chitin, the major structural polysaccharide of arthropods, is an important constituent of the insect extracellular structures, cuticle and gut peritrophic matrix. Synthesis of cuticular chitin is strictly coordinated with the ecdysone-regulated molting cycle of insect development (the term "ecdysone" is used in this paper instead of "ecdysteroids" since the exact ratio of various hormonal forms changes during metamorphosis). Based on observed similarities between the fungal chitin synthases and other processive beta-glycosyltransferases, we have identified the first insect chitin synthase genes, DmeChSA and DmeChSB (Database accession numbers: EMBL/GenBank/DDBJ A83122, A83126, AJ309488, AJ309489), from Drosophila melanogaster. Chromosomal localization has identified these genes close to and on either side of the centromere of the third chromosome. Partial cDNA clones of both genes have been isolated from a pupal cDNA library. To obtain the first insight into the transcriptional regulation of chitin synthesis, we have monitored the expression of DmeChSA and DmeChSB during the periods of the late-larval and prepupal ecdysone pulses that direct metamorphosis. Transcripts of either gene are barely detected prior to and during the late-larval ecdysone pulse. Once the late-larval ecdysone pulse is ceased completely, both DmeChSA and DmeChSB genes show a remarkable up-regulation.
authors.affiliation: Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology - Hellas, 711 10 Heraklion, Crete, Greece.
authors.forename: Mary Elizabeth
authors.initials: ME
authors.lastname: Gagou
authors.forename: Manuela
authors.initials: M
authors.lastname: Kapsetaki
authors.forename: Andreas
authors.initials: A
authors.lastname: Turberg
authors.forename: Dimitris
authors.initials: D
authors.lastname: Kafetzopoulos
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D015139:Blotting, Southern; D002687:Chitin Synthase / Q000235:genetics*; D018076:DNA, Complementary; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D015870:Gene Expression; D017403:In Situ Hybridization; D008675:Metamorphosis, Biological / Q000502:physiology*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012469:Salivary Glands; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: C102117:Br protein, Drosophila; D018076:DNA, Complementary; D029721:Drosophila Proteins; D014157:Transcription Factors; C449033:Chs2 protein, Drosophila; C449034:kkv protein, Drosophila; D002687:Chitin Synthase