title: 20-OH-ecdysone regulates 60 C beta tubulin gene expression in Kc cells and during Drosophila development.
abstract: Cultured Kc cells of Drosophila melanogaster are sensitive to the insect moulting hormone, 20-hydroxy-ecdysone (20-OH-E). Morphological changes of Kc-treated cells were observed and electron microscopic analysis of pseudopodia shows a large increase in the number of microtubules, all arranged in the same orientation. The 60 C beta tubulin gene which is expressed only in 20-OH-E-treated cells encodes a 2.6-kb mRNA which is essentially cytoplasmic and polyadenylated. The corresponding premessenger is 7 kb in length and is absent in untreated cells. Two peaks of expression of the 60 C beta tubulin gene are observed during Drosophila development: at midembryogenesis (stage 8-13 h) and at the late third instar larvae-early pupae stage. By use of the Ecdysone 1 mutant, 60 C beta tubulin gene expression was demonstrated to be regulated in part by 20-OH-E during Drosophila development. Through these two complementary biological models of study, the mode and role of beta tubulin gene regulation are discussed.
authors.affiliation: Laboratoire de Biochimie Médicale, UFR de Médecine, Clermont-Ferrand, France.
authors.forename: M L
authors.initials: ML
authors.lastname: Sobrier
authors.forename: S
authors.initials: S
authors.lastname: Chapel
authors.forename: J L
authors.initials: JL
authors.lastname: Couderc
authors.forename: D
authors.initials: D
authors.lastname: Micard
authors.forename: P
authors.initials: P
authors.lastname: Lecher
authors.forename: G
authors.initials: G
authors.lastname: Somme-Martin
authors.forename: B
authors.initials: B
authors.lastname: Dastugue
mesh_terms: D000818:Animals; D015152:Blotting, Northern; D002451:Cell Compartmentation; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D004331:Drosophila melanogaster / Q000235:genetics* / Q000254:growth & development; D004441:Ecdysterone / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects*; D008870:Microtubules / Q000648:ultrastructure; D005810:Multigene Family; D009154:Mutation; D012333:RNA, Messenger / Q000235:genetics; D014158:Transcription, Genetic; D014404:Tubulin / Q000235:genetics*
chemical_list: D012333:RNA, Messenger; D014404:Tubulin; D004441:Ecdysterone