title: Zeste tunes the timing of ecdysone actions in triggering programmed tissue degeneration in Drosophila.
abstract: In the pupal stage, the fly body undergoes extensive metamorphic remodeling, in which programmed cell death plays a critical role. We studied two of the constituent processes in this remodeling, salivary gland degeneration and breakdown of the eclosion muscle, which are triggered by an increase and a decrease in the circulating steroid hormone ecdysone at the start and end of metamorphosis, respectively. We found that knockdown of zeste (z), a gene encoding a sequence-specific DNA-binding protein implicated in transvection, in salivary gland cells advances the initiation of their degeneration, whereas z knockdown in neurons delays muscle breakdown. We further showed that knockdown of an ecdysone-inducible gene, E74, retards salivary gland degeneration with little effect on eclosion muscle breakdown. We propose that Z tunes the sensitivity of ecdysone targets to this hormone in order to ensure a high safety margin so that the cell death program will be activated when the ecdysone titer is at a sufficiently high level that is reached only at a defined stage during metamorphosis.
authors.affiliation: a Division of Neurogenetics , Tohoku University Graduate School of Life Sciences , Sendai , Japan and.
authors.forename: Takaaki
authors.initials: T
authors.lastname: Goto
authors.affiliation: a Division of Neurogenetics , Tohoku University Graduate School of Life Sciences , Sendai , Japan and.
authors.forename: Kosei
authors.initials: K
authors.lastname: Sato
authors.affiliation: b Laboratory of Genetics , Waseda University School of Human Sciences, Nishi-Tokyo , Tokyo , Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Sone
authors.affiliation: a Division of Neurogenetics , Tohoku University Graduate School of Life Sciences , Sendai , Japan and.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Koganezawa
authors.affiliation: a Division of Neurogenetics , Tohoku University Graduate School of Life Sciences , Sendai , Japan and.|b Laboratory of Genetics , Waseda University School of Human Sciences, Nishi-Tokyo , Tokyo , Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Ito
authors.affiliation: a Division of Neurogenetics , Tohoku University Graduate School of Life Sciences , Sendai , Japan and.|b Laboratory of Genetics , Waseda University School of Human Sciences, Nishi-Tokyo , Tokyo , Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Yamamoto
mesh_terms: D000367:Age Factors; D000818:Animals; D030801:Animals, Genetically Modified; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004330:Drosophila; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004440:Ecdysone / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D009132:Muscles; D009135:Muscular Diseases / Q000235:genetics; D011679:Pupa; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D012466:Salivary Gland Diseases / Q000235:genetics*; D012469:Salivary Glands / Q000473:pathology*
chemical_list: D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D034741:RNA, Small Interfering; C060849:z protein, Drosophila; D004440:Ecdysone
keywords: Cell death; eclosion muscle; salivary glands; time regulation