title: Tissue-specific gene expression and ecdysone-regulated genomic networks in Drosophila.
abstract: During insect metamorphosis, each tissue displays a unique physiological and morphological response to the steroid hormone 20-hydroxyecdysone (ecdysone). We assayed gene expression in five tissues during metamorphosis onset. Larval-specific tissues display major changes in genome-wide expression profiles, whereas tissues that survive into adulthood display few changes. In one larval tissue, the salivary gland, we used a computational approach to identify a regulatory motif and a cognate transcription factor involved in regulating a set of coexpressed genes. During the metamorphosis of another tissue, the midgut, genes encoding factors from the hedgehog, Notch, EGF, dpp, and wingless pathways are activated by the ecdysone regulatory network. Mutation of the ecdysone receptor abolishes their induction. Cell cycle genes are also activated during the initiation of midgut metamorphosis, and they are also dependent on ecdysone signaling. These results establish multiple new connections between the ecdysone regulatory network and other well-studied regulatory networks.
authors.affiliation: Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA.
authors.forename: Tong-Ruei
authors.initials: TR
authors.lastname: Li
authors.forename: Kevin P
authors.initials: KP
authors.lastname: White
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D016384:Consensus Sequence; D004330:Drosophila / Q000196:embryology / Q000235:genetics*; D004440:Ecdysone / Q000235:genetics / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D017344:Genes, Insect; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000196:embryology; D008675:Metamorphosis, Biological; D008969:Molecular Sequence Data; D009154:Mutation; D034741:RNA, Small Interfering / Q000378:metabolism; D011987:Receptors, Steroid / Q000235:genetics; D012469:Salivary Glands / Q000196:embryology / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D019076:Transgenes
chemical_list: D034741:RNA, Small Interfering; D011987:Receptors, Steroid; D014157:Transcription Factors; D004440:Ecdysone