title: Effects of U0126 and fibroblast growth factor on gene expression profile in Ciona intestinalis embryos as revealed by microarray analysis.
abstract: Fibroblast growth factor (FGF) induces the notochord and mesenchyme in ascidian embryos, via extracellular signal-regulated kinase (ERK) that belongs to the mitogen-activated protein kinase (MAPK) family. A cDNA microarray analysis was carried out to identify genes affected by an inhibitor of MAPK/ERK kinase (MEK), U0126, in embryos of the ascidian Ciona intestinalis. Data obtained from the microarray and in situ hybridization suggest that the majority of genes are downregulated by U0126 treatment. Genes that were downregulated in U0126-treated embryos included Ci-Bra and Ci-Twist-like1 that are master regulatory genes of notochord and mesenchyme differentiation, respectively. The plasminogen mRNA was downregulated by U0126 in presumptive endoderm cells. This suggests that a MEK-mediated extracellular signal is necessary for gene expression in tissues whose specification does not depend on cell-to-cell interaction. Among 85 cDNA clusters that were not affected by U0126, 30 showed mitochondria-like mRNA localization in the nerve cord/muscle lineage blastomeres in the equatorial region. The expression level and asymmetric distribution of these mRNA were independent of MEK signaling.
authors.affiliation: Department of Materials Science, Kochi University, Kochi-shi, Japan.
authors.forename: Eriko
authors.initials: E
authors.lastname: Sakabe
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Tanaka
authors.forename: Naoki
authors.initials: N
authors.lastname: Shimozono
authors.forename: Takashi
authors.initials: T
authors.lastname: Gojobori
authors.forename: Shigeki
authors.initials: S
authors.lastname: Fujiwara
mesh_terms: D000818:Animals; D002070:Butadienes / Q000494:pharmacology*; D002454:Cell Differentiation; D002938:Ciona intestinalis / Q000196:embryology / Q000235:genetics* / Q000254:growth & development; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005346:Fibroblast Growth Factors / Q000494:pharmacology*; D020869:Gene Expression Profiling / Q000379:methods; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects*; D017403:In Situ Hybridization; D020929:Mitogen-Activated Protein Kinase Kinases / Q000037:antagonists & inhibitors; D009570:Nitriles / Q000494:pharmacology*; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D010958:Plasminogen / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051879:Twist-Related Protein 1 / Q000235:genetics; D051176:beta Catenin / Q000235:genetics
chemical_list: D002070:Butadienes; D004791:Enzyme Inhibitors; D009570:Nitriles; D012333:RNA, Messenger; D051879:Twist-Related Protein 1; C113580:U 0126; D051176:beta Catenin; D005346:Fibroblast Growth Factors; D010958:Plasminogen; D020929:Mitogen-Activated Protein Kinase Kinases