title: Identification of novel retinoic acid target genes.
abstract: Retinoic acid is required for diverse ontogenic processes and as such identification of the genes and pathways affected by retinoic acid is critical to understanding these pleiotropic effects. The presomitic mesoderm of the E8.5 mouse embryo is composed of undifferentiated cells that are depleted of retinoic acid, yet are competent to respond to the retinoid signal. We have exploited these properties to use this tissue to identify novel retinoic acid-responsive genes, including candidate target genes, by treating E8.5 embryos with retinoic acid and assessing changes in gene expression in the presomitic mesoderm by microarray analysis. This exercise yielded a cohort of genes that were differentially expressed in response to exogenous retinoic acid exposure. Among these were a number of previously characterized retinoic acid targets, validating this approach. In addition, we recovered a number of novel candidate target genes which were confirmed as retinoic acid-responsive by independent analysis. Chromatin immunoprecipitation assays revealed retinoic acid receptor occupancy of the promoters of certain of these genes. We further confirmed direct retinoic acid regulation of the F11r gene, a new RA target, using tissue culture models. Our results reveal a significant number of potential RA targets implicated in embryonic development and offer a novel in vivo system for better understanding of retinoid-dependent transcription.
authors.affiliation: Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.
authors.forename: Joanne G A
authors.initials: JG
authors.lastname: Savory
authors.affiliation: Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.
authors.forename: Caitlin
authors.initials: C
authors.lastname: Edey
authors.affiliation: Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada.
authors.forename: Bradley
authors.initials: B
authors.lastname: Hess
authors.affiliation: Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON, Canada.
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Mears
authors.affiliation: Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada. Electronic address: dlohnes@uottawa.ca.
authors.forename: David
authors.initials: D
authors.lastname: Lohnes
mesh_terms: D000818:Animals; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D047369:Chromatin Immunoprecipitation; D017931:DNA Primers / Q000235:genetics; D024202:Electrophoretic Mobility Shift Assay; D004622:Embryo, Mammalian / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects*; D017403:In Situ Hybridization; D008648:Mesoderm / Q000378:metabolism*; D051379:Mice; D046228:Microarray Analysis; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014212:Tretinoin / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D015815:Cell Adhesion Molecules; D017931:DNA Primers; C498686:F11r protein, mouse; D011956:Receptors, Cell Surface; D014212:Tretinoin
keywords: Microarray; Mouse development; Patterning; Retinoic acid receptor; Transcription