title: Expression and regulation of Groucho-related genes in the embryonic chicken feather bud.
abstract: The groucho-related gene (Grg) products modulate the transcriptional response to several extracellular signals, including the Wnts. In an effort to define the roles of Grgs in the morphogenesis of the feather bud, cDNAs encoding members of the Grg family were cloned from embryonic chick skin. In situ hybridization was used to localize transcripts for cGrg2, Grg3, Grg4, and Grg5 in embryos from day 6 through day 9. Expression of cGrg2, 3, and 5 is detected throughout the initial epidermal placode. As the buds mature, expression becomes limited to the posterior halves and eventually to the distal tip of the outgrowing bud. This pattern and the effects of forced activation of the bone morphogenetic protein and beta-catenin signal transduction pathways on Grg gene expression suggest that these genes act downstream of the early activation of the beta-catenin pathway that initiates placode formation. Induction of Grg genes by beta-catenin may serve as a negative feedback to modulate pathway activation while also altering the activity of other transduction pathways involved in bud patterning.
authors.affiliation: Cutaneous Biology Research Center, Massachusetts General Hospital, Charlestown, Massachusetts 02129, USA.
authors.forename: Leslie
authors.initials: L
authors.lastname: Houghton
authors.forename: Allison
authors.initials: A
authors.lastname: Freeman
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Morgan
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019485:Bone Morphogenetic Proteins / Q000378:metabolism; D002642:Chick Embryo; D002645:Chickens; D003598:Cytoskeletal Proteins / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics; D005241:Feathers / Q000196:embryology* / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D008969:Molecular Sequence Data; D011506:Proteins / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics*; D015398:Signal Transduction / Q000502:physiology; D015534:Trans-Activators / Q000378:metabolism; D051176:beta Catenin
chemical_list: D019485:Bone Morphogenetic Proteins; D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins; D011506:Proteins; D012097:Repressor Proteins; C434947:Tle2 protein, mouse; D015534:Trans-Activators; D051176:beta Catenin