title: Mouse limb deformity mutations disrupt a global control region within the large regulatory landscape required for Gremlin expression.
abstract: The mouse limb deformity (ld) mutations cause limb malformations by disrupting epithelial-mesenchymal signaling between the polarizing region and the apical ectodermal ridge. Formin was proposed as the relevant gene because three of the five ld alleles disrupt its C-terminal domain. In contrast, our studies establish that the two other ld alleles directly disrupt the neighboring Gremlin gene, corroborating the requirement of this BMP antagonist for limb morphogenesis. Further doubts concerning an involvement of Formin in the ld limb phenotype are cast, as a targeted mutation removing the C-terminal Formin domain by frame shift does not affect embryogenesis. In contrast, the deletion of the corresponding genomic region reproduces the ld limb phenotype and is allelic to mutations in Gremlin. We resolve these conflicting results by identifying a cis-regulatory region within the deletion that is required for Gremlin activation in the limb bud mesenchyme. This distant cis-regulatory region within Formin is also altered by three of the ld mutations. Therefore, the ld limb bud patterning defects are not caused by disruption of Formin, but by alteration of a global control region (GCR) required for Gremlin transcription. Our studies reveal the large genomic landscape harboring this GCR, which is required for tissue-specific coexpression of two structurally and functionally unrelated genes.
authors.affiliation: Developmental Genetics, Department of Clinical-Biological Sciences, University of Basel Medical School, CH-4056 Basel, Switzerland.
authors.forename: Aimée
authors.initials: A
authors.lastname: Zuniga
authors.forename: Odyssé
authors.initials: O
authors.lastname: Michos
authors.forename: François
authors.initials: F
authors.lastname: Spitz
authors.forename: Anna-Pavlina G
authors.initials: AP
authors.lastname: Haramis
authors.forename: Lia
authors.initials: L
authors.lastname: Panman
authors.forename: Antonella
authors.initials: A
authors.lastname: Galli
authors.forename: Kristina
authors.initials: K
authors.lastname: Vintersten
authors.forename: Christian
authors.initials: C
authors.lastname: Klasen
authors.forename: William
authors.initials: W
authors.lastname: Mansfield
authors.forename: Sylwia
authors.initials: S
authors.lastname: Kuc
authors.forename: Denis
authors.initials: D
authors.lastname: Duboule
authors.forename: Rosanna
authors.initials: R
authors.lastname: Dono
authors.forename: Rolf
authors.initials: R
authors.lastname: Zeller
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D016207:Cytokines; D005326:Fetal Proteins / Q000235:genetics; D000080865:Formins; D018507:Gene Expression Regulation, Developmental; D053823:Hedgehog Proteins; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics*; D018878:Limb Buds / Q000502:physiology; D017880:Limb Deformities, Congenital / Q000235:genetics*; D008648:Mesoderm; D051379:Mice; D008840:Microfilament Proteins; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics; D017434:Protein Structure, Tertiary; D012326:RNA Splicing; D012045:Regulatory Sequences, Nucleic Acid; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism
chemical_list: D016207:Cytokines; D005326:Fetal Proteins; D000080865:Formins; D053823:Hedgehog Proteins; D036341:Intercellular Signaling Peptides and Proteins; D008840:Microfilament Proteins; D009687:Nuclear Proteins; D015534:Trans-Activators; C113178:Grem1 protein, mouse; C465570:Shh protein, mouse