title: Roundabout receptors are critical for foregut separation from the body wall.
abstract: In mammals, precise placement of organs is essential for survival. We show here that inactivation of Roundabout (Robo) receptors 1 and 2 in mice leads to mispositioning of the stomach in the thoracic instead of the abdominal cavity, which likely contributes to poor lung inflation and lethality at birth, reminiscent of congenital diaphragmatic hernia (CDH) cases in humans. Unexpectedly, in Robo mutant mice, the primary defect preceding organ misplacement and diaphragm malformation is a delayed separation of foregut from the dorsal body wall. Foregut separation is a rarely considered morphogenetic event, and our data indicate that it occurs via repulsion of Robo-expressing foregut cells away from the Slit ligand source. In humans, genomic lesions containing Robo genes have been documented in CDH. Our findings suggest that separation of the foregut from the body wall is genetically controlled and that defects in this event may contribute to CDH.
authors: Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI 53706, USA.
authors: Eric Thomas
authors: ET
authors: Domyan
authors: Kelsey
authors: K
authors: Branchfield
authors: Daniel A
authors: DA
authors: Gibson
authors: L A
authors: LA
authors: Naiche
authors: Mark
authors: M
authors: Lewandoski
authors: Marc
authors: M
authors: Tessier-Lavigne
authors: Le
authors: L
authors: Ma
authors: Xin
authors: X
authors: Sun
mesh_terms: D034861:Abdominal Wall / Q000002:abnormalities* / Q000196:embryology / Q000473:pathology; D000818:Animals; D000831:Animals, Newborn; D002448:Cell Adhesion; D002465:Cell Movement; D049109:Cell Proliferation; D003964:Diaphragm / Q000002:abnormalities* / Q000196:embryology / Q000473:pathology; D005260:Female; D005455:Fluorescent Antibody Technique; D041981:Gastrointestinal Tract / Q000002:abnormalities* / Q000196:embryology / Q000473:pathology; D005804:Genes, Lethal; D006023:Glycoproteins / Q000502:physiology*; D007124:Immunoenzyme Techniques; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D009419:Nerve Tissue Proteins / Q000502:physiology*; D011971:Receptors, Immunologic / Q000502:physiology*; D000097905:Roundabout Proteins
chemical_list: D006023:Glycoproteins; D009419:Nerve Tissue Proteins; D011971:Receptors, Immunologic; D000097905:Roundabout Proteins; C498888:Robo2 protein, mouse; C120566:slit protein, vertebrate