title: Essential roles of fibronectin in the development of the left-right embryonic body plan.
abstract: Studies in Xenopus laevis suggested that cell-extracellular matrix (ECM) interactions regulate the development of the left-right axis of asymmetry; however, the identities of ECM components and their receptors important for this process have remained unknown. We discovered that FN is required for the establishment of the asymmetric gene expression pattern in early mouse embryos by regulating morphogenesis of the node, while cellular fates of the nodal cells, canonical Wnt and Shh signaling within the node were not perturbed by the absence of FN. FN is also required for the expression of Lefty 1/2 and activation of SMADs 2 and 3 at the floor plate, while cell fate specification of the notochord and the floor plate, as well as signaling within and between these two embryonic organizing centers remained intact in FN-null mutants. Furthermore, our experiments indicate that a major cell surface receptor for FN, integrin α5β1, is also required for the development of the left-right asymmetry, and that this requirement is evolutionarily conserved in fish and mice. Taken together, our studies demonstrate the requisite role for a structural ECM protein and its integrin receptor in the development of the left-right axis of asymmetry in vertebrates.
authors.affiliation: Weill Cornell Medical College, Department of Medicine, Division of Cardiology, New York, NY, USA.
authors.forename: Maria V
authors.initials: MV
authors.lastname: Pulina
authors.forename: Shuan-Yu
authors.initials: SY
authors.lastname: Hou
authors.forename: Ashok
authors.initials: A
authors.lastname: Mittal
authors.forename: Dorthe
authors.initials: D
authors.lastname: Julich
authors.forename: Charlie A
authors.initials: CA
authors.lastname: Whittaker
authors.forename: Scott A
authors.initials: SA
authors.lastname: Holley
authors.forename: Richard O
authors.initials: RO
authors.lastname: Hynes
authors.forename: Sophie
authors.initials: S
authors.lastname: Astrof
mesh_terms: D000818:Animals; D019521:Body Patterning; D005109:Extracellular Matrix / Q000378:metabolism*; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D005353:Fibronectins / Q000235:genetics / Q000502:physiology*; D005399:Fishes / Q000196:embryology / Q000254:growth & development; D018507:Gene Expression Regulation, Developmental; D053823:Hedgehog Proteins / Q000378:metabolism; D039081:Integrin alpha5beta1 / Q000378:metabolism*; D055458:Left-Right Determination Factors / Q000378:metabolism; D051379:Mice; D009672:Notochord / Q000196:embryology / Q000254:growth & development; D015398:Signal Transduction; D051899:Smad2 Protein / Q000378:metabolism; D051900:Smad3 Protein / Q000378:metabolism; D051153:Wnt Proteins / Q000378:metabolism
chemical_list: D016326:Extracellular Matrix Proteins; D005353:Fibronectins; D053823:Hedgehog Proteins; D039081:Integrin alpha5beta1; D055458:Left-Right Determination Factors; C111386:Lefty1 protein, mouse; C526162:Lefty2 protein, mouse; C465570:Shh protein, mouse; D051899:Smad2 Protein; C497783:Smad2 protein, mouse; D051900:Smad3 Protein; C497791:Smad3 protein, mouse; D051153:Wnt Proteins