Hidalgo Magdalena, Sirour Cathy, Bello Valérie, Moreau Nicole, Beaudry Michèle, Darribère Thierry
Université Pierre et Marie Curie Paris 6 UMR CNRS 7622, Laboratoire de Biologie du Développement, équipe Matrice Extracellulaire et Développement, Paris, France.
Dev Dyn. 2009 Jun;238(6):1332-45. doi: 10.1002/dvdy.21814.
Dystroglycan (Dg) is a cell adhesion receptor for laminin that has been reported to play a role in skeletal muscle cell stability, cytoskeletal organization, cell polarity, and signaling. Here we show that Dg is expressed at both the notochord/somite and the intersomitic boundaries, where laminin and fibronectin are accumulated during somitogenesis. Inhibition of Dg function with morpholino antisense oligonucleotides or a dominant negative mutant results in the normal segmentation of the presomitic mesoderm but affects the number, the size, and the integrity of somites. Depletion of Dg disrupts proliferation and alignment of myoblasts without affecting XMyoD and XMRF4 expression. It also leads to defects in laminin deposition at the intersomitic junctions, whereas expression of integrin beta1 subunits and fibronectin assembly occur normally. Our results show that Dg is critical for both proliferation and elongation of somitic cells and that the Dg-cytoplasmic domain is required for the laminin assembly at the intersomitic boundaries. Developmental Dynamics 238:1332-1345, 2009. (c) 2008 Wiley-Liss, Inc.
肌营养不良聚糖（Dg）是层粘连蛋白的一种细胞粘附受体，据报道它在骨骼肌细胞稳定性、细胞骨架组织、细胞极性和信号传导中发挥作用。在这里我们表明，Dg在脊索/体节以及体节间边界处均有表达，在体节形成过程中层粘连蛋白和纤连蛋白会在这些部位积累。用吗啉代反义寡核苷酸或显性负性突变体抑制Dg功能会导致前体中胚层正常分节，但会影响体节的数量、大小和完整性。Dg的缺失会破坏成肌细胞的增殖和排列，而不影响XMyoD和XMRF4的表达。它还会导致层粘连蛋白在体节间连接处沉积出现缺陷，而整合素β1亚基的表达和纤连蛋白组装则正常发生。我们的结果表明，Dg对于体节细胞的增殖和伸长都至关重要，并且Dg的胞质结构域是层粘连蛋白在体节间边界处组装所必需的。《发育动力学》238:1332 - 1345，2009年。（c）2008威利 - 利斯公司。
