In vivo analyzes of dystroglycan function during somitogenesis in Xenopus laevis.
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.
Hidalgo
Magdalena
M
Université Pierre et Marie Curie Paris 6 UMR CNRS 7622, Laboratoire de Biologie du Développement, équipe Matrice Extracellulaire et Développement, Paris, France.
Sirour
Cathy
C
Bello
Valérie
V
Moreau
Nicole
N
Beaudry
Michèle
M
Darribère
Thierry
T
D000818:Animals; D049109:Cell Proliferation; D049030:Dystroglycans / Q000235:genetics / Q000378:metabolism*; D017403:In Situ Hybridization; D020287:In Situ Nick-End Labeling; D007797:Laminin / Q000235:genetics / Q000378:metabolism; D009024:Morphogenesis; D024510:Muscle Development / Q000502:physiology; D016376:Oligonucleotides, Antisense / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D019170:Somites / Q000033:anatomy & histology / Q000196:embryology*; D014982:Xenopus laevis / Q000033:anatomy & histology* / Q000196:embryology* / Q000502:physiology
D007797:Laminin; D016376:Oligonucleotides, Antisense; D049030:Dystroglycans