title: Wnt/beta-catenin signaling controls Mespo expression to regulate segmentation during Xenopus somitogenesis.
abstract: The vertebral column is derived from somites, which are transient segments of the paraxial mesoderm that are present in developing vertebrates. The strict spatial and temporal regulation of somitogenesis is of crucial developmental importance. Signals such as Wnt and FGF play roles in somitogenesis, but details regarding how Wnt signaling functions in this process remain unclear. In this study, we report that Wnt/beta-catenin signaling regulates the expression of Mespo, a basic-helix-loop-helix (bHLH) gene critical for segmental patterning in Xenopus somitogenesis. Transgenic analysis of the Mespo promoter identifies Mespo as a direct downstream target of Wnt/beta-catenin signaling pathway. We also demonstrate that activity of Wnt/beta-catenin signaling in somitogenesis can be enhanced by the PI3-K/AKT pathway. Our results illustrate that Wnt/beta-catenin signaling in conjunction with PI3-K/AKT pathway plays a key role in controlling development of the paraxial mesoderm.
authors.affiliation: Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, and Graduate School of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China.
authors.forename: Jinhu
authors.initials: J
authors.lastname: Wang
authors.forename: Shangwei
authors.initials: S
authors.lastname: Li
authors.forename: Yuelei
authors.initials: Y
authors.lastname: Chen
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Ding
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000096:biosynthesis* / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D019869:Phosphatidylinositol 3-Kinases / Q000502:physiology; D011401:Promoter Regions, Genetic; D051057:Proto-Oncogene Proteins c-akt / Q000502:physiology; D015398:Signal Transduction; D019170:Somites / Q000502:physiology*; D051153:Wnt Proteins / Q000378:metabolism / Q000502:physiology*; D014981:Xenopus / Q000196:embryology / Q000502:physiology*; D029867:Xenopus Proteins / Q000096:biosynthesis* / Q000235:genetics; D051176:beta Catenin / Q000378:metabolism / Q000502:physiology*
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; D051153:Wnt Proteins; D029867:Xenopus Proteins; D051176:beta Catenin; C534575:Msgn1 protein, Xenopus