Inhibition of chondrogenesis by Wnt gene expression in vivo and in vitro. Academic Article uri icon

Overview

abstract

  • The Wnt family of secreted signaling proteins are implicated in regulating morphogenesis and tissue patterning in a wide variety of organ systems. Several Wnt genes are expressed in the developing limbs and head, implying roles in skeletal development. To explore these functions, we have used retroviral gene transfer to express Wnt-1 ectopically in the limb buds and craniofacial region of chick embryos. Infection of wing buds at stage 17 and tissues in the head at stage 10 resulted in skeletal abnormalities whose most consistent defects suggested a localized failure of cartilage formation. To test this hypothesis, we infected micromass cultures of prechondrogenic mesenchyme in vitro and found that expression of Wnt-1 caused a severe block in chondrogenesis. Wnt-7a, a gene endogenously expressed in the limb and facial ectoderm, had a similar inhibitory effect. Further analysis of this phenomenon in vitro showed that Wnt-1 and Wnt-7a had mitogenic effects only in early prechondrogenic mesenchyme, that cell aggregation and formation of the prechondrogenic blastema occurred normally, and that the block to differentiation was at the late-blastema/early-chondroblast stage. These results indicate that Wnt signals can have specific inhibitory effects on cytodifferentiation and suggest that one function of endogenous Wnt proteins in the limbs and face may be to influence skeletal morphology by localized inhibition of chondrogenesis.

publication date

  • May 1, 1997

Research

keywords

  • Cartilage
  • Gene Expression Regulation, Developmental
  • Proto-Oncogene Proteins
  • Zebrafish Proteins

Identity

Scopus Document Identifier

  • 0031149422

Digital Object Identifier (DOI)

  • 10.1006/dbio.1997.8536

PubMed ID

  • 9169054

Additional Document Info

volume

  • 185

issue

  • 1