Expression of chick Barx-1 and its differential regulation by FGF-8 and BMP signaling in the maxillary primordia
✍ Scribed by Amanda J. Barlow; Jean-Philippe Bogardi; Raj Ladher; Philippa H. Francis-West
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 252 KB
- Volume
- 214
- Category
- Article
- ISSN
- 1058-8388
No coin nor oath required. For personal study only.
✦ Synopsis
The vertebrate face develops from a series of primordia surrounding the primitive mouth and is thought to be patterned by the differential expression of homeobox-containing genes. Here we describe the isolation of the chick homologue of the homeobox-containing gene, Barx-1, and show its expression in the developing facial primordia, stomach, and appendicular skeleton. In the maxillary primordia, mesenchymal expression of Barx-1 is complementary to that of Msx-1, which correlate with overlying epithelial expression of Fgf-8 and Bmp-4, respectively. We show that epithelial signals are required to maintain Barx-1 expression and that FGF-8 can substitute for the epithelium. By contrast, BMPs reduce Barx-1 expression and can antagonize FGF-8 signaling. This suggests that in vivo, FGF-8/BMP signaling may regulate Barx-1 gene expression. This provides evidence that the differential expression of FGF-8 and BMPs may determine homeobox-containing gene expression and hence patterning of the facial primordia.