Xenopus msx1 mediates epidermal induction and neural inhibition by BMP4.
Epidermal fate in Xenopus ectoderm has been shown to be induced by a secreted growth factor, Bone Morphogenetic Protein 4 (BMP4). However, the molecular mechanism mediating this response is poorly understood. Here, we show that the expression of the homeobox gene, msx1, is an immediate early response to BMP4 in Xenopus embryos. The timing of expression and embryonic distribution of msx1 parallel those described for BMP4. Moreover, overexpression of msx1 in early Xenopus embryos leads to their ventralization as described for BMP4. Consistent with mediating a BMP type of signaling, overexpression of msx1 is sufficient to induce epidermis in dissociated ectoderm cells, which would otherwise form neural tissue. Finally, msx1 can also rescue neuralization imposed by a dominant negative BMP receptor (tBR) in ectodermal explants. We propose that Xenopus msx1 acts as a mediator of BMP signaling in epidermal induction and inhibition of neural differentiation.
Suzuki
A
A
Laboratory of Molecular Embryology, The Rockefeller University, New York, NY 10021-6399, USA.
Ueno
N
N
Hemmati-Brivanlou
A
A
D000818:Animals; D019521:Body Patterning / Q000235:genetics; D055415:Bone Morphogenetic Protein 4; D052004:Bone Morphogenetic Protein Receptors; D019485:Bone Morphogenetic Proteins / Q000235:genetics / Q000494:pharmacology*; D003513:Cycloheximide / Q000494:pharmacology; D004475:Ectoderm / Q000737:chemistry; D004627:Embryonic Induction / Q000235:genetics*; D004817:Epidermis / Q000196:embryology*; D005775:Gastrula / Q000737:chemistry; D018507:Gene Expression Regulation, Developmental; D005801:Genes, Homeobox / Q000502:physiology; D018398:Homeodomain Proteins / Q000235:genetics / Q000502:physiology*; D051957:MSX1 Transcription Factor; D009420:Nervous System / Q000737:chemistry / Q000196:embryology*; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis; D011956:Receptors, Cell Surface / Q000235:genetics / Q000502:physiology; D017978:Receptors, Growth Factor; D014157:Transcription Factors; D014981:Xenopus; D029867:Xenopus Proteins
D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins; D018398:Homeodomain Proteins; D051957:MSX1 Transcription Factor; C497996:MSX1 protein, Xenopus; D011500:Protein Synthesis Inhibitors; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D017978:Receptors, Growth Factor; D014157:Transcription Factors; D029867:Xenopus Proteins; C525812:bmp4 protein, Xenopus; D003513:Cycloheximide; D052004:Bone Morphogenetic Protein Receptors