|
|
|
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
Development, Vol 124, Issue 6 1179-1189, Copyright © 1997 by Company of Biologists
JOURNAL ARTICLES |
SE Witta and SM Sato
Genetics and Biochemistry Branch, NIDDK, NIH, Bethesda, MD 20892-1766, USA.
XIPOU 2, a member of the class III POU-domain family, is expressed initially at mid-blastula transition (MBT) and during gastrulation in the entire marginal zone mesoderm, including Spemann's Organizer (the Organizer). To identify potential targets of XIPOU 2, the interaction of XIPOU 2 with other genes co-expressed in the Organizer was examined by microinjecting XIPOU 2's mRNA into the lineage of cells that contributes to the Organizer, head mesenchyme and prechordal plate. XIPOU 2 suppresses the expression of a number of dorsal mesoderm-specific genes, including gsc, Xlim-1, Xotx2, noggin and chordin, but not Xnot. As a consequence of the suppression of dorsal mesoderm gene expression, bone morphogenetic factor-4 (Bmp-4), a potent inducer of ventral mesoderm, is activated in the Organizer. Gsc is a potential target of XIPOU 2. XIPOU 2 is capable of binding a class III POU protein binding site (CATTAAT) that is located within the gsc promoter, in the activin-inducible (distal) element. Furthermore, XIPOU 2 suppresses the activation of the gsc promoter by activin signaling. At the neurula and tailbud stages, dorsoanterior structures are affected: embryos displayed micropthalmia and the loss of the first branchial arch, as detected by the expression of pax-6, Xotx2 and en-2. By examining events downstream from the Wnt and chordin pathways, we determined that XIPOU 2, when overexpressed, acts specifically in the Organizer, downstream from GSK-3beta of the Wnt pathway and upstream from chordin. The interference in dorsalizing events caused by XIPOU 2 was rescued by chordin. Thus, in addition to its direct neuralizing ability, in a different context, XIPOU 2 has the potential to antagonize dorsalizing events in the Organizer.
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati 
Twitter What's this?
This article has been cited by other articles:
|
|
 |
|
  M. Ilia, C. Beasley, D. Meijer, R. Kerwin, D. Cotter, I. Everall, and J. Price Expression of Oct-6, a POU III Domain Transcription Factor, in Schizophrenia Am J Psychiatry, July 1, 2002; 159(7): 1174 - 1182. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. A. Seville, S. Nijjar, M. W. Barnett, K. Masse, and E. A. Jones Annexin IV (Xanx-4) has a functional role in the formation of pronephric tubules Development, January 4, 2002; 129(7): 1693 - 1704. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Brennan, S Nijjar, and E. Jones The specification and growth factor inducibility of the pronephric glomus in Xenopus laevis Development, January 12, 1999; 126(24): 5847 - 5856. [Abstract] [PDF]
|
|
|
|
 |
|
 A K Ryan and M G Rosenfeld POU domain family values: flexibility, partnerships, and developmental codes. Genes & Dev., May 15, 1997; 11(10): 1207 - 1225. [PDF]
|
|
