A novel role for a nodal-related protein; Xnr3 regulates convergent extension movements via the FGF receptor.
Convergent extension behaviour is critical for the formation of the vertebrate body axis. In Xenopus, components of the Wnt signaling pathway have been shown to be required for convergent extension movements but the relationship between cell fate and morphogenesis is little understood. We show by loss of function analysis that Xnr3 activates Xbra expression through FGFR1. We show that eFGF activity is not essential in the pathway, and that dishevelled acts downstream of Xnr3 and not in a parallel pathway. We provide evidence for the involvement of the EGF-CFC protein FRL1, and suggest that the pro-domain of Xnr3 may be required for its activity. Since Xnr3 is a direct target of the maternal betacatenin/XTcf3 signaling pathway, it provides the link between the initial, maternally controlled, allocation of cell fate, and the morphogenetic movements of cells derived from the organizer.
Yokota
Chika
C
Division of Developmental Biology, Cincinnati Children's Research Foundation, 3333 Burnet Avenue, Cincinnati, Ohio 45229-3039, USA.
Kofron
Matt
M
Zuck
Mike
M
Houston
Douglas W
DW
Isaacs
Harry
H
Asashima
Makoto
M
Wylie
Chris C
CC
Heasman
Janet
J
D000818:Animals; D015415:Biomarkers; D019521:Body Patterning / Q000502:physiology*; D002465:Cell Movement / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D006023:Glycoproteins; D036341:Intercellular Signaling Peptides and Proteins; D016376:Oligonucleotides, Antisense / Q000378:metabolism; D009865:Oocytes / Q000502:physiology; D020897:Organizers, Embryonic / Q000502:physiology; D010641:Phenotype; D011506:Proteins / Q000378:metabolism; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D051496:Receptor, Fibroblast Growth Factor, Type 1; D017468:Receptors, Fibroblast Growth Factor / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D020825:T-Box Domain Proteins / Q000235:genetics / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism*; D029867:Xenopus Proteins / Q000235:genetics / Q000378:metabolism; D014982:Xenopus laevis / Q000196:embryology* / Q000502:physiology
D015415:Biomarkers; D006023:Glycoproteins; D036341:Intercellular Signaling Peptides and Proteins; D016376:Oligonucleotides, Antisense; D011506:Proteins; D017468:Receptors, Fibroblast Growth Factor; D020825:T-Box Domain Proteins; C116765:TBXT protein, Xenopus; D016212:Transforming Growth Factor beta; D029867:Xenopus Proteins; C094620:nodal3.1 protein, Xenopus; C054234:chordin; D020794:Receptor Protein-Tyrosine Kinases; D051496:Receptor, Fibroblast Growth Factor, Type 1