title: Pou-V factor Oct25 regulates early morphogenesis in Xenopus laevis.
abstract: POU-V class proteins like Oct4 are crucial for keeping cells in an undifferentiated state. An Oct4 homologue in Xenopus laevis, Oct25, peaks in expression during early gastrulation, when many cells are still uncommitted. Nevertheless, extensive morphogenesis is taking place in all germ layers at that time. Phenotypical analysis of embryos with Oct25 overexpression revealed morphogenesis defects, beginning during early gastrulation and resulting in spina-bifida-like axial defects. Analysis of marker genes and different morphogenesis assays show inhibitory effects on convergence and extension and on mesoderm internalization. On a cellular level, cell-cell adhesion is reduced. On a molecular level, Oct25 overexpression activates expression of PAPC, a functional inhibitor of the cell adhesion molecule EP/C-cadherin. Intriguingly, Oct25 effects on cell-cell adhesion can be restored by overexpression of EP/C-cadherin or by inhibition of the PAPC function. Thus, Oct25 affects morphogenesis via activation of PAPC expression and subsequent functional inhibition of EP/C-cadherin.
authors.affiliation: Institute of Biochemistry, University of Ulm, 89081, Ulm, Germany.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Julier
authors.forename: Claudio
authors.initials: C
authors.lastname: Goll
authors.forename: Brigitte
authors.initials: B
authors.lastname: Korte
authors.forename: Walter
authors.initials: W
authors.lastname: Knöchel
authors.forename: Stephan A
authors.initials: SA
authors.lastname: Wacker
mesh_terms: D000818:Animals; D015820:Cadherins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D002448:Cell Adhesion / Q000502:physiology; D054262:Gastrulation / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D008648:Mesoderm / Q000166:cytology / Q000196:embryology*; D009024:Morphogenesis / Q000502:physiology*; D050809:POU Domain Factors / Q000096:biosynthesis* / Q000235:genetics; D000091363:Protocadherins; D029867:Xenopus Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D014982:Xenopus laevis
chemical_list: C074260:CDH3 protein, Xenopus; D015820:Cadherins; D050809:POU Domain Factors; C117635:Pcdh8 protein, Xenopus; D000091363:Protocadherins; D029867:Xenopus Proteins