QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

Help viewing high resolution images Return to article

Fig. 4. Wnt activity in DV patterning is independent of Bmp but dependent on Shh/Gli activity. (A,B) HH stage 11/12 embryos were electroporated with Wnt1 and Wnt3a, and analysed 24 hours PE, for the expression of Bmp4 and Bmp7 by in situ hybridization. (A) Bmp4 expression was weakly expanded ventral to the roof plate. (B) Ectopic Bmp7 expression was induced on the electroporated side. (C) Electroporation of chick noggin resulted in the loss of Lhx2/9-expressing dI1. (D,E) Noggin electroporation alone did not modify dorsal expression of Pax7. (F) Co-electroporation of Wnt1/3a with noggin resulted in the expansion of Pax7 expression. (G,H) Noggin electroporation alone resulted in the wild-type expression of Olig2 and Nkx2.2. (I) Co-electroporation of Wnt1/3a with noggin resulted in the reduction of Olig2 (green) and Nkx2.2 (red) expression. (J-L) HH stage 11/12 embryos electroporated with Wnt1/3a were analysed 8 or 24 hours PE for the expression of Gli3 and Gli2 by in situ hybridization. (J) Eight hours PE of Wnt1/Wnt3a there was a moderate ventral expansion of Gli3 expression. (K) Twenty-four hours PE, over- and ectopic expression of Gli3 occurred. (L) Twenty-four hours PE there was overgrowth of the electroporated side without a change in expression of Gli2. (M-R) Wnt regulation of progenitor gene expression is dependent on Gli activity. (M) Twenty-four hours PE of Gli^ZnF alone there was no modification of Pax7 expression (N,O) Co-electroporation of Gli^ZnF abolished Wnt-induced ventral expansion of Pax7. (O) GFP as a reporter of transgene expression. (P) Twenty-four hours PE, Gli^ZnF alone reduced Nkx2.2 (red) expression. (Q,R) Co-electroporation of Wnt1/3a and Gli^ZnF resulted in a partial rescue of Olig2 (green) and Nkx2.2 (red) expression. (S) Quantitative analysis of Olig2+ and Nkx2.2+ cells on electroporated versus non-electroporated side of the spinal cord (24 hours PE of indicated DNAs). (T) In vivo quantitative analysis of the transcriptional activities for several components of the Wnt/β-catenin and the Shh/Gli pathways on a Tcf (TopFlash) transcriptional reporter. Embryos were electroporated with the indicated DNAs. Graph shows normalized luciferase units. Gli^ZnF had no positive effect on the TopFlash reporter and cannot repress Wnt-induced luciferase. Electroporation of Tcf^HMG blocked all induced luciferase activity.

Return to article