Xenbase Image ID: 1061

Fig. 8. Individual role of Wnt and FGF signaling in the positioning of the wavefront. (A) RT-PCR analysis of dorsal explants treated with SU5402 or WIF1. Dorsal explants were dissected at stage 14 from the normal embryos and cultured for 1.5 or 3 hours with 0.1% BSA in LCMR containing SU5402 or WIF1. (B) Western blot analysis of MAPK phosphorylation. The dorsal explants were treated with the indicated drug/protein for 1.5 or 3 hours. MAPK phosphorylation was analyzed by anti-dp-ERK Ab (upper panel) and total MAPK by anti-ERK Ab (lower panel). MAPK phosphorylation was reduced by 1.5-3 hours of SU5402 treatment (lanes 2, 5) or 3 hours of WIF1 treatment (lanes 3, 6). (C-C′) Whole-mount in situ hybridization of Arp-A probe. The dorsal explants were isolated from the neural stage normal embryos and treated with SU5402 (C′) or with WIF1 (C′) for 1.5 hours. Reduced Arp-A expression; BSA, 0/20; SU5402, 0/20; WIF1, 14/20. (D-D′) Wholemount in situ hybridization of Thy1 probe. The dorsal explants of the stage 14 normal embryos were treated with SU5402 (D′) or with WIF1 (D′) for 1.5 hours. Upper and lower dashed line indicates S-II/Thy1 and S-III/Thy1 stripes, respectively. (E) Bar graph shows the effect of SU5402, WIF1 and SU5402/WIF1 treatment on the relative distance between S-II/Thy1 and S-III stripes. Gray bar and black dots indicate the average distance and individual distance, respectively. Data are represented as fold change, compared with the average distance of BSA/DMSO-treated explants (=1.0). (F) Summary of the role of Shisa2 in segmentation. The caudorostrally decreasing gradients of Wnt and FGF signal control the maturation of PSM and determine the position where cells transit to the definitive segmental fate (TP: transition point). Shisa2 is expressed strongly in the region covering the TP, but its expression gradually decreases in the caudal PSM. Shisa2 positions the TP by the individual inhibition of the Wnt and FGF signaling. RA positions the TP at least in part by the indirect inhibition of FGF signaling. Image published in: Nagano T et al. (2006) Copyright © 2006. Image reproduced with permission of the publisher and the copyright holder. This is an Open Access article distributed under the terms of the Creative Commons Attribution License. Larger Image Printer Friendly View

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