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Fig. 6.
Effects of manipulating Notch1 activity on the ventral center gene bmp4. (A-L) ISH expression pattern of bmp4 in embryos in which the Notch pathway was stimulated (B-D,F) or blocked (H,J-L). Corresponding sibling uninjected controls (A,E,I) or control Mo-injected sibling (G). Insets show the green fluorescence of the co-injected tracer DOG. (B-D) Embryos unilaterally injected with 1 ng of nicd1 mRNA into one cell at the two-cell stage. Bmp4 was upregulated on the injected side in comparison with the non-injected side in some cases (B, 44%, n=62; green asterisk), but it was downregulated in others (D, 48%, n=62; red asterisk) and it was unaffected in a low proportion of the injected embryos (C, 8%, n=62; yellow asterisk). (F) Embryo injected with 1 ng of notch1 FL mRNA at the one-cell stage, showing the strong upregulation of bmp4 in comparison with uninjected sibling controls (E). (G,H) Sibling embryos unilaterally injected with 30 ng of control Mo (G) or with 30 ng of Notch1 Mo (H) into one cell at the two-cell stage. Bmp4 was completely downregulated on the injected side in H. (J-L) Unilateral injection of 1 ng of su(H)1DBM mRNA into one cell at the two-cell stage leads to variable results in bmp4 expression when comparing the injected- with the non-injected side: (J) 50% downregulated (red arrow), (K) 27% unaffected (yellow arrow), (L) 23% upregulated (green arrow). Black arrows point to the dorsal/ventral limit of the bmp4 domain on the non-injected side. (M) Summary of ISH results, expressed as the percentage of embryos showing the changes in bmp4 expression indicated by the color codes [cyan, upregulated; orange, downregulated; gray, without changes (W/C)]. The number of total embryos analyzed (n) and the number of independent experiments (Exp) are indicated for each bar. (N) Quantification of bmp4 mRNA by RT-qPCR at s10 and s11. Data are mean+s.e.m. *P<0.05 (one-way ANOVA analysis compared with control Mo injection). s, stage. |
