Fig. S3

Fig. S3

Controls of global and selective FGF perturbations, related to Figure 4

(A-A’’) Time lapse of somite segmentation and MPs differentiation under SU5402 treatment at 60μM. Embryo was treated with SU5402 at 19-somite stage and then mounted for live imaging at 20-somite stage (A) abnormally large somite appeared at 24th somite after 4-5 rounds of somite formation after treatment of SU5402 (A’). MPs are identified at 460 mins after somite segmentation by Eng2a:eGFP (A’’). (B) Graphic representation of MPs number and somite AP length from somite 19 to somite 24 in (A’’). (C and C’) Dorsalisation phenotypes are observed at 10 hpf after injection of cafgfr1 mRNA at one cell stage. (D and D’) Loss of trunk and tail are observed at 17 hpf after injection of dnfgfr1 mRNA into embryos at one cell stage. (E and F) Controls of mosaic FGF perturbations driven by smyhc1:gal4;UAS:mCherry (E) or hsp70l:mCherry (F) respectively. (E’ and F’) Reconstructed transverse view of (E and F) with dorsal to the top and lateral to the left. (G) Fraction of mCherry positive MPs among mCherry positive slow muscles in control group (42/181), FGF inhibited group (38/143) and FGF over-activated group (35/137). (H) Distribution of the number of MPs per muscle segment in wild type embryos (nSomites=55), embryos under mosaic over-activation of FGF signalling (restricted in the fast muscles instead of slow muscles in the corresponding muscle segments) (nSomites=32) and embryos under global over-activation of FGF signalling (nSomites=40). NSp > 0.05 , ***p < 0.001, Student’s t test.