Fig. S3
Sawtooth Cdh2 stabilization is downstream of patterning by the segmentation clock and regulates EphA4 phosphorylation; related to Figure 4. (A) Injection of 200 µM fssmo [S1] inhibits the formation of sawtooth gradients of Cdh2 stability in cdh2-sfGFPTagRFP transgenic embryos (n=11). (B) Loss of cdh2 does not affect activation/phosphorylation of EphA4 at somite boundaries, but does increase EphA4 activation within the mesenchymal core of somites. An average of 55.4% of somites in cdh2-/- embryos exhibited mesenchymal EphA4 phosphorylation (n=25 embryos) vs. 26.9% in (n=28) sibling control embryos (p<0.001, Mann-Whitney-Wilcoxon test). (C) The segmental pattern of EphrinB2A remains in cdh2-/- embryos (n=9). (D) EphrinB2A colocalizes with stable Cdh2 in the posterior somite (n=29). Scale bar = 20 µm.