Fig. 3. Somite segmentation mutants still have early molecular segmentation. (A-D) cs131 in situ hybridization at 10-15 somites; (E-G) her1 in situ hybridization at 8-15 somites. Wild-type embryos (A,E) and fss;yot mutants (B,F) all have presomitic mesoderm stripes of both cs131 and her1; Df^b380 mutants have presomitic mesoderm stripes of her1 (G) but not cs131 (C); and Df^b567 mutants have a presomitic mesoderm stripe of cs131 (the her1 gene is deleted in these mutants). In wild-type embryos, there are also weak somitic stripes of cs131, but these do not form in fss;yot, Df^b380 or Df^b567 mutants. Scale bar: 40 µm.