Skip to main content


Fig. 1 | BMC Evolutionary Biology

Fig. 1

From: Reiterative use of FGF signaling in mesoderm development during embryogenesis and metamorphosis in the hemichordate Ptychodera flava

Fig. 1

FGF ligand genes are dynamically expressed during P. flava embryogenesis. In situ hybridization of fgf8/17/18 (A1-A5), fgfa (B1-B5), fgfb (C1-C5), fgfc (D1-D5) and fgfd (E1-E5) at different embryonic stages. All embryos are shown from a lateral view and oriented with the mouth to the left, except for panel D5. The embryo in D5 is shown from the ventral side. Embryos shown in C3 and D4 were photographed with the focal plane on the ectoderm. Inserts in A4, C3, D4 and D5 are shown from the ventral side, the apical surface, the ventral surface, and the lateral side, respectively. The expression patterns for all ligands are schematically summarized in F1-F7. Each stage is shown and different genes are indicated with different colors. The blue arrowheads in panels A2-A4 and B4-B5 indicate ectodermal expression. Black arrows in B4-B5 indicate the animal part of the protocoel, and the hydroporic canal is indicated by a black arrowhead. The four vertical stripes of fgfb expression are labeled with lowercase letters (a, b, c, and d) in the C3 insert. Two of the four stripes are circled by white dashed lines in C3 and labeled with lowercase letters (a and b), corresponding to the labels in the insert. Red arrows and arrowheads in panels D4-D5 and F6-F7 indicate the expression of fgfc in preoral and postoral ciliary bands. Green arrowheads in E4-E5 indicate the expression of fgfd in the ventral tip of the mesoderm. All panels are shown in the same scale, according to the scale bar in A1

Back to article page