Fig. 7
Expression of NK6.1 at consecutive developmental stages in embryos of the onychophoran E. rowelli. Anterior is left in A–D, G, H; developing legs are numbered. Insets in A–D show the corresponding embryos stained with DAPI. A Stage I embryo in ventral view. Note the expression around the proctodeum (empty arrowheads) and the closing blastoporal slit (filled arrowheads). Arrows with dashed lines indicate decreasing signal toward the posterior. B Detail of proctodeum (empty arrowheads) and blastoporal slit (filled arrowheads) in the same embryo as in A. C Stage II embryo in lateral view. D Same embryo as in C in ventral view. Note the expression around the proctodeum (arrowheads). E Cross section of a stage II embryo, dorsal is up. Arrowhead point to the NK6.1 expression in the ventrolateral ectoderm. Dotted line demarcates the developing nerve cord. F Same cross section as in E stained with DAPI. G Stage III embryo in lateral view. Note the decreasing signal from anterior to posterior (arrow with dashed line). H Same embryo as in E in ventral view. Small anterior and large posterior domains in the ventral ectodermal thickenings are indicated by arrowheads and asterisks, respectively. Abbreviations: as, antennal segment; at, developing antenna; cl, cephalic lobe; de, dorsal extra-embryonic tissue; js, jaw segment; jw, developing jaw; po, proctodeum; sp, developing slime papilla; ss, slime papilla segment; ve, ventral extra-embryonic tissue. Scale bars: A–D, G, H: 200 µm; E, F: 50 µm