Fig. 5

Expression of NK3 and NK4 at late developmental stages in embryos of the onychophoran E. rowelli. Anterior is left in A, D, D′, E, E′ and up in B, C, F, F′, G; developing legs are numbered. A Stage IV embryo in lateral view. B Head of stage VI embryo in dorsal view. C Anterior region of stage VI embryo in ventral view. Arrowheads point to the expression in the anlagen of ventral nerve cords. D Developing slime papilla and first two legs of a stage IV embryo in lateral view. Anterior and posterior NK3 domains are marked with empty and filled arrowheads, respectively. D′ Third to fifth developing legs of a stage IV embryo in lateral view. Anterior and posterior NK3 domains are marked with empty and filled arrowheads, respectively. E Stage IV embryo in lateral view. Empty arrowheads indicate the expression along the dorsal rims of the lateral germ bands. E′ Superimposed light micrograph and DAPI image of the same embryo as in E. F Posterior end of a stage IV embryo in dorsal view. Arrowheads point to the expression along the dorsal rims of the lateral germ bands. F′ Superimposed light micrograph and DAPI image of the same embryo as in F. G Detail of the 12th and 13th legs in dorsal view. Asterisks indicate the mesodermal NK4 domains. Abbreviations: at, developing antenna; cl, cephalic lobe; cn, central brain neuropil; de, dorsal extra-embryonic tissue; jw, developing jaw; po, proctodeum; sp, developing slime papilla; ve, ventral extra-embryonic tissue. Scale bars: A, E, E′: 500 µm; D, D′, G: 100 µm; B, C, F, F′: 200 µm