Fig. 4

Expression of endomesodermal, anterior and posterior markers during the embryonic development of Ph. harmeri. WMISH of otx, gsc, six3/6, nk2.1, cdx, bra, foxA, gata4/5/6 and twist in blastula, early gastrulae, late gastrulae, early larvae, pre-tentacle larvae and 6-tentacle larvae of Ph. harmeri. The panels of the first columns (a–bbb) depict embryos in lateral view and the panels of the second columns show embryos in vegetal view (a′–bbb′). Insets in x′, cc′, jj–jj′, nn′, pp and aaa–aaa′ show different focal planes of the embryos. Black arrow indicates the ectodermal expression of otx at the domain that gives rise to the apical organ. The inset in zz′ and pp′ shows different focal planes and higher magnification of the indicated domains. The row below the matrix depicts enlarged images of the insets in x′, cc′, jj–jj′, nn′, pp–pp′, zz′ and aaa–aaa′. In panels depicting gastrulae and larvae stages, anterior is to the left