Fig. 4

Fig. 4 Tbx16 expression in tbx16 morphant, DFC^{tbx16 MO} and yolk^{tbx16 MO} embryos. All panels are dorsal views between 70% and 90% epiboly stages. In uninjected embryos (A–D), fluorescent immunostaining detected Tbx16 protein (green) in margin cells, paraxial mesoderm and DFCs (arrowhead in panels B–D). In Tbx16 morphants (E–H), tbx16 MO was distributed to all embryonic cells (E) and Tbx16 expression was greatly reduced or absent (F). Two representative DFC^{tbx16 MO} embryos are shown (I–P), in which tbx16 MO localized to nuclei in the yolk cell (arrows in panels I, M) and loaded into DFCs (arrowheads in panels I, M). In a portion of DFC^{tbx16 MO} embryos (I–L), tbx16 MO blocked Tbx16 expression in all DFCs without affecting its expression in margin cells or paraxial mesoderm. In other DFC^{tbx16 MO} embryos (M–P), Tbx16 expression was abrogated in a subset of DFCs (arrowhead in panels O, P), but remained normal in other DFCs (arrow in panels O, P). In yolk^{tbx16 MO} embryos, tbx16 MO localized to yolk nuclei (arrows in panel Q), but did not enter DFCs or affect Tbx16 expression in DFCs (arrowhead in panel N) or other embryonic cells. Panels D, H, L, P and T show a close-up of DFCs from merged images.