Fig. 3

Effect of gadd45β MOs on somite segmentation. MOs (control-MO, 15 ng; GADD45β1-MO + GADD45β2-MO, 7.5 ng each) were injected into one- or two-cell-stage embryos. Dorsal view, anterior is up (A–C and J–L). Posterior view, dorsal is up (D–I). Lateral view, anterior is left (M–O). (A–C) Live embryos at 8- or 10-somite stages. Injection of GADD45β1-MO plus GADD45β2-MO, but not control-MO, caused severe defects in somite segmentation (A–C). (D–O) Whole-mount in situ hybridization with probes are shown at the upper right of each micrograph. Expression of mesp-a and her1 in the anterior PSM and segmental expression of MyoD and fgf8 (red asterisk) in the somites were disorganized in the GADD45β1-MO + GADD45β2-MO-injected embryos (D–O). Expression of fgf8 in the PSM (red bracket) was expanded in the double GADD45β MO-injected embryos (M–O).