Fig. 3. Wee2 is required for anterior-posterior embryo elongation, somite formation, and convergent extension. (A) Wee2-depleted embryos fail to extend along the anteroposterior axis and fail to form somites. Embryos were treated as in Fig. 2D, but allowed to develop until the controls reached stage 25 before being processed for MyoD in situ analysis. Anterior towards the right, dorsal towards the top. Labels as in Fig. 1A. Scale bar: 300 µm. (B) Unilateral depletion of Wee2. One blastomere (asterisk) of a two-cell embryos was microinjected with 40 ng CMO or W2MO.1. These were allowed to develop until controls reached stage 19 and photographed. Dorsal view, anterior towards the top. Note curvature and reduced somitic ridge (arrow) on the Wee2-depleted side. (C) Mesoderm specific gene expression is unchanged in Wee2-depleted embryos. Quantitative RT-PCR for MyoD, XNot, Vent1, MA, MHC and ornithine decarboxylase (ODC) from whole, stage 18 embryos treated with W2MO.1, CMO or nothing (Sibling). (D) Depletion of Wee2 compromises convergent extension driven elongation of dorsal explants. Embryos were treated with W2MO.1 or CMO as in Fig. 2D and then processed for dorsal explants. Explants were photographed when controls reached stage 26. Scale bar: 1 mm.