Fig. 2. Targeted injections of mutant Xdsh elicits distinctly different phenotypes. (A) Injection of Xdsh-D2 into the dorsal animal blastomeres at the eight-cell stage targets expression predominately to the neural ectoderm (blue); injection into the dorsal vegetal blastomeres targets expression to the dorsal axial mesoderm (red). (B) Control embryos at stage 20. (C) Dorsal-animal injection of Xdsh-D2 inhibits neural tube closure, and neural plates remain partially open at stage 20 (arrow). In other cases, neural plates close but fail to fuse normally (arrowhead). (D) Embryos injected dorsovegetally close their neural tubes normally; however, a few do display improper fusion of the neural folds (arrowhead). (E) Control embryos at stage 30. (F) At stage 30, embryos expressing Xdsh-D2 in the neural ectoderm exhibit a severe dorsal flexure and failure to straighten the A/P axis. (G) At stage 30, embryos expressing Xdsh-D2 in the mesoderm do not display dorsal flexure, but instead fail to elongate and are shorter and wider than controls. (H) Control embryo at stage 30. (I) Embryos injected with Xdd1 animally at the eight-cell stage. (J) Embryos injected vegetally at the eight-cell stage with Xdd1.
