Fig. 5. Morphological effects of spaw knockdown. (A-D) Uninjected and Spaw-MO1-injected embryos (10 ng), 55-60 hours post-fertilization embryos. (A) Lateral view, anterior towards the left. Asterisks indicate posterior end of yolk tube extension. (B,C) Higher magnifications of embryos in A, focusing on somites and notochord. (D) Dorsal view, anterior towards the left. (E) Sixty to 70% epiboly, Dig-gsc probe, dorsal view. Uninjected embryo (left); embryo injected with 10 ng Spaw-MO1 (right). (F-H) Ventral anterior view of 30 hours post-fertilization embryos injected with 6 ng Spaw-MO1. Dig-nkx2.5 probe shows the heart tube (arrowheads). Hearts exhibit left jog (F), no jog (G) or right jog (H). (I,J) MF20 myosin antibody staining highlighting normal D-looping (I) and reversed L-looping (J) of the heart in two embryos injected with 10 ng each of Spaw-MO1. Ventral views, 60 hours post-fertilization. The ventricle (arrowhead) stains more intensely. (K,L) Dorsal view of 48 hours post-fertilization embryos (anterior towards the left), Dig-preproinsulin probe, right (K) and left (L) displacements of the pancreas (arrowheads) from the midline. R, right side; L, left side.