Smed-1H6 and -6G10 co-labeling reveal the complexity of the midline collapse phenotype following slit RNAi. (A-B) Whole-mount view of a planarian bisected sagittally and immunostained 15 dpa with 1H6 (green) and 6G10 (magenta). (A) Image of the ventral nerve cords (VNCs) shows slit(RNAi) worms with intersecting VNCs (arrowheads, 3/5 slit(RNAi), 0/5 gfp(RNAi) animals), as well as slit(RNAi) worms with widely spaced VNC tracks (arrows, (5/5 slit(RNAi), 0/5 gfp(RNAi) animals). (B) Image of the enteric muscles delineating the intestine illustrates fusion of the intestinal branches posterior to the pharynx in slit(RNAi) animals (arrows, 5/5 slit(RNAi) animals, 1/5 gfp(RNAi) animals). Images are maximum intensity projections of optical sections. Anterior is to the left in all images. Scale bar: 200 μm.