Fig. 7
From: Tooth and scale morphogenesis in shark: an alternative process to the mammalian enamel knot system
Apoptosis detection in developing tooth and scale buds in the catshark Scyliorhinus canicula. Apoptotic cells (TUNEL, red), actin (phalloidin, green) and DNA (DAPI, blue) were localized by triple labelling and confocal microscopy imaging. Dorsal views of successive z-planes of a whole-mount lower jaw, merged for all three canals (a, buccal surface with taste buds; b, dental epithelium layer of tooth bud 1, late LM; c, dental epithelium layer of tooth bud 2, late LM; d: schematic of the dorsal view). Lateral views of successive planes in a caudal scale, merged for all three canals, early ED (e, scale bud side, z = 6 μm; f, scale bud center, z = 12 μm). Sections through the neural tube merged for all three canals, g negative control without the terminal deoxynucleotidyl transferase (TdT) enzyme, no apoptosis is detected; h positive control after DNAse I digestion, all nuclei are positively stained with both the DAPI and the TUNEL, resulting in purple fake color. White arrowhead: TUNEL positive staining in the buccal epithelium. See Additional files 2 and 3 for all z-planes. Scale bar: 150 μm