Figure 7
Carapacial patterning of HNK-1-positive migratory neural crest cells and pigmentation. (A) At G18, HNK-1 positive cells were localized to the sulci (black arrow), leaving the scutes (*) free. (B) The migratory neural crest cell inhibitor PNA was expressed in a mutually exclusive pattern to the HNK1-positive cells; PNA was localized to the scutes (*) leaving the sulci free (black arrow). (C) At G19, the carapacial HNK-1 positive cells were located in the sulci between the scutes (red arrow) and as paired spots (black circle) on both sides of the spine on the anterior end of the vertebral scutes. These areas were PNA-free in (B). (D) The pattern of pigment at G23 matched the pattern of HNK-1 at G18 and G19. Anterior is to the right in all images. Scale bars 1 mm (A,D), and 2 mm (B,C). The second costal scute on the right side of the carapace is marked by an asterisk (*) in all specimens. Black arrows indicate the sulcus between the second and the third costal scutes (A,B). Red arrows indicate the sulcus between the fourth costal and the fourth vertebral scutes (C,D). The black circle shows one of the paired HNK1-positive migratory neural crest cell spots on the fourth vertebral scute in (C), and the same location of pigment in (D).
