Quantitation of Melanoblasts in sections through the head and trunk at E13.5.

At least 3 embryos of each genotype were analyzed. For the head, only horizontal sections containing one or both eyes were included. For the trunk, horizontal sections corresponding to regions shown in Figure 3 were included. The standard deviations are included in parentheses. The results of statistical analyses comparing bt9J/+ and bt9J/bt9J are included (NS = not significant and ** = p<0.0001, which is highly significant).