xCdc4ΔFbox impairs melanocyte development. xCdc4ΔFbox, xCdc4 or control GFP mRNA (0.5 ng) were injected into each of the two dorsal cells of four-cell-stage embryos. (A-C)Embryos were allowed to develop to stage 43 and subsequently the distribution and number of melanocytes were compared: xCdc4ΔFbox (A), xCdc4 (B) and GFP (C). (A-C) Representative embryos are shown (lateral views, anterior side right). (D)The average number of melanocytes for each condition was calculated and the mean ± standard error of the mean from two independent experiments are shown (n = 31 to 57). There was a significant decrease in the number of melanocytes following injection with xCdc4ΔFbox when compared to GFP or xCdc4 (***P << 0.0001), and a smaller decrease following injection with xCdc4 when compared to injection with GFP (*P < 0.01).