1. Laboratory for Cell Asymmetry, at RIKEN Center for Developmental Biology, 2-2-3 Minatojima-Minamimachi, Chuou-ku, Kobe 650-0047, Japan.
2. Laboratory for Animal Resources and Genetic Engineering, at RIKEN Center for Developmental Biology, 2-2-3 Minatojima-Minamimachi, Chuou-ku, Kobe 650-0047, Japan.
3. Laboratory for Neuronal Differentiation and Regeneration, at RIKEN Center for Developmental Biology, 2-2-3 Minatojima-Minamimachi, Chuou-ku, Kobe 650-0047, Japan.