1. Laboratory for Vertebrate Body Plan, Center for Developmental Biology (CDB), RIKEN Kobe; Chuo-ku Kobe Japan
2. Misaki Marine Biological Station, Graduate School of Science, The University of Tokyo; Misaki, Miura Kanagawa Japan
3. Animal Development and Differentiation Research Unit, Animal Research Division, National Institute of Agrobiological Sciences (NIAS); Tsukuba-shi Ibaraki Japan
4. Laboratory of Animal Reproduction, Department of Animal Science and Resources, Nihon University College of Bioresource Sciences; Fujisawa Kanagawa Japan
5. Ultrastructural Research Team, Biosystem Dynamics Group, Division of Bio-function Dynamics Imaging, RIKEN Center for Life Science Technologies (CLST); Chuo-ku Kobe Japan
6. Laboratory for Animal Resources and Genetic Engineering, Center for Developmental Biology (CDB), RIKEN Kobe; Chuo-ku Kobe Japan