1. MRC Protein Phosphorylation Unit, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, Scotland, UK.
2. Laboratory for Vertebrate Body Plan, Center for Developmental Biology, RIKEN Kobe, Minami-machi, Chuo-ku, Kobe, Japan.
3. Division of Cell Biology and Immunology, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, Scotland, UK.