1. Institute of Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany;
2. European Xenopus Resource Centre, School of Biological Sciences, University of Portsmouth, Portsmouth, United Kingdom;
3. Ambystoma Mexicanum Bioregeneration Center, Department of Plastic, Aesthetic, Hand and Reconstructive Surgery, Hannover Medical School, Medizinische Hochschule Hannover, Hannover, Germany