1. Department of Anatomy and Embryology, Veterinary Faculty, Autonomous University of Barcelona, 08193-Bellaterra, Spain
2. Laboratory of Teratology, Centro de Investigación y Desarrollo Aplicado, SAL 08130-Santa Perpetua de la Mogoda, Barcelona, Spain
3. Department of Pharmacology and Toxicology, Veterinary Faculty, Autonomous University of Barcelona, 08193-Bellaterra, Spain
4. Laboratory of Anatomy and Teratology, Ecole Nationale Vétérinaire, 23 Chemin des Capelles, F-31076 Toulouse, Cedex, France