1. The Netherlands Ophthalmic Research Institute, Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105 BA Amsterdam, The Netherlands
2. Retinal Electrodiagnostics Research Group, Department of Ophthalmology, University of Tübingen, Schleichstr. 12-16, 72076 Tübingen, Germany
3. Centre for Developmental Genetics, Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
4. Laboratoire de Neurogenèse et Morphogenèse au cours du Développement et chez l'Adulte (NMDA), UMR 6156 CNRS, IBDM, Université de la Méditerranée, Campus de Luminy, case 907, 13288 Marseille CEDEX 09, France