1. Section of Molecular Cell and Developmental Biology and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA.
2. Center for Human Disease Modeling, Departments of Cell Biology and Pediatrics, Duke University, Durham, NC 27710, USA.
3. Departments of Ophthalmology, Medicine, Pediatrics, and Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
4. Sections of Ophthalmology and Neurosciences, Leeds Institute of Molecular Medicine, St James's University Hospital, Leeds, LS9 7TF, UK.
5. Département de Génétique, INSERM U781, Hôpital Necker–Enfants Malades, Université Paris Descartes, Paris, France.
6. Howard Hughes Medical Institute, University of Texas at Austin, Austin, TX 78712, USA.