These authors contributed equally: X. Sun, B. Pawlyk.

Berman-Gund Laboratory for the Study of Retinal Degenerations, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, MA, USA

X. Sun, B. Pawlyk, X. Xu, X. Liu, O. V. Bulgakov, M. Adamian, M. A. Sandberg & T. Li

Schepens Eye Research Institute, Harvard Medical School, Boston, MA, USA

S. C. Khani

Department of Genetics, Institute of Ophthalmology, NIHR Biomedical Research Centre, University College London, London, UK

M. -H Tan, A. J. Smith & R. R. Ali