Elizabeth S. Maywood,1 Johanna E. Chesham,1 Qing-Jun Meng,2 Patrick M. Nolan,3 Andrew S. I. Loudon,2 and Michael H. Hastings1 1Division of Neurobiology, Medical Research Council (MRC) Laboratory of Molecular Biology, Cambridge, CB2 0QH, United Kingdom, 2Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, United Kingdom, and 3Mammalian Genetics Unit, MRC Harwell, Oxfordshire ...