Department of Biology, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany and Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK.|Department of Biology, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany and Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK.|Department of Biology, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany and Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK.|Department of Biology, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany and Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK.