1. Stowers Institute for Medical Research, 1000 East 50th St, Kansas City, MO 64110, USA.
2. Oxford University, Centre for Mathematical Biology, Mathematical Institute, University of Oxford, 24-29 St Giles’, Oxford OX1 3LB, UK.
3. Oxford Centre for Integrative Systems Biology, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK.
4. Department of Anatomy and Cell Biology, University of Kansas School of Medicine, Kansas City, KS 64157, USA.