1. Institute of Reproductive and Developmental Biology (S.A.S., S.F., K.H.), Imperial College London, Hammersmith Hospital, London W12 0NN, United Kingdom
2. Department of Mathematics (J.S.), Imperial College London, London SW7 2AZ, United Kingdom
3. Department of Metabolic Medicine (S.M.D.), Imperial College London, Hammersmith Hospital, London W12 0NN, United Kingdom