1. Division of Anatomy, Cell and Human Biology, Division of Physiology (S.R.M.), GKT School of Biomedical Sciences, King’s College London, Guy’s Campus, London, United Kingdom SE1 1UL;
2. AstraZeneca, Central Toxicology Laboratory (A.N.B.), Alderley Park Macclesfield, Cheshire, United Kingdom SK10 4TJ
3. Medical Research Council Human Reproductive Sciences Unit (I.A.S.), Edinburgh, United Kingdom EH3 9ET;