1. Univ Rennes, CNRS, IGDR (Genetics and Development Institute of Rennes), UMR 6290, F-35000 Rennes, France
2. Univ Paris Sud, CNRS, LCP (Laboratoire de Chimie Physique), UMR 800, F-91400 Orsay, France
3. Univ Rennes, BIOSIT, UMS CNRS 3480, US INSERM
018, F-35000 Rennes, France