ISE-M, Universitxc3xa9 Montpellier, CNRS, IRD, EPHE, Montpellier, France.|Department of Mathematics, Simon Fraser University, Burnaby, BC, Canada.|ELTE-MTA Lendxc3xbclet Biophysics Research Group, Budapest, Hungary.|LIX, CNRS/Inria AMIB, Ecole Polytechnique, Palaiseau, France.|ISE-M, Universitxc3xa9 Montpellier, CNRS, IRD, EPHE, Montpellier, France Institut de Biologie Computationnelle (IBC), Montpellier, France.