Unfortunately, E-sequence cannot be used directly to date recombination events, as we estimated that the substitution rates for the E-gene is significantly lower than for other viral genes. This means that dates obtained from E-sequences alone tend to be younger and do not represent accurately the temporal dynamic of this viral lineage. We suggest that a large dataset that includes sonly E-sequences could nevertheless be used to date additional divergence events by specifying informative priors on the ages of some important nodes. We describe an incremental analytical strategy that bases these priors on posterior distributions derived from the analysis of full-length coding sequences following removal of the E-sequences.