PT - JOURNAL ARTICLE AU - Nicola F. Müller AU - Ugnė Stolz AU - Gytis Dudas AU - Tanja Stadler AU - Timothy G. Vaughan TI - Bayesian inference of reassortment networks reveals fitness benefits of reassortment in human influenza viruses AID - 10.1101/726042 DP - 2019 Jan 01 TA - bioRxiv PG - 726042 4099 - http://biorxiv.org/content/early/2019/08/06/726042.short 4100 - http://biorxiv.org/content/early/2019/08/06/726042.full AB - Reassortment is an important source of genetic diversity in segmented viruses and is the main source of novel pathogenic influenza viruses. Despite this, studying the reassortment process has been constrained by the lack of a coherent, model-based inference framework. We here introduce a novel coalescent based model that allows us to explicitly model the joint coalescent and reassortment process. In order to perform inference under this model, we present an efficient Markov chain Monte Carlo algorithm to sample rooted networks and the embedding of phylogenetic trees within networks. Together, these provide the means to jointly infer coalescent and reassortment rates with the reassortment network and the embedding of segments in that network from full genome sequence data. Studying reassortment patterns of different human influenza datasets, we find large differences in reassortment rates across different human influenza viruses. Additionally, we find that reassortment events predominantly occur on selectively fitter parts of reassortment networks showing that on a population level, reassortment positively contributes to the fitness of human influenza viruses.