Colloque

Inférence et validation de transferts horizontaux de gènes

Vladimir Makarenkov

Membre a labase

Vladimir Makarenkov

Résumé du colloque

Horizontal gene transfer (HGT) is one of the main mechanisms driving the evolution of microorganisms. We will present a new polynomial-time algorithm for inferring HGT events and compare three existing and one new tree comparison indices in the context of HGT identification. The proposed algorithm can rely on different optimization criteria, including least-squares (LS), Robinson and Foulds (RF) distance, quartet distance (QD) and bipartition dissimilarity (BD), while searching for an optimal scenario of SPR (Subtree Prune and Regraft) moves needed to transform the given species tree into the given gene tree. We will show that the BD-based algorithm is more accurate and fast than a well-know polynomial time heuristic RIATA-HGT. Moreover, the HGT recovery results yielded by it were generally equivalent to those provided by the exponential-time algorithm LatTrans, but a clear gain in running time was obtained using the new algorithm. Finally, a statistical framework for assessing the reliability of obtained HGTs by bootstrap analysis will be also presented.