LBBE - Laboratoire de Biométrie et Biologie Evolutive - UMR 5558, Inria Grenoble - Rhône-Alpes, LIRIS - Laboratoire d'InfoRmatique en Image et Systèmes d'information
3MCB - McGill Centre for Bioinformatics (4th floor, Bellini Building, Life Sciences Complex ; 3649 Promenade Sir William Osler ; Montréal, Québec - Canada)
McGill University (845, rue Sherbrooke O. Montréal (Québec) Canada H3A 0G4 - Canada)
Abstract : Background Reconciled gene trees yield orthology and paralogy relationships between genes. This information may however contradict other information on orthology and paralogy provided by other footprints of evolution, such as conserved synteny. Results We explore a way to include external information on orthology in the process of gene tree construction. Given an initial gene tree and a set of orthology constraints on pairs of genes or on clades, we give polynomial-time algorithms for producing a modified gene tree satisfying the set of constraints, that is as close as possible to the original one according to the Robinson-Foulds distance. We assess the validity of the modifications we propose by computing the likelihood ratio between initial and modified trees according to sequence alignments on Ensembl trees, showing that often the two trees are statistically equivalent. Availability Software and data available upon request to the corresponding author.
