Sul l'inversion des morphisms d'arbres

Assessing the performance of single-copy orthologs for recovering robust fungal phylogenies. Fungal phylogenies involving non-model species are based on a few genes, mostly chosen using historical or practical criteria. Because gene trees are sometimes incongruent with species trees, the resulting phylogenies may not accurately reflect the evolutionary relationships among species. The increase in fungal genome sequences now provides large numbers of genes that could be used for building phylogenies. However, for practical reasons only a few genes can be sequenced in a wide range of species. Here, we asked how many and which genes, among the single-copy genes common to most fungal genomes, were required to recover an accurate and well-supported phylogeny. An automated procedure was developed to extract single-copy orthologous genes from complete fungal genomes using a Markov Clustering Algorithm (MCL-Tribe). After the analysis of 21 complete, publicly available fungal genomes reliably annotated, 246 single-copy orthologous gene clusters were identified. A website called FunyBase is available with open access to the clusters of orthologous sequences. We then inferred maximum likelihood gene trees using the individual aligned orthologous sequences and constructed a reference tree from the concatenated alignments. The same topology as the reference tree was recovered for two genes, individually, that together provided high bootstrap values. The performance of individual genes was highly variable. Both gene size and the total number of variable * Correspondance et tirés à part : Tatiana.Giraud@u-psud.fr