Combining Orthology and Xenology Data in a Common Phylogenetic Tree

Resumo


In mathematical phylogenetics, types of events in a gene tree T are formalized by vertex labels t(v) and set-valued edge labels λ(e). The orthology and paralogy relations between genes are a special case of a map δ on the pairs of leaves of T defined by δ(x,y)=q if the last common ancestor lca(x,y) of x and y is labeled by an event type q, e.g., speciation or duplication. Similarly, a map ε with m∈ε(x,y) if m∈λ(e) for at least one edge e along the path from lca(x,y) to y generalizes xenology, i.e., horizontal gene transfer. We show that a pair of maps (δ,ε) derives from a tree (T,t,λ) in this manner if and only if there exists a common refinement of the (unique) least-resolved vertex labeled tree (Tδ,tδ) that explains δ and the (unique) least-resolved edge labeled tree (Tεε) that explains ε (provided both trees exist). This result remains true if certain combinations of labels at incident vertices and edges are forbidden.

Palavras-chave: Mathematical phylogenetics, Rooted trees, Binary relations, Symbolic ultrametric, Fitch map, Consistency

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Publicado
22/11/2021
HELLMUTH, Marc; MICHEL, Mira; NØJGAARD, Nikolai N.; SCHALLER, David; STADLER, Peter F.. Combining Orthology and Xenology Data in a Common Phylogenetic Tree. In: SIMPÓSIO BRASILEIRO DE BIOINFORMÁTICA (BSB), 14. , 2021, Online. Anais [...]. Porto Alegre: Sociedade Brasileira de Computação, 2021 . p. 53-64. ISSN 2316-1248.