title: Mitochondrial introgression suggests extensive ancestral hybridization events among Saccharomyces species.
abstract: Horizontal gene transfer (HGT) in eukaryotic plastids and mitochondrial genomes is common, and plays an important role in organism evolution. In yeasts, recent mitochondrial HGT has been suggested between S. cerevisiae and S. paradoxus. However, few strains have been explored given the lack of accurate mitochondrial genome annotations. Mitochondrial genome sequences are important to understand how frequent these introgressions occur, and their role in cytonuclear incompatibilities and fitness. Indeed, most of the Bateson-Dobzhansky-Muller genetic incompatibilities described in yeasts are driven by cytonuclear incompatibilities. We herein explored the mitochondrial inheritance of several worldwide distributed wild Saccharomyces species and their hybrids isolated from different sources and geographic origins. We demonstrated the existence of several recombination points in mitochondrial region COX2-ORF1, likely mediated by either the activity of the protein encoded by the ORF1 (F-SceIII) gene, a free-standing homing endonuclease, or mostly facilitated by A+T tandem repeats and regions of integration of GC clusters. These introgressions were shown to occur among strains of the same species and among strains of different species, which suggests a complex model of Saccharomyces evolution that involves several ancestral hybridization events in wild environments.
authors.affiliation: "Cavanilles" Institute of Biodiversity and Evolution, University of Valencia, Valencia, Spain. Electronic address: david.perisnavarro@wisc.edu.
authors.forename: David
authors.initials: D
authors.lastname: Peris
authors.affiliation: "Cavanilles" Institute of Biodiversity and Evolution, University of Valencia, Valencia, Spain.
authors.forename: Armando
authors.initials: A
authors.lastname: Arias
authors.affiliation: "Cavanilles" Institute of Biodiversity and Evolution, University of Valencia, Valencia, Spain.
authors.forename: Sandi
authors.initials: S
authors.lastname: Orlić
authors.affiliation: Department of Food Biotechnology, Institute of Agrochemistry and Food Technology (IATA), CSIC, Valencia, Spain.
authors.forename: Carmela
authors.initials: C
authors.lastname: Belloch
authors.affiliation: Department of Food Biotechnology, Institute of Agrochemistry and Food Technology (IATA), CSIC, Valencia, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Pérez-Través
authors.affiliation: Department of Food Biotechnology, Institute of Agrochemistry and Food Technology (IATA), CSIC, Valencia, Spain.
authors.forename: Amparo
authors.initials: A
authors.lastname: Querol
authors.affiliation: "Cavanilles" Institute of Biodiversity and Evolution, University of Valencia, Valencia, Spain; Department of Food Biotechnology, Institute of Agrochemistry and Food Technology (IATA), CSIC, Valencia, Spain; Department of Genetics, University of Valencia, Valencia, Spain.
authors.forename: Eladio
authors.initials: E
authors.lastname: Barrio
mesh_terms: D001483:Base Sequence; D003576:Electron Transport Complex IV / Q000235:genetics; D054629:Genome, Mitochondrial; D005843:Geography; D006239:Haplotypes / Q000235:genetics; D006824:Hybridization, Genetic; D008928:Mitochondria / Q000235:genetics*; D016366:Open Reading Frames / Q000235:genetics; D010802:Phylogeny; D012440:Saccharomyces / Q000235:genetics*; D016415:Sequence Alignment; D013045:Species Specificity
chemical_list: D003576:Electron Transport Complex IV
keywords: Interspecies hybridization; Mitochondrial introgression; Recombination; Reticulate evolution; Saccharomyces; Selfish elements