title: Mitochondrial genome evolution in species belonging to the Phialocephala fortinii s.l. - Acephala applanata species complex.
abstract: BACKGROUND
  Mitochondrial (mt) markers are successfully applied in evolutionary biology and systematics because mt genomes often evolve faster than the nuclear genomes. In addition, they allow robust phylogenetic analysis based on conserved proteins of the oxidative phosphorylation system. In the present study we sequenced and annotated the complete mt genome of P. subalpina, a member of the Phialocephala fortinii s.l. - Acephala applanata species complex (PAC). PAC belongs to the Helotiales, which is one of the most diverse groups of ascomycetes including more than 2,000 species. The gene order was compared to deduce the mt genome evolution in the Pezizomycotina. Genetic variation in coding and intergenic regions of the mtDNA was studied for PAC to assess the usefulness of mt DNA for species diagnosis.
  
  
  RESULTS
  The mt genome of P. subalpina is 43,742 bp long and codes for 14 mt genes associated with the oxidative phosphorylation. In addition, a GIY-YIG endonuclease, the ribosomal protein S3 (Rps3) and a putative N-acetyl-transferase were recognized. A complete set of tRNA genes as well as the large and small rRNA genes but no introns were found. All protein-coding genes were confirmed by EST sequences. The gene order in P. subalpina deviated from the gene order in Sclerotinia sclerotiorum, the only other helotialean species with a fully sequenced and annotated mt genome. Gene order analysis within Pezizomycotina suggests that the evolution of gene orders is mostly driven by transpositions. Furthermore, sequence diversity in coding and non-coding mtDNA regions in seven additional PAC species was pronounced and allowed for unequivocal species diagnosis in PAC.
  
  
  CONCLUSIONS
  The combination of non-interrupted ORFs and EST sequences resulted in a high quality annotation of the mt genome of P. subalpina, which can be used as a reference for the annotation of other mt genomes in the Helotiales. In addition, our analyses show that mtDNA loci will be the marker of choice for future analysis of PAC communities.
authors.affiliation: Forest Pathology and Dendrology, Institute of Integrative Biology, ETH Zurich, CH-8092, Zurich, Switzerland.
authors.forename: Angelo
authors.initials: A
authors.lastname: Duò
authors.forename: Rémy
authors.initials: R
authors.lastname: Bruggmann
authors.forename: Stefan
authors.initials: S
authors.lastname: Zoller
authors.forename: Matthias
authors.initials: M
authors.lastname: Bernt
authors.forename: Christoph R
authors.initials: CR
authors.lastname: Grünig
mesh_terms: D001203:Ascomycota / Q000235:genetics*; D017124:Conserved Sequence / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics; D019143:Evolution, Molecular; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics; D020440:Gene Duplication / Q000235:genetics; D023061:Gene Order / Q000235:genetics; D015321:Gene Rearrangement / Q000235:genetics; D056426:Genetic Loci / Q000235:genetics; D005819:Genetic Markers; D016681:Genome, Fungal / Q000235:genetics*; D054629:Genome, Mitochondrial / Q000235:genetics*; D016366:Open Reading Frames / Q000235:genetics; D010802:Phylogeny; D011110:Polymorphism, Genetic; D016415:Sequence Alignment; D013045:Species Specificity; D059467:Transcriptome / Q000235:genetics
chemical_list: D004272:DNA, Mitochondrial; D005656:Fungal Proteins; D005819:Genetic Markers