Wide distribution of mitochondrial genome rearrangements in wild strains of the cultivated basidiomycete Agrocybe aegerita

• Published in: Applied and Environmental Microbiology Vol. 61; no. 4; pp. 1187 - 1193
• Main Authors: Barroso, G. (Universite de Bordeaux II Institut National de la Recherche Agronomique, Villenave d'Ornon, France.), Blesa, S, Labarere, J.L
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for Microbiology 01-04-1995
• Subjects: ADN; AGROCYBE; Agrocybe aegerita; Biological and medical sciences; Biology; Classical genetics, quantitative genetics, hybrids; Deoxyribonucleic acid; DIFERENCIAS BIOLOGICAS; DIFFERENCE BIOLOGIQUE; DNA; Ecology, environment; EUROPA OCCIDENTAL; EUROPE OCCIDENTALE; Fundamental and applied biological sciences. Psychology; Fungi; GENETICA MITOCONDRIAL; Genetics; Genetics of eukaryotes. Biological and molecular evolution; GENETIQUE MITOCHONDRIALE; GENOTIPOS; GENOTYPE; Life Sciences; MITOCHONDRIE; MITOCONDRIA; MUTACION; MUTATION; POLIMORFISMO; POLYMORPHISME; Thallophyta, bryophyta; Vegetals; Fungi; Restriction fragment length polymorphism; Gene rearrangement; Deletion; Basidiomycetes; Mitochondrial DNA; Mutation; Genome; Thallophyta; GENETIQUE; BIOLOGIE MOLECULAIRE
• ISSN: 0099-2240; 1098-5336
• DOI: 10.1128/aem.61.4.1187-1193.1995

We used restriction fragment length polymorphisms to examine mitochondrial genome rearrangements in 36 wild strains of the cultivated basidiomycete Agrocybe aegerita, collected from widely distributed locations in Europe. We identified two polymorphic regions within the mitochondrial DNA which varied independently one carrying the Cox II coding sequence and the other carrying the Cox I, ATP6, and ATP8 coding sequences. Two types of mutations were responsible for the restriction fragment length polymorphisms that we observed and, accordingly, were involved in the A. aegerita mitochondrial genome evolution: (i) point mutations, which resulted in strain-specific mitochondrial markers, and (ii) length mutations due to genome rearrangements, such as deletions, insertions, or duplications. Within each polymorphic region, the length differences defined only two mitochondrial types, suggesting that these length mutations were not randomly generated but resulted from a precise rearrangement mechanism. For each of the two polymorphic regions, the two molecular types were distributed among the 36 strains without obvious correlation with their geographic origin. On the basis of these two polymorphisms, it is possible to define four mitochondrial haplotypes. The four mitochondrial haplotypes could be the result of intermolecular recombination between allelic forms present in the population long enough to reach linkage equilibrium. All of the 36 dikaryotic strains contained only a single mitochondrial type, confirming the previously described mitochondrial sorting out after cytoplasmic mixing in basidiomycetes