The mitochondrial genome sequence of the arbuscular mycorrhizal fungus Glomus intraradices isolate 494 and implications for the phylogenetic placement of Glomus

摘要

We have determined the complete mitochondrial genome sequence of an isolate of Glomus intraradices, a widespread and well-studied species of arbuscular mycorrhizal fungus. The total genomic DNA of 24 spores from an in vitro root organ culture of the Swiss isolate G. intraradices 494 was amplified by multiple displacement and sequenced using the Roche 454 FLX platform. Contigs were joined by PCR and Sanger sequencing. The circular genome map of 70 606 bp has a G + C content of 37.2%. All the standard fungal mitochondrial genes are present and encoded on the same strand. There are 26 introns and five complete LAGLIDADG homing endonuclease genes. There is no evidence of substantial sequence variation. A well-supported phylogeny based on 14 mitochondrially encoded proteins indicates that the Glomeromycota are not the sister group of the Dikarya.