Complete mitogenome sequence of Ricasolia amplissima (Lobariaceae) reveals extensive mitochondrial DNA rearrangement within the Peltigerales (lichenized ascomycetes)

Abstract The structure of mitochondrial genomes varies among non-lichenized fungi in terms of their genic and intronic content and genic order. Whether lichenized fungal mitogenomes are equally labile is unknown due to the paucity of available mitogenomes. We assembled the mitogenome of Ricasolia amplissima (Peltigerales, Lobariaceae), using massive parallel sequencing, and compared its structure to that of two species of Peltigera (Peltigeraceae). The mitochondrial genome of R. amplissima comprised 82,333 bp, with a 29.8% G+C content, and holds 15 unique protein-coding genes, 29 tRNA genes, two rRNA genes, and one non-coding RNA gene. Although the protein-coding gene content in the mitogenome of Peltigera and Ricasolia was identical, the relative gene order differed substantially, revealing that significant gene rearrangements also characterize the evolution of mitogenomes of lichenized ascomycetes at a relatively shallow phylogenetic depth, such as within the order Peltigerales.