It is a circular-mapping DNA molecule of 28 601 bp with a low GC content of 25%. It contains MLN8237 order the usual set of mitochondrial protein and RNA genes characteristic of the majority of sequenced filamentous fungi mitochondrial genomes (Table S1). RNA-encoding genes include 27 tRNA genes and genes for large and small ribosomal RNA (rnS, rnL), as well as a predicted rnpB gene encoding the subunit of mitochondrial RNase P (mtP-RNA), known to be responsible for tRNA processing (Seif et al., 2003). Protein-encoding genes include those for ATP-synthase subunits 6, 8 and 9 (atp6, atp8 and atp9), subunits of cytochrome oxidase (cox1, cox2 and cox3), apocytochrome b (cob), one ribosomal protein

(rps5) and NADH dehydrogenase subunits (nad1, nad2, nad3, nad4, nad4L, nad5 and nad6). Group I or group II introns, frequently interrupting yeast and filamentous fungi mitochondrial genes (Lang et al., 2007), are not found. Two open reading frames (ORFs) located between cox2 and tRNA-R, and between tRNA-H and atp9 could encode for hypothetical proteins without apparent homology to any known proteins in the

GenBank database. All genes are located on one strand and apparently GS-1101 cell line transcribed in one direction (Fig. 1). To extend our analysis of mitochondrial genome organization to other members of the Penicillium/Aspergillus clade, we included mitochondrial genomes that have already been sequenced in whole genome sequencing programs, such as the mitochondrial genomes of P. chrysogenum, A. terreus and A. oryzae. These genomes are available from GenBank as partially annotated or unannotated

contigs. The general features of all compared genomes are summarized in Table 1. It is evident that all compared Penicillium and Aspergillus species possess conserved features of mitochondrial genome organization, including gene content. Genome size variation is low and is explained by the length of intergenic regions and the presence of one intron in the A. oryzae and P. digitatum mitochondrial genomes. The majority of P. solitum mitochondrial tRNA genes are organized into two dense gene clusters, a feature common to many sequenced mitochondrial genomes of filamentous fungi. This DAPT mw set of 27 tRNA genes is sufficient to decode all codons present in the predicted ORFs, alleviating the need for tRNA import into the mitochondria from the cytoplasm (Kolesnikova et al., 2000), as is the case for some yeast, plant and protist mitochondrial genomes. The presence of tRNA-W (anticodon UCA) recognizing the TGA codon, as well as the TGG codon, and the absence of abnormal tRNA-T (anticodon CUN) indicate that P. solitum mitochondrial protein-encoding genes are translated according to genetic code 4 (Fox, 1987), as shown for other Pezizomycotina mitochondrial genomes. All protein-encoding sequences start with the ATG codon, except cox1, which starts with the codon TTG.