Complete mitochondrial genome sequence of the yeast Pichia farinosa and comparative analysis of closely related species

Abstract

Yeasts of the Pichia genus have been isolated from different natural environments. Phylogenies based on multigene sequence analysis have shown that the genus is polyphyletic. Some species of this genus are member of the CTG group. In order to have a better insight into the relationship among species assigned to the yeast genera Pichia into the CTG group, we first sequenced the mitochondrial genome of the osmotolerant yeast Pichia farinosa. We then compared this genome with mitochondrial genomes of yeasts of the CTG group. The P. farinosa mitochondrial DNA is a circular-mapping genome of 32,065 bp, which contains 43 genes transcribed from both strands. It contains a complete set of tRNAs, the small and the large rRNAs, as well as 14 protein-coding genes. Yeasts of the CTG group contain the same core of mitochondrial genes. Phylogenetic analysis based on mitochondrial sequences clearly shows that the CTG group is divided into two distinct clades: the first one contains diploid Candida species, whereas the second mainly contains haploid Pichia species. Moreover, this analysis provides clear evidence that Pichia farinosa and Pichia sorbitophila, which were known to be unique species, are two distinct species.

Reconstructing the Fungal Tree of Life Using Phylogenomics and a Preliminary Investigation of the Distribution of Yeast Prion-Like Proteins in the Fungal Kingdom

“…The SG supertree and BSP infer a sister group relationship between D. hansenii and C. guilliermondii (Figs. 1 and 3) in agreement with previous phylogenetic analysis derived from concatenated mitochondrial proteins (Jung et al 2010). Conversely, the SMG phylogeny infers a sister group relationship between D. hansenii and P. stipitis in agreement with previous phylogenomic (Fitzpatrick et al 2010;Jeffries et al 2007) and phylogenetic studies (Suh et al 2006).…”

Comparative analysis of Fusarium mitochondrial genomes reveals a highly variable region that encodes an exceptionally large open reading frame

“…Previous comparisons of mitochondrial intron distribution among fungal species within particular genera revealed diversity (Bullerwell et al, 2003;Kosa et al, 2006;Juhász et al, 2008;Wu et al, 2009;Jung et al, 2010), but not at the scale detected in our study. It is unclear at this stage whether differences in the distribution of mitochondrial group I introns in Fusarium species is unique to the genus or whether it reflects insufficient sampling of mitochondrial genomes in other genera.…”

High-quality genome sequence of Pichia pastoris CBS7435

“…This is the most closely related yeast strain for which the mitochondrial genome sequence is available according to a recent publication by Dujon (2010). 35.7 kbp is in the range of species related to P. pastoris CBS7435 such as P. farinosa (32 kbp), Pichia stipitis (31 kbp) and Pichia sorbitophila (39 kbp) (Jung et al, 2009;Jung et al, 2010). Interestingly, the G + C content of P. pastoris mitochondrial DNA is equal to Y. lipolytica (22%).…”

“…All genes are encoded on the same strand. Remarkably, the P. pastoris CBS7435 mitochondrial genome encodes the ribosomal protein Var1p, which is absent in all yeast species of the CTG group (Jung et al, 2010). A homolog of the RNA subunit of the mitochondrial RNAseP (RPM1), which is present in Saccharomyces sp.…”