Mitochondrial genome variability within the Candida parapsilosis species complex.

Candida parapsilosis species complex includes three closely related species, namely C. parapsilosis (sensu stricto), C. orthopsilosis, and C. metapsilosis. Unlike most other yeast lineages, members of this species complex possess a linear mitochondrial genome. Yet, its circularized mutant form was identified in strains of C. orthopsilosis and C. metapsilosis. To investigate the underlying variability, we performed comparative analyses of the complete mitochondrial DNA sequences in a collection of strains. Our results demonstrate that in contrast to C. parapsilosis and C. metapsilosis, C. orthopsilosis exhibits remarkably high nucleotide diversity whose pattern is consistent with intraspecific genetic exchange.