Recent dermatophyte divergence revealed by comparative and phylogenetic analysis of mitochondrial genomes

Abstract

Background: Dermatophytes are fungi that cause superficial infections of the skin, hair, and nails. They are the most common agents of fungal infections worldwide. Dermatophytic fungi constitute three genera, Trichophyton, Epidermophyton, and Microsporum, and the evolutionary relationships between these genera are epidemiologically important. Mitochondria are considered to be of monophyletic origin and mitochondrial sequences offer many advantages for phylogenetic studies. However, only one complete dermatophyte mitochondrial genome (E. floccosum) has previously been determined.

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

“…Nectriaceae) within Ascomycetes. Collectively, the Fusarium species are most closely related to other members of the order Hypocreales, which is consistent with previous studies carried out using complete sets of mt proteins or nucleotides (Pantou et al, 2008;Wu et al, 2009;Lee and Young, 2009). Within the Nectriaceae, the relationship between the four Fusarium species is the same as those obtained with nuclear markers , with F. verticillioides being most closely related to F. oxysporum and F. solani being distantly related to the other species.…”

“…Nectriaceae) that is most closely related to the other members of the order Hypocreales. The topology is the same as those previously reported that used concatenated mitochondrial amino acid sequences and/or nucleotides (Kouvelis et al, 2004;Pantou et al, 2006;Wu et al, 2009) and the relationship between the four Fusarium species is consistent with that obtained using nuclear DNA markers .…”

“…Among species in the fungal subphylum Pezizomycotina, intragenic comparative studies of mtDNAs conducted in members of the class Dothideomycete (Torriani et al, 2008) and Eurotiomycete (Juhász et al, 2008;Wu et al, 2009), show expected similarities. In contrast, large differences in the size of mtDNAs have been reported in intragenic comparisons within members of the subphylum Saccharomycotina [in Candida sp.…”

“…Variation in mitochondrial sequences has long been used to characterize fungi (Bruns and Gardes, 1993) and has proven to be valuable for phylogenetic studies due to an accelerated rate of mutation compared to nuclear DNAs (Bruns and Szaro, 1992) along with diversity in gene order and in non-coding regions (Pantou et al, 2006). The analysis of complete mitochondrial genomes has been effective in establishing phylogenetic relationships in many fungal genera (Bullerwell et al, 2003;Kouvelis et al, 2004;Pantou et al, 2006Pantou et al, , 2008Ghikas et al, 2006;Kosa et al, 2006;Wu et al, 2009;Lee and Young, 2009), with the evolutionary relationships typically being concordant with those based on nuclear loci (Berbee and Taylor, 2001;Sommerhalder et al, 2007).…”

The Spectrum of Fungi That Infects Humans

“…Recent analysis of mitochondrial genomes of six dermatophytes comprising the three morphologically defined anamorphic genera, Trichophyton, Microsporum, and Epidermophyton, together with 29 other members of Ascomycota, confirmed that the dermatophytes are descended from a common ancestor (are monophyletic) and separated from other fungi only 32 -50 million years ago (Wu et al 2009). This study also found that classification of species by molecular characters frequently contradicted the traditional classifications based on morphologic traits (Wu et al 2009), emphasizing the fact that fungal morphology is enormously flexible and convergent evolution is common, so that only limited predictions of their physiology can be made from the appearance of fungal structures. In contrast, molecular phylogenetic studies have confirmed the grouping of dermatophytes by their ecologic and clinical features, including the distinct sites of the human body they tend to infect (Cafarchia et al 2013).…”