PHYLOGENETIC ANALYSIS OF 10 BLACK YEAST SPECIES USING NUCLEAR SMALL-SUBUNIT RIBOSOMAL-RNA GENE-SEQUENCES

The nuclear small subunit rRNA genes of authentic strains of the black yeasts Exophiala dermatitidis, Wangiella dermatitidis, Sarcinomyces p haeomuriformis, Capronia mansonii, Nadsoniella nigra var. hesuelica, P haeoannellomyces elegans, Phaeococcomyces exophialae, Exophiala jeanse lmei var. jeanselmei and E. castellanii were amplified by PCR and dire ctly sequenced. A putative secondary structure of the nuclear small su bunit rRNA of Exophiala dermatitidis was predicted from the sequence d ata. Alignment with corresponding sequences from Neurospora crassa and Aureobasidium pullulans was performed and a phylogenetic tree was con structed using the neighbor-joining method. The obtained topology of t he tree was confirmed by bootstrap analysis. Based upon this analysis all fungi studied formed a well-supported monophyletic group clusterin g as a sister group to one group of the Plectomycetes (Trichocomaceae and Onygenales). The analysis confirmed the close relationship postula ted between Exophiala dermatitidis, Wangiella dermatitidis and Sarcino myces phaeomuriformis. This monophyletic clade also contains the teleo morph species Capronia mansonii thus confirming the concept of a teleo morph connection of the genus Exophiala to a member of the Herpotrichi ellaceae. However, Exophiala castellanii did not belong to this clade. Therefore, this species is not the anamorph of Capronia mansonii as i t was postulated.