Cyphellophora is a genus of black yeast-like fungi characterised by having simple phialides with multiseptate,curved conidia.Judging from SSU and LSU data,Cyphellophora was found to be located in a well-supported clad...Cyphellophora is a genus of black yeast-like fungi characterised by having simple phialides with multiseptate,curved conidia.Judging from SSU and LSU data,Cyphellophora was found to be located in a well-supported clade within the Chaetothyriales comprising a number of species occurring on human skin and nail.Cyphellophora is phylogenetically close to Phialophora europaea,P.reptans and P.oxyspora,though morphologically these species produce singlecelled phialoconidia rather than multiseptate ones.Pseudomicrodochium suttonii and P.fusarioides have dark colonies and phylogenetically fit in with Cyphellophora;the type species of Pseudomicrodochium,P.aciculare,has similar,septate conidia but has a hyaline thallus.In the present study,multilocus phylogenetic analyses were combined with morphology and physiology.Sequences of the internal transcribed spacer region,the DNA dependent RNA polymerase II largest subunit and the partial beta tubulin gene were analysed for a set of 30 strains.Two novel species,Cyphellophora pauciseptata and Phialophora ambigua were discovered.Cyphellophora eucalypti was reduced to synonymy of C.guyanensis.The role of the studied fungi between colonization and infection of human skin was discussed.Putative virulence factors for these black yeast-like fungi were hypothesized to be the ability to assimilate monoaromatic hydrocarbons,to produce melanin pigments,and to tolerate the temperature of epidermal human skin.展开更多
To confirm species delimitations in the‘jeanselmeiclade’in the Chaetothyriales,four independent markers were analysed,and phylogenetic trees were reconstructed using different algorithms.Reproductive isolation withi...To confirm species delimitations in the‘jeanselmeiclade’in the Chaetothyriales,four independent markers were analysed,and phylogenetic trees were reconstructed using different algorithms.Reproductive isolation within the complex and reproductive modes in the species involved were determined,in order to explore specific borderlines using Genealogical Concordance Phylogenetic Species Recognition(GCPSR).Sequences of the Internal Transcribed Spacer(ITS),partial Translation Elongation Factor 1-α(TEF1),β-Tubulin(BT2),and Actin(ACT1)genes were analysed for a set of 81 strains.Phylogenetic reconstruction was performed using neighbour-joining(NJ),maximum parsimony(MP),maximum likelihood(ML)and Bayesian analysis(BA)to evaluate the concordance of topologies obtained under different optimization criteria.Incongruence among lineages was detected by Partition Homogeneity Test(PHT).Most Exophiala species analysed in this study seemed to be preponderantly clonal.A group of species around Exophiala spinifera showed a tendency toward human pathogenicity,whereas species around E.bergeri were often associated with environments rich in hydrocarbons.Though the tree topologies were not completely identical when different algorithms were used,the four gene lineages were nearly congruent and the trees of the combined multilocus data set did not provide more phylogenetic information than those of separate data sets.ITS data are sufficient for identification of species in the‘jeanselmei-clade’.展开更多
基金This work was supported by the project 11CPD009 of the china desk of the Netherlands Academy of Sciences.
文摘Cyphellophora is a genus of black yeast-like fungi characterised by having simple phialides with multiseptate,curved conidia.Judging from SSU and LSU data,Cyphellophora was found to be located in a well-supported clade within the Chaetothyriales comprising a number of species occurring on human skin and nail.Cyphellophora is phylogenetically close to Phialophora europaea,P.reptans and P.oxyspora,though morphologically these species produce singlecelled phialoconidia rather than multiseptate ones.Pseudomicrodochium suttonii and P.fusarioides have dark colonies and phylogenetically fit in with Cyphellophora;the type species of Pseudomicrodochium,P.aciculare,has similar,septate conidia but has a hyaline thallus.In the present study,multilocus phylogenetic analyses were combined with morphology and physiology.Sequences of the internal transcribed spacer region,the DNA dependent RNA polymerase II largest subunit and the partial beta tubulin gene were analysed for a set of 30 strains.Two novel species,Cyphellophora pauciseptata and Phialophora ambigua were discovered.Cyphellophora eucalypti was reduced to synonymy of C.guyanensis.The role of the studied fungi between colonization and infection of human skin was discussed.Putative virulence factors for these black yeast-like fungi were hypothesized to be the ability to assimilate monoaromatic hydrocarbons,to produce melanin pigments,and to tolerate the temperature of epidermal human skin.
文摘To confirm species delimitations in the‘jeanselmeiclade’in the Chaetothyriales,four independent markers were analysed,and phylogenetic trees were reconstructed using different algorithms.Reproductive isolation within the complex and reproductive modes in the species involved were determined,in order to explore specific borderlines using Genealogical Concordance Phylogenetic Species Recognition(GCPSR).Sequences of the Internal Transcribed Spacer(ITS),partial Translation Elongation Factor 1-α(TEF1),β-Tubulin(BT2),and Actin(ACT1)genes were analysed for a set of 81 strains.Phylogenetic reconstruction was performed using neighbour-joining(NJ),maximum parsimony(MP),maximum likelihood(ML)and Bayesian analysis(BA)to evaluate the concordance of topologies obtained under different optimization criteria.Incongruence among lineages was detected by Partition Homogeneity Test(PHT).Most Exophiala species analysed in this study seemed to be preponderantly clonal.A group of species around Exophiala spinifera showed a tendency toward human pathogenicity,whereas species around E.bergeri were often associated with environments rich in hydrocarbons.Though the tree topologies were not completely identical when different algorithms were used,the four gene lineages were nearly congruent and the trees of the combined multilocus data set did not provide more phylogenetic information than those of separate data sets.ITS data are sufficient for identification of species in the‘jeanselmei-clade’.
