A new marker sequence for systematics of medically important fungi based on amino acid sequence of the largest subunit of RNA polymerase I.
Molecular evolution has dominated taxonomic studies for decades, replacing traditional methods for identification and classification. However, there is a need for better markers to resolve the problems that have limited their usefulness. In this report, we introduce the protein tag (Ptag) sequence, a highly polymorphic amino acid sequence within the C-terminal region of the largest subunit of RNA polymerase I, as a new systematic tag sequence for delineating the evolutionary history of medically important fungi. As Ptag sequences are highly polymorphic between species and low within species, 42 fungal species representing the main taxonomic groups in the phyla Ascomycota and Basidiomycota were tested. The phylogenetic tree inferred from the Ptag sequences showed high consistency with the accepted classification of the Assembling the Fungal Tree of Life (AFTOL) project. Moreover, it could resolve the interspecies phylogenetic relationships of the tested taxa. In contrast, the phylogeny inferred from the nucleotide tag (Ntag) sequence, encoding the Ptag peptide, displayed lesser discriminatory power in resolving the phylogenetic relationships among distantly related taxa. In the case of closely related fungal species, the phylogenetic trees for Ptag and Ntag sequences were consistent with the tree for ITS1 sequences of 11 dermatophytic species. Taken together, the Ptag sequences should contribute to inferring phylogeny among species whereas the Ntag sequences should be useful to analyze variations among closely related species to resolve taxonomic issues in fungi.
Laboratory of Space and Environmental Medicine, Graduate School of Medicine, Teikyo University, Tokyo, Japan.
Chiaki
C
Yamanishi
Laboratory of Space and Environmental Medicine, Graduate School of Medicine, Teikyo University, Tokyo, Japan.|General Medical Education and Research Center, Teikyo University, Tokyo, Japan.
Mohamed Mahdi
MM
Alshahni
Animal Sciences, University of the Ryukyus, Okinawa, Japan.
Ayako
A
Sano
Laboratory of Plant Cell Technology, Graduate School of Horticulture, Chiba University, Chiba, Japan.
Ikuo
I
Nakamura
Laboratory of Space and Environmental Medicine, Graduate School of Medicine, Teikyo University, Tokyo, Japan.|General Medical Education and Research Center, Teikyo University, Tokyo, Japan.|Teikyo University Institute of Medical Mycology, Tokyo, Japan.
Koichi
K
Makimura
D000595:Amino Acid Sequence; D001203:Ascomycota / Q000145:classification* / Q000235:genetics*; D001483:Base Sequence; D001487:Basidiomycota / Q000145:classification* / Q000235:genetics*; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D005819:Genetic Markers / Q000235:genetics; D009181:Mycoses / Q000382:microbiology*; D010802:Phylogeny; D012318:RNA Polymerase I / Q000737:chemistry / Q000235:genetics*; D017422:Sequence Analysis, DNA; D013045:Species Specificity
D004271:DNA, Fungal; D005819:Genetic Markers; D012318:RNA Polymerase I
RNA polymerase I; dermatophytes; fungi; molecular marker; phylogenetic tree