The identification and phylogenetic relationship of pathogenic species of Aspergillus based on the mitochondrial cytochrome b gene.
To study the identification and phylogeny of pathogenic isolates of Aspergillus, we designed primers from known cytochrome b amino acid sequences. Using these primers, 426 bp fragments of a mitochondrial (mt) cytochrome b gene were amplified by polymerase chain reaction (PCR), directly sequenced, and compared among Aspergillus fumigatus, A. flavus, A. niger, A. terreus and Emericella nidulans. Except for E. nidulans, all strains produced the 426 bp fragment by PCR. The E. nidulans strains demonstrated both an intron-presence fragment ( approximately 1500 bp) and intron-absence fragment (426 bp). Species-specific nucleotides were found in each of the five species. Based on sequence analysis, the strains were further divided into several groups within each species. When a 142-amino-acid sequence was estimated from the 426 bp nucleotide sequence using the yeast mt genetic code, the amino acid sequences showed no difference among strains of the individual species. DNA-based phylogenetic and amino acid-based trees were constructed. In conclusion, the DNA sequences of the cytochrome b gene may be of use in identification of pathogenic Aspergillus species and the amino acid-based tree suitable for discussing their phylogenetic relationships.
Research Center for Pathogenic Fungi and Microbial Toxicoses, Chiba, University, 1-8-1, Inohana, Chou-ku, Chiba 260-8673, Japan.
L
L
Wang
K
K
Yokoyama
M
M
Miyaji
K
K
Nishimura
D000595:Amino Acid Sequence; D001230:Aspergillus / Q000145:classification / Q000235:genetics* / Q000472:pathogenicity; D001231:Aspergillus flavus / Q000235:genetics; D001232:Aspergillus fumigatus / Q000235:genetics; D001234:Aspergillus niger / Q000235:genetics; D001483:Base Sequence; D003573:Cytochrome b Group / Q000235:genetics*; D004271:DNA, Fungal / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics*; D005800:Genes, Fungal; D007438:Introns; D008969:Molecular Sequence Data; D010802:Phylogeny; D010944:Plants / Q000235:genetics; D016133:Polymerase Chain Reaction; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D014774:Virulence
D003573:Cytochrome b Group; D004271:DNA, Fungal; D004272:DNA, Mitochondrial