Identification of species in Aspergillus section Flavi based on sequencing of the mitochondrial cytochrome b gene.
The partial sequences of the mitochondrial (mt) cytochrome b gene (402 bp) were determined for species of Aspergillus section Flavi. On the basis of identities of DNA sequences, 77 strains were divided into seven DNA types, from D-1 to D-7. The type strains of A. sojae, A. parasiticus, A. flavus and A. oryzae together, A. tamarii, and A. nomius were placed in DNA types D-1. D-2, D-4, D-5 and D-7, respectively. These species could be differentiated from each other. Furthermore, two other DNA types, D-3 and D-6 were found. DNA type D-3 was closely related to A. parasiticus (D-2) and included one strain that deposited as A. flatus var. flavus and produced aflatoxins B and G. DNA types D-6 included one strain named A. flavus and closely related to A. tamarii. The observations of conidial wall texture by SEM (Scanning Electron Microscopy) supported the relationships derived from the cytochrome b gene. The production of aflatoxins was also examined. Using the DNA sequence of cytochrome b gene, several strains were reidentified. The derived amino acids sequences were all the same in the studied strains. The mt cytochrome b gene is useful and reliable in distinguishing and identifying the species in Aspergillus section Flavi.
Wang
L
L
Research Center for Pathogenic Fungi and Microbial Toxicoses, Chiba University, Japan.
Yokoyama
K
K
Takahasi
H
H
Kase
N
N
Hanya
Y
Y
Yashiro
K
K
Miyaji
M
M
Nishimura
K
K
D000595:Amino Acid Sequence; D001230:Aspergillus / Q000145:classification* / Q000235:genetics* / Q000648:ultrastructure; D001483:Base Sequence; D003573:Cytochrome b Group / Q000235:genetics*; D004271:DNA, Fungal / Q000235:genetics; D008855:Microscopy, Electron, Scanning; D008928:Mitochondria; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000379:methods
D003573:Cytochrome b Group; D004271:DNA, Fungal