title: Evaluation of genetic markers for identifying isolates of the species of the genus Fusarium.
abstract: BACKGROUND
  Members of the genus Fusarium are well known as one of the most important plant pathogens causing food spoilage and loss worldwide. Moreover, they are associated with human and animal diseases through contaminated foods because they produce mycotoxins. To control fungal hazards of plants, animals and humans, there is a need for a rapid, easy and accurate identification system of Fusarium isolates with molecular methods.
  
  
  RESULTS
  To specify genes appropriate for identifying isolates of various Fusarium species, we sequenced the 18S rRNA gene (rDNA), internal transcribed spacer region 1, 5.8S rDNA, 28S rDNA, β-tubulin gene (β-tub), and aminoadipate reductase gene (lys2), and subsequently calculated the nucleotide sequence homology with pair-wise comparison of all tested strains and inferred the ratio of the nucleotide substitution rates of each gene. Inter-species nucleotide sequence homology of β-tub and lys2 ranged from 83.5 to 99.4% and 56.5 to 99.0%, respectively. The result indicated that sequence homologies of these genes against reference sequences in a database have a high possibility of identifying unknown Fusarium isolates when it is more than 99.0%, because these genes had no inter-species pair-wise combinations that had 100% homologies. Other markers often showed 100% homology in inter-species pair-wise combinations. The nucleotide substitution rate of lys2 was the highest among the six genes.
  
  
  CONCLUSIONS
  The lys2 is the most appropriate genetic marker with high resolution for identifying isolates of the genus Fusarium among the six genes we examined in this study.
authors: Division of Microbiology, National Institute of Health Sciences, Tokyo, Japan. mwatanabe@nihs.go.jp
authors: Maiko
authors: M
authors: Watanabe
authors: Takahiro
authors: T
authors: Yonezawa
authors: Ken-ichi
authors: K
authors: Lee
authors: Susumu
authors: S
authors: Kumagai
authors: Yoshiko
authors: Y
authors: Sugita-Konishi
authors: Keiichi
authors: K
authors: Goto
authors: Yukiko
authors: Y
authors: Hara-Kudo
mesh_terms: D005516:Food Microbiology; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D005670:Fusarium / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D005819:Genetic Markers; D050647:L-Aminoadipate-Semialdehyde Dehydrogenase / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D058889:Molecular Typing; D016533:Mycological Typing Techniques; D012689:Sequence Homology, Nucleic Acid
chemical_list: D005656:Fungal Proteins; D005819:Genetic Markers; D050647:L-Aminoadipate-Semialdehyde Dehydrogenase