title: Evaluation of toxicity of the mycotoxin citrinin using yeast ORF DNA microarray and Oligo DNA microarray.
abstract: BACKGROUND
  Mycotoxins are fungal secondary metabolites commonly present in feed and food, and are widely regarded as hazardous contaminants. Citrinin, one of the very well known mycotoxins that was first isolated from Penicillium citrinum, is produced by more than 10 kinds of fungi, and is possibly spread all over the world. However, the information on the action mechanism of the toxin is limited. Thus, we investigated the citrinin-induced genomic response for evaluating its toxicity.
  
  
  RESULTS
  Citrinin inhibited growth of yeast cells at a concentration higher than 100 ppm. We monitored the citrinin-induced mRNA expression profiles in yeast using the ORF DNA microarray and Oligo DNA microarray, and the expression profiles were compared with those of the other stress-inducing agents. Results obtained from both microarray experiments clustered together, but were different from those of the mycotoxin patulin. The oxidative stress response genes--AADs, FLR1, OYE3, GRE2, and MET17--were significantly induced. In the functional category, expression of genes involved in "metabolism", "cell rescue, defense and virulence", and "energy" were significantly activated. In the category of "metabolism", genes involved in the glutathione synthesis pathway were activated, and in the category of "cell rescue, defense and virulence", the ABC transporter genes were induced. To alleviate the induced stress, these cells might pump out the citrinin after modification with glutathione. While, the citrinin treatment did not induce the genes involved in the DNA repair.
  
  
  CONCLUSIONS
  Results from both microarray studies suggest that citrinin treatment induced oxidative stress in yeast cells. The genotoxicity was less severe than the patulin, suggesting that citrinin is less toxic than patulin. The reproducibility of the expression profiles was much better with the Oligo DNA microarray. However, the Oligo DNA microarray did not completely overcome cross hybridization.
authors.affiliation: Human Stress Signal Research Center, National Institute of Industrial Science and Technology, AIST, Tsukuba West, Onogawa Tsukuba, Ibaraki, Japan. hitoshi.iwahashi@aist.go.jp
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Iwahashi
authors.forename: Emiko
authors.initials: E
authors.lastname: Kitagawa
authors.forename: Yoshiteru
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Youji
authors.initials: Y
authors.lastname: Ueda
authors.forename: Yo-hei
authors.initials: YH
authors.lastname: Ishizawa
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Nobumasa
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Kuboki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hosoda
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Iwahashi
mesh_terms: D002953:Citrinin / Q000633:toxicity*; D016000:Cluster Analysis; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects*; D005800:Genes, Fungal; D005978:Glutathione / Q000378:metabolism; D053858:Metabolic Networks and Pathways / Q000187:drug effects / Q000235:genetics; D008715:Methionine / Q000378:metabolism; D008954:Models, Biological; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D009841:Oligonucleotides / Q000032:analysis; D016366:Open Reading Frames; D010365:Patulin / Q000633:toxicity; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000235:genetics; D018675:Toxicity Tests / Q000379:methods*
chemical_list: D009841:Oligonucleotides; D002953:Citrinin; D010365:Patulin; D008715:Methionine; D005978:Glutathione