Enhanced gene targeting frequency in ku70 and ku80 disruption mutants of Aspergillus sojae and Aspergillus oryzae

Mol Genet Genomics. 2006 May;275(5):460-70. doi: 10.1007/s00438-006-0104-1. Epub 2006 Feb 10.


In the koji molds Aspergillus sojae and Aspergillus oryzae, exogenous DNA is integrated in the genome, in most cases irrespective of the sequence homology, suggesting that DNA integration occurs predominantly through a nonhomologous end joining pathway where two ku genes, namely, ku70 and ku80, play a key role. To determine the effect of ku gene disruption on the gene targeting frequency, we constructed ku70-, ku80-, and ku70-ku80-disrupted strains of A. sojae and A. oryzae. The gene targeting frequency of the tannase gene in ku70 and ku80 strains of both Aspergillus species was markedly enhanced as compared with that of the parental strains. The gene targeting frequency of the aflR and ku80 genes was also enhanced in an A. sojae ku70 background. Therefore, the koji mold strains with ku-disrupted genes will be excellent tools as hosts for efficient gene targeting.

Publication types

  • Comparative Study

MeSH terms

  • Antigens, Nuclear / genetics*
  • Aspergillus oryzae / genetics*
  • DNA Repair / physiology
  • DNA-Binding Proteins / genetics*
  • Down-Regulation / physiology
  • Gene Deletion
  • Gene Frequency*
  • Gene Targeting*
  • Genes, Fungal*
  • Ku Autoantigen
  • Point Mutation


  • Antigens, Nuclear
  • DNA-Binding Proteins
  • Ku Autoantigen