Isolation and characterization of a novel DNA segment that enables the plasmids to replicate autonomously in Aspergillus nidulans

Aspergillus nidulans에서 플라스미드의 자가복제를 유발하는 DNA절편의 분리 및 분석

  • Kim, Jin-Hee (Wonkwang Institute of Biotechnology, Wonkwang University) ;
  • Han, Kyu-Yong (Dept. of Molecular Biology, Wonkwang University) ;
  • Han, Kap-Hoon (Dept. of Molecular Biology, Wonkwang University) ;
  • Han, Dong-Min (Wonkwang Institute of Biotechnology, Wonkwang University)
  • 김진희 (원광대학교 생명공학연구소) ;
  • 한규용 (원광대학교 자연과학대학 분자생물학과) ;
  • 한갑훈 (원광대학교 자연과학대학 분자생물학과) ;
  • 한동민 (원광대학교 생명공학연구소)
  • Received : 1997.03.18
  • Accepted : 1998.06.23
  • Published : 1998.09.01

Abstract

A plasmid pNPG contains a genomic DNA complementing npgA1 which is located on the left arm of linkage group I. It transformed Aspergillus nidulans at a high frequency. No abortive transformants were observed and the $Trp^+$ transformants were all $Npg^+$. The 10.4 kb Psti fragment of the genomic DNA was subcloned into pILJ16, which increased the transformation efficiency by more than 200-folds. The transformants were mitotically unstable and yielded $Arg^-$ conidia at the frequency of more than 80%. An additional gene cloned into the plasmid containing the fragment was always lost with $argB^+$ marker. These characteristics strongly indicate the possibility that the plasmids autonomously replicate. The full activity of enhanced transformation was retained on the 4.9 kb EcoRI-HaeIII fragment. The DNA segment was similar to AMA1 rather than ANS1 in function and designated AMA2.

Keywords

Aspergillus nidulans;autonomously replicating plasmid;transformation

Acknowledgement

Supported by : 한국학술진흥재단