The nitrate reductase gene-switch: a system for regulated expression in transformed cells of Dunaliella salina.
The control of promoter activity by nitrogen source has recently emerged as an intriguing system for regulated expression of the heterologous genes. The purpose of this work was to investigate whether heterologous gene expression in transgenic Dunaliella salina would be controlled by an inducible promoter. Here we identify that the nitrate reductase (NR) transcripts of D. salina are induced by nitrate but repressed by ammonium. The bar gene integrated into the genome of D. salina is transcribed by a promoter of the NR gene from D. salina and the bar transcripts are induced by nitrate but repressed by ammonium. PPT-resistance of transformants disappears when they are transferred from nitrate-containing medium to ammonium-containing medium. The findings of this study demonstrate that the promoter of the D. salina NR gene can be used to control expression of the heterologous genes in transgenic D. salina.
Li
Jie
J
Laboratory for Cell Biology, The First Affiliated Hospital, Zhengzhou University, Henan 450052, PR China.
Xue
Lexun
L
Yan
Hongxia
H
Wang
Lili
L
Liu
Lingling
L
Lu
Yumin
Y
Xie
Hua
H
D000613:Aminobutyrates / Q000494:pharmacology; D001483:Base Sequence; D002461:Cell Line, Transformed; D000460:Chlorophyta / Q000166:cytology* / Q000201:enzymology / Q000235:genetics*; D003001:Cloning, Molecular; D018387:Codon, Initiator; D018388:Codon, Terminator; D017931:DNA Primers; D048028:DNA, Algal / Q000737:chemistry / Q000235:genetics; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D016678:Genome; D007700:Kinetics; D008969:Molecular Sequence Data; D009565:Nitrate Reductases / Q000235:genetics*; D009566:Nitrates / Q000494:pharmacology; D021141:Nucleic Acid Amplification Techniques; D010802:Phylogeny; D030821:Plants, Genetically Modified; D010957:Plasmids; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D015183:Restriction Mapping; D017422:Sequence Analysis, DNA; D013056:Spectrophotometry, Ultraviolet
D000613:Aminobutyrates; D018387:Codon, Initiator; D018388:Codon, Terminator; D017931:DNA Primers; D048028:DNA, Algal; D004791:Enzyme Inhibitors; D009566:Nitrates; D000644:Quaternary Ammonium Compounds; D012333:RNA, Messenger; C003121:phosphinothricin; D009565:Nitrate Reductases