A new inducible expression  system in a transformed green alga, Chlorella vulgaris.
Genetic  transformation is useful for basic research and applied biotechnology. However,  genetic transformation of microalgae is usually quite difficult due to the  technical limitations of existing methods. We cloned the promoter and  terminator of the nitrate reductase gene from the microalga Phaeodactylum  tricornutum and used them for optimization of a transformation system of  the microalga Chlorella vulgaris. This species has been used for food  production and is a promising candidate as a bioreactor for large-scale  production of value-added proteins. A construct was made containing the CAT (chloramphenicol  acetyltransferase) reporter gene driven by the nitrate reductase promoter. This  construct was transferred into the C. vulgaris genome by  electroporation. Expression of CAT in transgenic Chlorella conferred  resistance to the antibiotic chloramphenicol and enabled growth in selective  media. Overall efficiency for the transformation was estimated to be  approximately 0.03%, which is relatively high compared with other available Chlorella transformation systems. Expression of CAT was induced in the  presence of nitrate and inhibited in the presence of ammonium as a sole  nitrogen source. This study presented an inducible recombinant gene expression  system, also providing more gene regulation elements with potential for  biotechnological applications.
Key Laboratory of Aquatic Eutrophication and Control of Harmful Algal Blooms, Guangdong Higher Education Institute, Jinan University, Guangzhou, China.
Y F
YF
Niu
M H
MH
Zhang
W H
WH
Xie
J N
JN
Li
Y F
YF
Gao
W D
WD
Yang
J S
JS
Liu
H Y
HY
Li
D002701:Chloramphenicol / Q000494:pharmacology; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics; D002702:Chloramphenicol Resistance / Q000235:genetics; D048408:Chlorella vulgaris / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D015870:Gene Expression / Q000187:drug effects; D005822:Genetic Vectors / Q000235:genetics; D050901:Nitrate Reductase / Q000235:genetics; D009566:Nitrates / Q000494:pharmacology; D030781:Organisms, Genetically Modified; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic / Q000235:genetics; D012641:Selection, Genetic; D014170:Transformation, Genetic / Q000187:drug effects
D009566:Nitrates; D002701:Chloramphenicol; D050901:Nitrate Reductase; D015500:Chloramphenicol O-Acetyltransferase