An inducible expression system in the alga Nannochloropsis gaditana controlled by the nitrate reductase promoter
An inducible expression system in the alga Nannochloropsis gaditana controlled by the nitrate reductase promoter
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DOI：
10.1007/s10811-018-1510-6
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发表时间：
2019-02-01
影响因子：
3.3
通讯作者：
Bibby, Thomas S.
中科院分区：
文献类型：
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作者：
Jackson, Harry O.;Berepiki, Adokiye;Bibby, Thomas S.
海洋微藻Nannochloropsis gaditana由于其能够产生大量脂质而成为研究藻类衍生生物燃料的模式生物。此外，由于其易于转化和可获得测序和注释的基因组，该物种具有生物技术潜力。以诱导方式控制转基因表达的能力是许多基因工程方法的重要要求，因此，诱导启动子是宿主生物分子工具包的重要组成部分。我们设计了一个表达载体，该表达载体包含内源硝酸还原酶基因上游1.3kb的类似区域，并证明了该表达载体能够促进异源增强型绿色荧光蛋白（eGFP）报告基因的表达。在氨的存在下，eGFP报告基因的表达无法检测到；然而，在硝酸盐的存在下，eGFP的表达被诱导。此外，我们证明了如何改变生长介质的氮源可以用来精确控制表达。我们已经证明硝酸还原酶启动子可以作为一种强大的分子工具在N. gaditana中异种蛋白的表达，进一步促进了该物种作为生物技术候选菌株的发展。
The marine microalgal species Nannochloropsis gaditana has emerged as a model organism for research into algal-derived biofuels due to its ability to produce large amounts of lipids. In addition, this species has biotechnological potential owing to its ease of transformation and availability of a sequenced and annotated genome. The ability to control expression of transgenes in an inducible manner is an important requirement for many genetic engineering approaches and as such, inducible promoters are an important component of the molecular toolkit for a host organism. We designed an expression vector containing a similar to 1.3kb region upstream of the endogenous nitrate reductase gene of N. gaditana and demonstrated this is capable of promoting the expression of a heterologous enhanced green fluorescent protein (eGFP) reporter. In the presence of ammonium, expression of the eGFP reporter was undetectable; however, in the presence of nitrate, eGFP expression is induced. In addition, we demonstrated how altering the nitrogen source of the growth media can be used to precisely control expression. We have shown that the nitrate reductase promoter can be used as a powerful molecular tool for heterologous protein expression in N. gaditana, further contributing to the development of this species as a candidate strain for biotechnology.