New tools for chloroplast genetic engineering allow the synthesis of human growth hormone in the green alga Chlamydomonas reinhardtii
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Published version
Author(s)
Wannathong, Thanyanan
Waterhouse, Janet C
Young, Rosanna EB
Economou, Chloe K
Purton, Saul
Type
Journal Article
Abstract
In recent years, there has been an increasing interest in the exploitation of microalgae in industrial biotechnology. Potentially, these phototrophic eukaryotes could be used for the low-cost synthesis of valuable recombinant products such as bioactive metabolites and therapeutic proteins. The algal chloroplast in particular represents an attractive target for such genetic engineering, both because it houses major metabolic pathways and because foreign genes can be targeted to specific loci within the chloroplast genome, resulting in high-level, stable expression. However, routine methods for chloroplast genetic engineering are currently available only for one species—Chlamydomonas reinhardtii—and even here, there are limitations to the existing technology, including the need for an expensive biolistic device for DNA delivery, the lack of robust expression vectors, and the undesirable use of antibiotic resistance markers. Here, we describe a new strain and vectors for targeted insertion of transgenes into a neutral chloroplast locus that (i) allow scar-less fusion of a transgenic coding sequence to the promoter/5′UTR element of the highly expressed endogenous genes psaA or atpA, (ii) employ the endogenous gene psbH as an effective but benign selectable marker, and (iii) ensure the successful integration of the transgene construct in all transformant lines. Transformation is achieved by a simple and cheap method of agitation of a DNA/cell suspension with glass beads, with selection based on the phototrophic rescue of a cell wall-deficient ΔpsbH strain. We demonstrate the utility of these tools in the creation of a transgenic line that produces high levels of functional human growth hormone.
Date Issued
2016-02-18
Date Acceptance
2016-01-23
Citation
Applied Microbiology and Biotechnology, 2016, 100 (12), pp.5467-5477
ISSN
0175-7598
Publisher
Springer Verlag
Start Page
5467
End Page
5477
Journal / Book Title
Applied Microbiology and Biotechnology
Volume
100
Issue
12
Copyright Statement
© The Author(s) 2016. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000376456700022&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Subjects
Science & Technology
Life Sciences & Biomedicine
Biotechnology & Applied Microbiology
Chlamydomonas
Chloroplast
Genetic engineering
Human growth hormone
SELECTABLE MARKER
INDUSTRIAL BIOTECHNOLOGY
RECOMBINANT PROTEINS
PSAA GENE
EXPRESSION
TRANSFORMATION
MICROALGAE
MUTANT
TRANSLATION
PROSPECTS
Publication Status
Published