1
|
Lambert L, de Carpentier F, André P, Marchand CH, Danon A. Type II metacaspase mediates light-dependent programmed cell death in Chlamydomonas reinhardtii. PLANT PHYSIOLOGY 2024; 194:2648-2662. [PMID: 37971939 PMCID: PMC10980519 DOI: 10.1093/plphys/kiad618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 10/12/2023] [Accepted: 10/22/2023] [Indexed: 11/19/2023]
Abstract
Among the crucial processes that preside over the destiny of cells from any type of organism are those involving their self-destruction. This process is well characterized and conceptually logical to understand in multicellular organisms; however, the levels of knowledge and comprehension of its existence are still quite enigmatic in unicellular organisms. We use Chlamydomonas (Chlamydomonas reinhardtii) to lay the foundation for understanding the mechanisms of programmed cell death (PCD) in a unicellular photosynthetic organism. In this paper, we show that while PCD induces the death of a proportion of cells, it allows the survival of the remaining population. A quantitative proteomic analysis aiming at unveiling the proteome of PCD in Chlamydomonas allowed us to identify key proteins that led to the discovery of essential mechanisms. We show that in Chlamydomonas, PCD relies on the light dependence of a photosynthetic organism to generate reactive oxygen species and induce cell death. Finally, we obtained and characterized mutants for the 2 metacaspase genes in Chlamydomonas and showed that a type II metacaspase is essential for PCD execution.
Collapse
Affiliation(s)
- Lou Lambert
- Institut de Biologie Paris Seine, UMR 7238, CNRS, Sorbonne Université, Paris 75005, France
| | - Félix de Carpentier
- Institut de Biologie Paris Seine, UMR 7238, CNRS, Sorbonne Université, Paris 75005, France
- Doctoral School of Plant Sciences, Université Paris-Saclay, Saint-Aubin 91190, France
| | - Phuc André
- Institut de Biologie Paris Seine, UMR 7238, CNRS, Sorbonne Université, Paris 75005, France
| | - Christophe H Marchand
- Institut de Biologie Paris Seine, UMR 7238, CNRS, Sorbonne Université, Paris 75005, France
- Institut de Biologie Physico-Chimique, Centre National de la Recherche Scientifique (CNRS), Paris F-75005, France
| | - Antoine Danon
- Institut de Biologie Paris Seine, UMR 7238, CNRS, Sorbonne Université, Paris 75005, France
| |
Collapse
|
2
|
Nievergelt AP, Diener DR, Bogdanova A, Brown T, Pigino G. Protocol for precision editing of endogenous Chlamydomonas reinhardtii genes with CRISPR-Cas. STAR Protoc 2024; 5:102774. [PMID: 38096061 PMCID: PMC10762519 DOI: 10.1016/j.xpro.2023.102774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 09/21/2023] [Accepted: 11/28/2023] [Indexed: 01/06/2024] Open
Abstract
CRISPR-Cas genome engineering in the unicellular green algal model Chlamydomonas reinhardtii has until recently suffered from low integration efficiencies despite traditional genetics being well established. Here, we present a protocol for efficient homology-directed knockin mutagenesis in all commonly used strains of Chlamydomonas. We describe steps for scarless integration of fusion tags and sequence modifications of almost all proteins without the need for a preceding mutant line. We further empower this genetic-editing approach by efficient crossing and highly robust screening protocols. For complete details on the use and execution of this protocol, please refer to Nievergelt et al. (2023).1.
Collapse
Affiliation(s)
- Adrian Pascal Nievergelt
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany; Human Technopole, V.le Rita Levi-Montalcini, 1, 20017 Milan, Italy.
| | - Dennis Ray Diener
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany
| | - Aliona Bogdanova
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany
| | - Thomas Brown
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany; DRESDEN-concept Genome Center (DcGC), Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Dresden, Germany
| | - Gaia Pigino
- Human Technopole, V.le Rita Levi-Montalcini, 1, 20017 Milan, Italy.
| |
Collapse
|
3
|
Jareonsin S, Mahanil K, Phinyo K, Srinuanpan S, Pekkoh J, Kameya M, Arai H, Ishii M, Chundet R, Sattayawat P, Pumas C. Unlocking microalgal host-exploring dark-growing microalgae transformation for sustainable high-value phytochemical production. Front Bioeng Biotechnol 2023; 11:1296216. [PMID: 38026874 PMCID: PMC10666632 DOI: 10.3389/fbioe.2023.1296216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 10/23/2023] [Indexed: 12/01/2023] Open
Abstract
Microalgae have emerged as a promising, next-generation sustainable resource with versatile applications, particularly as expression platforms and green cell factories. They possess the ability to overcome the limitations of terrestrial plants, such non-arable land, water scarcity, time-intensive growth, and seasonal changes. However, the heterologous expression of interested genes in microalgae under heterotrophic cultivation (dark mode) remains a niche area within the field of engineering technologies. In this study, the green microalga, Chlorella sorokiniana AARL G015 was chosen as a potential candidate due to its remarkable capacity for rapid growth in complete darkness, its ability to utilize diverse carbon sources, and its potential for wastewater treatment in a circular bioeconomy model. The aims of this study were to advance microalgal genetic engineering via dark cultivation, thereby positioning the strain as promising dark-host for expressing heterologous genes to produce high-value phytochemicals and ingredients for food and feed. To facilitate comprehensive screening based on resistance, eleven common antibiotics were tested under heterotrophic condition. As the most effective selectable markers for this strain, G418, hygromycin, and streptomycin exhibited growth inhibition rates of 98%, 93%, and 92%, respectively, ensuring robust long-term transgenic growth. Successful transformation was achieved through microalgal cell cocultivation with Agrobacterium under complete darkness verified through the expression of green fluorescence protein and β-glucuronidase. In summary, this study pioneers an alternative dark-host microalgal platform, using, Chlorella, under dark mode, presenting an easy protocol for heterologous gene transformation for microalgal host, devoid of the need for expensive equipment and light for industrial production. Furthermore, the developed genetic transformation methodology presents a sustainable way for production of high-value nutrients, dietary supplements, nutraceuticals, proteins and pharmaceuticals using heterotrophic microalgae as an innovative host system.
Collapse
Affiliation(s)
- Surumpa Jareonsin
- Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand
- Applied Microbiology (International Program) in Faculty of Science, Chiang Mai University, Chiang Mai, Thailand
| | - Kanjana Mahanil
- Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand
| | - Kittiya Phinyo
- Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand
- Office of Research Administration, Chiang Mai University, Chiang Mai, Thailand
| | - Sirasit Srinuanpan
- Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand
- Office of Research Administration, Chiang Mai University, Chiang Mai, Thailand
- Center of Excellence in Microbial Diversity and Sustainable Utilization, Chiang Mai University, Chiang Mai, Thailand
| | - Jeeraporn Pekkoh
- Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand
| | - Masafumi Kameya
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Hiroyuki Arai
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Masaharu Ishii
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Ruttaporn Chundet
- Division of Biotechnology, Faculty of Science, Maejo University, Chiangmai, Chiang Mai, Thailand
| | - Pachara Sattayawat
- Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand
| | - Chayakorn Pumas
- Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand
- Environmental Science Research Centre, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand
- Multidisciplinary Research Institute, Chiang Mai University, Chiang Mai, Thailand
| |
Collapse
|
4
|
Patwari P, Pruckner F, Fabris M. Biosensors in microalgae: A roadmap for new opportunities in synthetic biology and biotechnology. Biotechnol Adv 2023; 68:108221. [PMID: 37495181 DOI: 10.1016/j.biotechadv.2023.108221] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 06/22/2023] [Accepted: 07/22/2023] [Indexed: 07/28/2023]
Abstract
Biosensors are powerful tools to investigate, phenotype, improve and prototype microbial strains, both in fundamental research and in industrial contexts. Genetic and biotechnological developments now allow the implementation of synthetic biology approaches to novel different classes of microbial hosts, for example photosynthetic microalgae, which offer unique opportunities. To date, biosensors have not yet been implemented in phototrophic eukaryotic microorganisms, leaving great potential for novel biological and technological advancements untapped. Here, starting from selected biosensor technologies that have successfully been implemented in heterotrophic organisms, we project and define a roadmap on how these could be applied to microalgae research. We highlight novel opportunities for the development of new biosensors, identify critical challenges, and finally provide a perspective on the impact of their eventual implementation to tackle research questions and bioengineering strategies. From studying metabolism at the single-cell level to genome-wide screen approaches, and assisted laboratory evolution experiments, biosensors will greatly impact the pace of progress in understanding and engineering microalgal metabolism. We envision how this could further advance the possibilities for unraveling their ecological role, evolutionary history and accelerate their domestication, to further drive them as resource-efficient production hosts.
Collapse
Affiliation(s)
- Payal Patwari
- SDU Biotechnology, Faculty of Engineering, University of Southern Denmark, Odense M DK-5230, Denmark
| | - Florian Pruckner
- SDU Biotechnology, Faculty of Engineering, University of Southern Denmark, Odense M DK-5230, Denmark
| | - Michele Fabris
- SDU Biotechnology, Faculty of Engineering, University of Southern Denmark, Odense M DK-5230, Denmark.
| |
Collapse
|
5
|
Boisset ND, Favoino G, Meloni M, Jomat L, Cassier-Chauvat C, Zaffagnini M, Lemaire SD, Crozet P. Phosphoribulokinase abundance is not limiting the Calvin-Benson-Bassham cycle in Chlamydomonas reinhardtii. FRONTIERS IN PLANT SCIENCE 2023; 14:1230723. [PMID: 37719215 PMCID: PMC10501310 DOI: 10.3389/fpls.2023.1230723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 07/21/2023] [Indexed: 09/19/2023]
Abstract
Improving photosynthetic efficiency in plants and microalgae is of utmost importance to support the growing world population and to enable the bioproduction of energy and chemicals. Limitations in photosynthetic light conversion efficiency can be directly attributed to kinetic bottlenecks within the Calvin-Benson-Bassham cycle (CBBC) responsible for carbon fixation. A better understanding of these bottlenecks in vivo is crucial to overcome these limiting factors through bio-engineering. The present study is focused on the analysis of phosphoribulokinase (PRK) in the unicellular green alga Chlamydomonas reinhardtii. We have characterized a PRK knock-out mutant strain and showed that in the absence of PRK, Chlamydomonas cannot grow photoautotrophically while functional complementation with a synthetic construct allowed restoration of photoautotrophy. Nevertheless, using standard genetic elements, the expression of PRK was limited to 40% of the reference level in complemented strains and could not restore normal growth in photoautotrophic conditions suggesting that the CBBC is limited. We were subsequently able to overcome this initial limitation by improving the design of the transcriptional unit expressing PRK using diverse combinations of DNA parts including PRK endogenous promoter and introns. This enabled us to obtain strains with PRK levels comparable to the reference strain and even overexpressing strains. A collection of strains with PRK levels between 16% and 250% of WT PRK levels was generated and characterized. Immunoblot and growth assays revealed that a PRK content of ≈86% is sufficient to fully restore photoautotrophic growth. This result suggests that PRK is present in moderate excess in Chlamydomonas. Consistently, the overexpression of PRK did not increase photosynthetic growth indicating that that the endogenous level of PRK in Chlamydomonas is not limiting the Calvin-Benson-Bassham cycle under optimal conditions.
Collapse
Affiliation(s)
- Nicolas D. Boisset
- Laboratoire de Biologie Computationnelle et Quantitative, Institut de Biologie Parie-Seine, Sorbonne Université, CNRS, UMR 7238, Paris, France
- Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, Institut de Biologie Physico-Chimique, Sorbonne Université, CNRS, UMR 8226, Paris, France
- Doctoral School of Plant Sciences, Université Paris-Saclay, Saint-Aubin, France
| | - Giusi Favoino
- Laboratoire de Biologie Computationnelle et Quantitative, Institut de Biologie Parie-Seine, Sorbonne Université, CNRS, UMR 7238, Paris, France
| | - Maria Meloni
- Department of Pharmacy and Biotechnologies, University of Bologna, Bologna, Italy
| | - Lucile Jomat
- Laboratoire de Biologie Computationnelle et Quantitative, Institut de Biologie Parie-Seine, Sorbonne Université, CNRS, UMR 7238, Paris, France
| | - Corinne Cassier-Chauvat
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), UMR 9198, Gif-sur-Yvette, France
| | - Mirko Zaffagnini
- Department of Pharmacy and Biotechnologies, University of Bologna, Bologna, Italy
| | - Stéphane D. Lemaire
- Laboratoire de Biologie Computationnelle et Quantitative, Institut de Biologie Parie-Seine, Sorbonne Université, CNRS, UMR 7238, Paris, France
- Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, Institut de Biologie Physico-Chimique, Sorbonne Université, CNRS, UMR 8226, Paris, France
| | - Pierre Crozet
- Laboratoire de Biologie Computationnelle et Quantitative, Institut de Biologie Parie-Seine, Sorbonne Université, CNRS, UMR 7238, Paris, France
- Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, Institut de Biologie Physico-Chimique, Sorbonne Université, CNRS, UMR 8226, Paris, France
- Polytech-Sorbonne, Sorbonne Université, Paris, France
| |
Collapse
|
6
|
Nievergelt AP, Diener DR, Bogdanova A, Brown T, Pigino G. Efficient precision editing of endogenous Chlamydomonas reinhardtii genes with CRISPR-Cas. CELL REPORTS METHODS 2023; 3:100562. [PMID: 37671018 PMCID: PMC10475843 DOI: 10.1016/j.crmeth.2023.100562] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 11/11/2022] [Accepted: 07/28/2023] [Indexed: 09/07/2023]
Abstract
CRISPR-Cas genome engineering in the unicellular green algal model Chlamydomonas reinhardtii has until now been primarily applied to targeted gene disruption, whereas scarless knockin transgenesis has generally been considered difficult in practice. We have developed an efficient homology-directed method for knockin mutagenesis in Chlamydomonas by delivering CRISPR-Cas ribonucleoproteins and a linear double-stranded DNA (dsDNA) donor into cells by electroporation. Our method allows scarless integration of fusion tags and sequence modifications of proteins without the need for a preceding mutant line. We also present methods for high-throughput crossing of transformants and a custom quantitative PCR (qPCR)-based high-throughput screening of mutants as well as meiotic progeny. We demonstrate how to use this pipeline to facilitate the generation of mutant lines without residual selectable markers by co-targeted insertion. Finally, we describe how insertional cassettes can be erroneously mutated during insertion and suggest strategies to select for lines that are modified as designed.
Collapse
Affiliation(s)
- Adrian Pascal Nievergelt
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany
| | - Dennis Ray Diener
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany
| | - Aliona Bogdanova
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany
| | - Thomas Brown
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany
- DRESDEN-concept Genome Center (DcGC), Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Dresden, Germany
| | - Gaia Pigino
- Human Technopole, V.le Rita Levi-Montalcini, 1, 20017 Milan, Italy
| |
Collapse
|
7
|
Perozeni F, Baier T. Current Nuclear Engineering Strategies in the Green Microalga Chlamydomonas reinhardtii. Life (Basel) 2023; 13:1566. [PMID: 37511941 PMCID: PMC10381326 DOI: 10.3390/life13071566] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 07/07/2023] [Accepted: 07/13/2023] [Indexed: 07/30/2023] Open
Abstract
The green model microalga Chlamydomonas reinhardtii recently emerged as a sustainable production chassis for the efficient biosynthesis of recombinant proteins and high-value metabolites. Its capacity for scalable, rapid and light-driven growth in minimal salt solutions, its simplicity for genetic manipulation and its "Generally Recognized As Safe" (GRAS) status are key features for its application in industrial biotechnology. Although nuclear transformation has typically resulted in limited transgene expression levels, recent developments now allow the design of powerful and innovative bioproduction concepts. In this review, we summarize the main obstacles to genetic engineering in C. reinhardtii and describe all essential aspects in sequence adaption and vector design to enable sufficient transgene expression from the nuclear genome. Several biotechnological examples of successful engineering serve as blueprints for the future establishment of C. reinhardtii as a green cell factory.
Collapse
Affiliation(s)
- Federico Perozeni
- Department of Biotechnology, University of Verona, 37134 Verona, Italy
| | - Thomas Baier
- Algae Biotechnology and Bioenergy, Faculty of Biology, Center for Biotechnology (CeBiTec), Bielefeld University, 33615 Bielefeld, Germany
| |
Collapse
|
8
|
Kong F, Li M, Liu K, Ge Y, Yamasaki T, Beyly-Adriano A, Ohama T, Li-Beisson Y. Efficient approaches for nuclear transgene stacking in the unicellular green microalga Chlamydomonas reinhardtii. ALGAL RES 2023. [DOI: 10.1016/j.algal.2023.103048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
|
9
|
de Carpentier F, Maes A, Marchand CH, Chung C, Durand C, Crozet P, Lemaire SD, Danon A. How abiotic stress-induced socialization leads to the formation of massive aggregates in Chlamydomonas. PLANT PHYSIOLOGY 2022; 190:1927-1940. [PMID: 35775951 PMCID: PMC9614484 DOI: 10.1093/plphys/kiac321] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 06/16/2022] [Indexed: 05/05/2023]
Abstract
Multicellular organisms implement a set of reactions involving signaling and cooperation between different types of cells. Unicellular organisms, on the other hand, activate defense systems that involve collective behaviors between individual organisms. In the unicellular model alga Chlamydomonas (Chlamydomonas reinhardtii), the existence and the function of collective behaviors mechanisms in response to stress remain mostly at the level of the formation of small structures called palmelloids. Here, we report the characterization of a mechanism of abiotic stress response that Chlamydomonas can trigger to form massive multicellular structures. We showed that these aggregates constitute an effective bulwark within which the cells are efficiently protected from the toxic environment. We generated a family of mutants that aggregate spontaneously, the socializer (saz) mutants, of which saz1 is described here in detail. We took advantage of the saz mutants to implement a large-scale multiomics approach that allowed us to show that aggregation is not the result of passive agglutination, but rather genetic reprogramming and substantial modification of the secretome. The reverse genetic analysis we conducted allowed us to identify positive and negative regulators of aggregation and to make hypotheses on how this process is controlled in Chlamydomonas.
Collapse
Affiliation(s)
- Félix de Carpentier
- Institut de Biologie Physico-Chimique, UMR 8226, CNRS, Sorbonne Université, 75005 Paris, France
- Institut de Biologie Paris-Seine, UMR 7238, CNRS, Sorbonne Université, 75005 Paris, France
- Université Paris-Saclay, 91190 Saint-Aubin, France
| | - Alexandre Maes
- Institut de Biologie Physico-Chimique, UMR 8226, CNRS, Sorbonne Université, 75005 Paris, France
| | - Christophe H Marchand
- Institut de Biologie Physico-Chimique, UMR 8226, CNRS, Sorbonne Université, 75005 Paris, France
- Institut de Biologie Paris-Seine, UMR 7238, CNRS, Sorbonne Université, 75005 Paris, France
| | - Céline Chung
- Institut de Biologie Physico-Chimique, UMR 8226, CNRS, Sorbonne Université, 75005 Paris, France
| | - Cyrielle Durand
- Institut de Biologie Physico-Chimique, UMR 8226, CNRS, Sorbonne Université, 75005 Paris, France
| | - Pierre Crozet
- Institut de Biologie Physico-Chimique, UMR 8226, CNRS, Sorbonne Université, 75005 Paris, France
- Institut de Biologie Paris-Seine, UMR 7238, CNRS, Sorbonne Université, 75005 Paris, France
- Polytech-Sorbonne, Sorbonne Université, 75005 Paris, France
| | - Stéphane D Lemaire
- Institut de Biologie Physico-Chimique, UMR 8226, CNRS, Sorbonne Université, 75005 Paris, France
- Institut de Biologie Paris-Seine, UMR 7238, CNRS, Sorbonne Université, 75005 Paris, France
| | | |
Collapse
|
10
|
New destination vectors facilitate Modular Cloning for Chlamydomonas. Curr Genet 2022; 68:531-536. [PMID: 35429260 PMCID: PMC9279246 DOI: 10.1007/s00294-022-01239-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 03/04/2022] [Accepted: 03/24/2022] [Indexed: 11/30/2022]
Abstract
Synthetic Biology is revolutionizing biological research by introducing principles of mechanical engineering, including the standardization of genetic parts and standardized part assembly routes. Both are realized in the Modular Cloning (MoClo) strategy. MoClo allows for the rapid and robust assembly of individual genes and multigene clusters, enabling iterative cycles of gene design, construction, testing, and learning in short time. This is particularly true if generation times of target organisms are short, as is the case for the unicellular green alga Chlamydomonas reinhardtii. Testing a gene of interest in Chlamydomonas with MoClo requires two assembly steps, one for the gene of interest itself and another to combine it with a selection marker. To reduce this to a single assembly step, we constructed five new destination vectors. They contain genes conferring resistance to commonly used antibiotics in Chlamydomonas and a site for the direct assembly of basic genetic parts. The vectors employ red/white color selection and, therefore, do not require costly compounds like X-gal and IPTG. mCherry expression is used to demonstrate the functionality of these vectors.
Collapse
|
11
|
Sproles AE, Berndt A, Fields FJ, Mayfield SP. Improved high-throughput screening technique to rapidly isolate Chlamydomonas transformants expressing recombinant proteins. Appl Microbiol Biotechnol 2022; 106:1677-1689. [PMID: 35129657 PMCID: PMC8882119 DOI: 10.1007/s00253-022-11790-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 01/17/2022] [Accepted: 01/18/2022] [Indexed: 12/20/2022]
Abstract
Abstract
The single-celled eukaryotic green alga Chlamydomonas reinhardtii has long been a model system for developing genetic tools for algae, and is also considered a potential platform for the production of high-value recombinant proteins. Identifying transformants with high levels of recombinant protein expression has been a challenge in this organism, as random integration of transgenes into the nuclear genome leads to low frequency of cell lines with high gene expression. Here, we describe the design of an optimized vector for the expression of recombinant proteins in Chlamydomonas, that when transformed and screened using a dual antibiotic selection, followed by screening using fluorescence activated cell sorting (FACS), permits rapid identification and isolation of microalgal transformants with high expression of a recombinant protein. This process greatly reduces the time required for the screening process, and can produce large populations of recombinant algae transformants with between 60 and 100% of cells producing the recombinant protein of interest, in as little as 3 weeks, that can then be used for whole population sequencing or individual clone analysis. Utilizing this new vector and high-throughput screening (HTS) process resulted in an order of magnitude improvement over existing methods, which normally produced under 1% of algae transformants expressing the protein of interest. This process can be applied to other algal strains and recombinant proteins to enhance screening efficiency, thereby speeding up the discovery and development of algal-derived recombinant protein products. Key points • A protein expression vector using double-antibiotic resistance genes was designed • Double antibiotic selection causes fewer colonies with more positive for phenotype • Coupling the new vector with FACS improves microalgal screening efficiency > 60% Supplementary Information The online version contains supplementary material available at 10.1007/s00253-022-11790-9.
Collapse
Affiliation(s)
- Ashley E Sproles
- The California Center for Algae Biotechnology, University of California, San Diego, La Jolla, CA, USA.,Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Anthony Berndt
- The California Center for Algae Biotechnology, University of California, San Diego, La Jolla, CA, USA.,Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Francis J Fields
- The California Center for Algae Biotechnology, University of California, San Diego, La Jolla, CA, USA.,Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Stephen P Mayfield
- The California Center for Algae Biotechnology, University of California, San Diego, La Jolla, CA, USA. .,Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA.
| |
Collapse
|
12
|
Schroda M, Remacle C. Molecular Advancements Establishing Chlamydomonas as a Host for Biotechnological Exploitation. FRONTIERS IN PLANT SCIENCE 2022; 13:911483. [PMID: 35845675 PMCID: PMC9277225 DOI: 10.3389/fpls.2022.911483] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Accepted: 06/07/2022] [Indexed: 05/13/2023]
Abstract
Chlamydomonas reinhardtii is emerging as a production platform for biotechnological purposes thanks to recent achievements, which we briefly summarize in this review. Firstly, robust nuclear transgene expression is now possible because several impressive improvements have been made in recent years. Strains allowing efficient and stable nuclear transgene expression are available and were recently made more amenable to rational biotechnological approaches by enabling genetic crosses and identifying their causative mutation. The MoClo synthetic biology strategy, based on Golden Gate cloning, was developed for Chlamydomonas and includes a growing toolkit of more than 100 genetic parts that can be robustly and rapidly assembled in a predefined order. This allows for rapid iterative cycles of transgene design, building, testing, and learning. Another major advancement came from various findings improving transgene design and expression such as the systematic addition of introns into codon-optimized coding sequences. Lastly, the CRISPR/Cas9 technology for genome editing has undergone several improvements since its first successful report in 2016, which opens the possibility of optimizing biosynthetic pathways by switching off competing ones. We provide a few examples demonstrating that all these recent developments firmly establish Chlamydomonas as a chassis for synthetic biology and allow the rewiring of its metabolism to new capabilities.
Collapse
Affiliation(s)
- Michael Schroda
- Molecular Biotechnology and Systems Biology, TU Kaiserslautern, Kaiserslautern, Germany
| | - Claire Remacle
- Genetics and Physiology of Microalgae, InBios/Phytosystems Research Unit, University of Liege, Liege, Belgium
- *Correspondence: Claire Remacle,
| |
Collapse
|
13
|
Fujiwara T, Hirooka S, Miyagishima SY. A cotransformation system of the unicellular red alga Cyanidioschyzon merolae with blasticidin S deaminase and chloramphenicol acetyltransferase selectable markers. BMC PLANT BIOLOGY 2021; 21:573. [PMID: 34863100 PMCID: PMC8642924 DOI: 10.1186/s12870-021-03365-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Accepted: 11/24/2021] [Indexed: 05/24/2023]
Abstract
BACKGROUND The unicellular red alga Cyanidioschyzon merolae exhibits a very simple cellular and genomic architecture. In addition, procedures for genetic modifications, such as gene targeting by homologous recombination and inducible/repressible gene expression, have been developed. However, only two markers for selecting transformants, uracil synthase (URA) and chloramphenicol acetyltransferase (CAT), are available in this alga. Therefore, manipulation of two or more different chromosomal loci in the same strain in C. merolae is limited. RESULTS This study developed a nuclear targeting and transformant selection system using an antibiotics blasticidin S (BS) and the BS deaminase (BSD) selectable marker by homologous recombination in C. merolae. In addition, this study has succeeded in simultaneously modifying two different chromosomal loci by a single-step cotransformation based on the combination of BSD and CAT selectable markers. A C. merolae strain that expresses mitochondrion-targeted mSCARLET (with the BSD marker) and mVENUS (with the CAT marker) from different chromosomal loci was generated with this procedure. CONCLUSIONS The newly developed BSD selectable marker enables an additional genetic modification to the already generated C. merolae transformants based on the URA or CAT system. Furthermore, the cotransformation system facilitates multiple genetic modifications. These methods and the simple nature of the C. merolae cellular and genomic architecture will facilitate studies on several phenomena common to photosynthetic eukaryotes.
Collapse
Affiliation(s)
- Takayuki Fujiwara
- Department of Gene Function and Phenomics, National Institute of Genetics, Mishima, Shizuoka, 411-8540, Japan.
- Department of Genetics, Graduate University for Advanced Studies, SOKENDAI, Mishima, Shizuoka, 411-8540, Japan.
| | - Shunsuke Hirooka
- Department of Gene Function and Phenomics, National Institute of Genetics, Mishima, Shizuoka, 411-8540, Japan
| | - Shin-Ya Miyagishima
- Department of Gene Function and Phenomics, National Institute of Genetics, Mishima, Shizuoka, 411-8540, Japan.
- Department of Genetics, Graduate University for Advanced Studies, SOKENDAI, Mishima, Shizuoka, 411-8540, Japan.
| |
Collapse
|