1
|
Shin SE, Koh HG, Park K, Park SH, Chang YK, Kang NK. Increasing lipid production in Chlamydomonas reinhardtii through genetic introduction for the overexpression of glyceraldehyde-3-phosphate dehydrogenase. Front Bioeng Biotechnol 2024; 12:1396127. [PMID: 38707501 PMCID: PMC11066295 DOI: 10.3389/fbioe.2024.1396127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Accepted: 04/05/2024] [Indexed: 05/07/2024] Open
Abstract
Microalgae, valued for their sustainability and CO2 fixation capabilities, are emerging as promising sources of biofuels and high-value compounds. This study aimed to boost lipid production in C. reinhardtii by overexpressing chloroplast glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a key enzyme in the Calvin cycle and glycolysis, under the control of a nitrogen-inducible NIT1 promoter, to positively impact overall carbon metabolism. The standout transformant, PNG#7, exhibited significantly increased lipid production under nitrogen starvation, with biomass rising by 44% and 76% on days 4 and 16, respectively. Fatty acid methyl ester (FAME) content in PNG#7 surged by 2.4-fold and 2.1-fold, notably surpassing the wild type (WT) in lipid productivity by 3.4 and 3.7 times on days 4 and 16, respectively. Transcriptome analysis revealed a tenfold increase in transgenic GAPDH expression and significant upregulation of genes involved in fatty acid and triacylglycerol synthesis, especially the gene encoding acyl-carrier protein gene (ACP, Cre13. g577100. t1.2). In contrast, genes related to cellulose synthesis were downregulated. Single Nucleotide Polymorphism (SNP)/Indel analysis indicated substantial DNA modifications, which likely contributed to the observed extensive transcriptomic and phenotypic changes. These findings suggest that overexpressing chloroplast GAPDH, coupled with genetic modifications, effectively enhances lipid synthesis in C. reinhardtii. This study not only underscores the potential of chloroplast GAPDH overexpression in microalgal lipid synthesis but also highlights the expansive potential of metabolic engineering in microalgae for biofuel production.
Collapse
Affiliation(s)
- Sung-Eun Shin
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Hyun Gi Koh
- Department of Biological and Chemical Engineering, Hongik University, Sejong, Republic of Korea
| | - Kyungmoon Park
- Department of Biological and Chemical Engineering, Hongik University, Sejong, Republic of Korea
| | - See-Hyoung Park
- Department of Biological and Chemical Engineering, Hongik University, Sejong, Republic of Korea
| | - Yong Keun Chang
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Nam Kyu Kang
- Department of Chemical Engineering, College of Engineering, Kyung Hee University, Yongin, Republic of Korea
| |
Collapse
|
2
|
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
|
3
|
Chronological transcriptome changes induced by exposure to cyanoacrylate resin nanoparticles in Chlamydomonas reinhardtii with a focus on ROS development and cell wall lysis-related genes. ALGAL RES 2022. [DOI: 10.1016/j.algal.2022.102884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
4
|
Wakao S, Shih PM, Guan K, Schackwitz W, Ye J, Patel D, Shih RM, Dent RM, Chovatia M, Sharma A, Martin J, Wei CL, Niyogi KK. Discovery of photosynthesis genes through whole-genome sequencing of acetate-requiring mutants of Chlamydomonas reinhardtii. PLoS Genet 2021; 17:e1009725. [PMID: 34492001 PMCID: PMC8448359 DOI: 10.1371/journal.pgen.1009725] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 09/17/2021] [Accepted: 07/19/2021] [Indexed: 11/18/2022] Open
Abstract
Large-scale mutant libraries have been indispensable for genetic studies, and the development of next-generation genome sequencing technologies has greatly advanced efforts to analyze mutants. In this work, we sequenced the genomes of 660 Chlamydomonas reinhardtii acetate-requiring mutants, part of a larger photosynthesis mutant collection previously generated by insertional mutagenesis with a linearized plasmid. We identified 554 insertion events from 509 mutants by mapping the plasmid insertion sites through paired-end sequences, in which one end aligned to the plasmid and the other to a chromosomal location. Nearly all (96%) of the events were associated with deletions, duplications, or more complex rearrangements of genomic DNA at the sites of plasmid insertion, and together with deletions that were unassociated with a plasmid insertion, 1470 genes were identified to be affected. Functional annotations of these genes were enriched in those related to photosynthesis, signaling, and tetrapyrrole synthesis as would be expected from a library enriched for photosynthesis mutants. Systematic manual analysis of the disrupted genes for each mutant generated a list of 253 higher-confidence candidate photosynthesis genes, and we experimentally validated two genes that are essential for photoautotrophic growth, CrLPA3 and CrPSBP4. The inventory of candidate genes includes 53 genes from a phylogenomically defined set of conserved genes in green algae and plants. Altogether, 70 candidate genes encode proteins with previously characterized functions in photosynthesis in Chlamydomonas, land plants, and/or cyanobacteria; 14 genes encode proteins previously shown to have functions unrelated to photosynthesis. Among the remaining 169 uncharacterized genes, 38 genes encode proteins without any functional annotation, signifying that our results connect a function related to photosynthesis to these previously unknown proteins. This mutant library, with genome sequences that reveal the molecular extent of the chromosomal lesions and resulting higher-confidence candidate genes, will aid in advancing gene discovery and protein functional analysis in photosynthesis.
Collapse
Affiliation(s)
- Setsuko Wakao
- Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- Department of Plant and Microbial Biology, University of California, Berkeley, California, United States of America
| | - Patrick M. Shih
- Department of Plant and Microbial Biology, University of California, Berkeley, California, United States of America
- Division of Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- Feedstocks Division, Joint BioEnergy Institute, Emeryville, California, United States of America
- Innovative Genomics Institute, University of California, Berkeley, California, United States of America
| | - Katharine Guan
- Department of Plant and Microbial Biology, University of California, Berkeley, California, United States of America
- Howard Hughes Medical Institute, University of California, Berkeley, California, United States of America
| | - Wendy Schackwitz
- Joint Genome Institute, Berkeley, California, United States of America
| | - Joshua Ye
- Department of Plant and Microbial Biology, University of California, Berkeley, California, United States of America
- Howard Hughes Medical Institute, University of California, Berkeley, California, United States of America
| | - Dhruv Patel
- Department of Plant and Microbial Biology, University of California, Berkeley, California, United States of America
| | - Robert M. Shih
- Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
| | - Rachel M. Dent
- Department of Plant and Microbial Biology, University of California, Berkeley, California, United States of America
| | - Mansi Chovatia
- Joint Genome Institute, Berkeley, California, United States of America
| | - Aditi Sharma
- Joint Genome Institute, Berkeley, California, United States of America
| | - Joel Martin
- Joint Genome Institute, Berkeley, California, United States of America
| | - Chia-Lin Wei
- Joint Genome Institute, Berkeley, California, United States of America
| | - Krishna K. Niyogi
- Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- Department of Plant and Microbial Biology, University of California, Berkeley, California, United States of America
- Howard Hughes Medical Institute, University of California, Berkeley, California, United States of America
| |
Collapse
|
5
|
Thomy J, Sanchez F, Gut M, Cruz F, Alioto T, Piganeau G, Grimsley N, Yau S. Combining Nanopore and Illumina Sequencing Permits Detailed Analysis of Insertion Mutations and Structural Variations Produced by PEG-Mediated Transformation in Ostreococcus tauri. Cells 2021; 10:cells10030664. [PMID: 33802698 PMCID: PMC8002553 DOI: 10.3390/cells10030664] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 03/09/2021] [Accepted: 03/15/2021] [Indexed: 12/13/2022] Open
Abstract
Ostreococcus tauri is a simple unicellular green alga representing an ecologically important group of phytoplankton in oceans worldwide. Modern molecular techniques must be developed in order to understand the mechanisms that permit adaptation of microalgae to their environment. We present for the first time in O. tauri a detailed characterization of individual genomic integration events of foreign DNA of plasmid origin after PEG-mediated transformation. Vector integration occurred randomly at a single locus in the genome and mainly as a single copy. Thus, we confirmed the utility of this technique for insertional mutagenesis. While the mechanism of double-stranded DNA repair in the O. tauri model remains to be elucidated, we clearly demonstrate by genome resequencing that the integration of the vector leads to frequent structural variations (deletions/insertions and duplications) and some chromosomal rearrangements in the genome at the insertion loci. Furthermore, we often observed variations in the vector sequence itself. From these observations, we speculate that a nonhomologous end-joining-like mechanism is employed during random insertion events, as described in plants and other freshwater algal models. PEG-mediated transformation is therefore a promising molecular biology tool, not only for functional genomic studies, but also for biotechnological research in this ecologically important marine alga.
Collapse
Affiliation(s)
- Julie Thomy
- Sorbonne Université, CNRS, UMR 7232 Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France; (J.T.); (F.S.); (G.P.)
| | - Frederic Sanchez
- Sorbonne Université, CNRS, UMR 7232 Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France; (J.T.); (F.S.); (G.P.)
| | - Marta Gut
- CNAG-CRG, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Baldiri i Reixac 4, 08028 Barcelona, Spain; (M.G.); (F.C.); (T.A.)
- Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain
| | - Fernando Cruz
- CNAG-CRG, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Baldiri i Reixac 4, 08028 Barcelona, Spain; (M.G.); (F.C.); (T.A.)
| | - Tyler Alioto
- CNAG-CRG, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Baldiri i Reixac 4, 08028 Barcelona, Spain; (M.G.); (F.C.); (T.A.)
- Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain
| | - Gwenael Piganeau
- Sorbonne Université, CNRS, UMR 7232 Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France; (J.T.); (F.S.); (G.P.)
| | - Nigel Grimsley
- Sorbonne Université, CNRS, UMR 7232 Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France; (J.T.); (F.S.); (G.P.)
- Correspondence: (N.G.); (S.Y.)
| | - Sheree Yau
- Sorbonne Université, CNRS, UMR 7232 Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France; (J.T.); (F.S.); (G.P.)
- Correspondence: (N.G.); (S.Y.)
| |
Collapse
|
6
|
Douchi D, Mosey M, Astling DP, Knoshaug EP, Nag A, McGowen J, Laurens LM. Nuclear and chloroplast genome engineering of a productive non-model alga Desmodesmus armatus: Insights into unusual and selective acquisition mechanisms for foreign DNA. ALGAL RES 2021. [DOI: 10.1016/j.algal.2020.102152] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
7
|
Simple innovative adaptor to improve genome walking with convenient PCR. J Genet Eng Biotechnol 2020; 18:64. [PMID: 33083895 PMCID: PMC7575660 DOI: 10.1186/s43141-020-00082-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 09/30/2020] [Indexed: 11/10/2022]
Abstract
BACKGROUND Various polymerase chain reaction (PCR)-based methods have been applied for the development of genome walking (GW) technique. These methods which could be based on the application of restriction enzymes or primers have various efficiencies to identify the unknown nucleotide sequences. The present study was conducted to design a new innovative double-strand adaptor using MAP30 gene sequence of Momordica charantia plant as a model to improve genome walking with convenient PCR. RESULTS The adaptor was designed using multiple restriction sites of Hind III, BamH I, EcoR I, and Bgl II enzymes with no restriction site in a known sequence of the MAP30 gene. In addition, no modification was required to add phosphate, amine, or other groups to the adaptor, since restriction enzyme digestion of double-strand adaptor provided the 5' phosphate group. Here, preparation of the phosphate group in the genomic DNA of the plant digestion with restriction enzymes was performed followed by ligation with digested adaptor containing 5' phosphate group. CONCLUSION PCR was done to amplify the unknown sequence using MAP30 gene-specific primer and adaptor primer. Results confirmed the ability of the technique for successful identification of the sequence. Consequently, a newly designed adaptor in the developed technique reduced the time and cost of the method compared to the conventional genome walking; also, cloning and culturing of bacterial steps could be eliminated.
Collapse
|
8
|
Achievements and challenges of genetic engineering of the model green alga Chlamydomonas reinhardtii. ALGAL RES 2020. [DOI: 10.1016/j.algal.2020.101986] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
9
|
Metabolic engineering of ketocarotenoids biosynthetic pathway in Chlamydomonas reinhardtii strain CC-4102. Sci Rep 2020; 10:10688. [PMID: 32612116 PMCID: PMC7329852 DOI: 10.1038/s41598-020-67756-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 05/29/2020] [Indexed: 11/23/2022] Open
Abstract
In Chlamydomonas reinhardtii, ketocarotenoid biosynthesis is limited to the diploid zygospore stage. In this study, we attempted to engineer the ketocarotenoid pathway into Chlamydomonas haploid vegetative green cells by overexpressing the key enzyme ß-carotene ketolase (CrBKT). We chose strain CC-4102 for the approach; competitive pathways, α-carotene biosynthesis and xanthophyll cycle are silenced in this strain. Driven by the strong constitutive HSP70/RBCS2 promoter CrBKT overexpression resulted in the production of canthaxanthin, the ketolation product from ß-carotene as well as a drastic reduction in the chlorophyll concentration. Intriguingly, these phenotypes could only be detected from lines transformed and grown heterotrophically in the dark. Once exposed to light, these transformants lost the aforementioned phenotypes as well as their antibiotic resistance. This phenomenon is in agreement with the fact that we were unable to recover any canthaxanthin-producing line among light-selected transformants.
Collapse
|
10
|
Picariello T, Hou Y, Kubo T, McNeill NA, Yanagisawa HA, Oda T, Witman GB. TIM, a targeted insertional mutagenesis method utilizing CRISPR/Cas9 in Chlamydomonas reinhardtii. PLoS One 2020; 15:e0232594. [PMID: 32401787 PMCID: PMC7219734 DOI: 10.1371/journal.pone.0232594] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 04/18/2020] [Indexed: 01/16/2023] Open
Abstract
Generation and subsequent analysis of mutants is critical to understanding the functions of genes and proteins. Here we describe TIM, an efficient, cost-effective, CRISPR-based targeted insertional mutagenesis method for the model organism Chlamydomonas reinhardtii. TIM utilizes delivery into the cell of a Cas9-guide RNA (gRNA) ribonucleoprotein (RNP) together with exogenous double-stranded (donor) DNA. The donor DNA contains gene-specific homology arms and an integral antibiotic-resistance gene that inserts at the double-stranded break generated by Cas9. After optimizing multiple parameters of this method, we were able to generate mutants for six out of six different genes in two different cell-walled strains with mutation efficiencies ranging from 40% to 95%. Furthermore, these high efficiencies allowed simultaneous targeting of two separate genes in a single experiment. TIM is flexible with regard to many parameters and can be carried out using either electroporation or the glass-bead method for delivery of the RNP and donor DNA. TIM achieves a far higher mutation rate than any previously reported for CRISPR-based methods in C. reinhardtii and promises to be effective for many, if not all, non-essential nuclear genes.
Collapse
Affiliation(s)
- Tyler Picariello
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Yuqing Hou
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Tomohiro Kubo
- Department of Anatomy and Structural Biology, Interdisciplinary Graduate School, University of Yamanashi, Chuo, Yamanashi, Japan
| | - Nathan A. McNeill
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | | | - Toshiyuki Oda
- Department of Anatomy and Structural Biology, Interdisciplinary Graduate School, University of Yamanashi, Chuo, Yamanashi, Japan
| | - George B. Witman
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| |
Collapse
|
11
|
Lin H, Cliften PF, Dutcher SK. MAPINS, a Highly Efficient Detection Method That Identifies Insertional Mutations and Complex DNA Rearrangements. PLANT PHYSIOLOGY 2018; 178:1436-1447. [PMID: 30206105 PMCID: PMC6288735 DOI: 10.1104/pp.18.00474] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 08/29/2018] [Indexed: 05/20/2023]
Abstract
Insertional mutagenesis, in which a piece of exogenous DNA is integrated randomly into the genomic DNA of the recipient cell, is a useful method to generate new mutants with phenotypes of interest. The unicellular green alga Chlamydomonas reinhardtii is an outstanding model for studying many biological processes. We developed a new computational algorithm, MAPINS (mapping insertions), to efficiently identify insertion sites created by the integration of an APHVIII (aminoglycoside 3'-phosphotransferase VIII) cassette that confers paromomycin resistance. Using whole-genome sequencing data, this method eliminates the need for genomic DNA manipulation and retains all the sequencing information provided by paired-end sequencing. We experimentally verified 38 insertion sites out of 41 sites (93%) identified by MAPINS from 20 paromomycin-resistant strains. Using meiotic analysis of 18 of these strains, we identified insertion sites that completely cosegregate with paromomycin resistance. In six of the seven strains with a mutant phenotype, we demonstrated complete cosegregation of the mutant phenotype and the verified insertion site. In addition, we provide direct evidence of complex rearrangements of genomic DNA in five strains, three of which involve the APHVIII insertion site. We suggest that strains obtained by insertional mutagenesis are more complicated than expected from previous analyses in Chlamydomonas To map the locations of some complex insertions, we designed 49 molecular markers based on differences identified via whole-genome sequencing between wild-type strains CC-124 and CC-125. Overall, MAPINS provides a low-cost, efficient method to characterize insertional mutants in Chlamydomonas.
Collapse
Affiliation(s)
- Huawen Lin
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Paul F Cliften
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Susan K Dutcher
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri 63110
| |
Collapse
|
12
|
Dehghani J, Movafeghi A, Barzegari A, Barar J. Efficient and stable transformation of Dunaliella pseudosalina by 3 strains of Agrobacterium tumefaciens. ACTA ACUST UNITED AC 2017; 7:247-254. [PMID: 29435432 PMCID: PMC5801536 DOI: 10.15171/bi.2017.29] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Revised: 08/30/2017] [Accepted: 09/05/2017] [Indexed: 12/30/2022]
Abstract
![]()
Introduction:
Several platforms including mammalian, plant and insect cells as well as bacteria, yeasts, and microalgae are available for the production of recombinant proteins. Low efficiency of delivery systems, extracellular and intracellular degradation of foreign genes during transformation, difficulties in targeting and importing into the nucleus, and finally problems in integration into nuclear genome are the most bottlenecks of classical plasmids for producing recombinant proteins. Owing to high growth rate, no common pathogen with humans, being utilized as humans’ food, and capability to perform N-glycosylation, microalgae are proposed as an ideal system for such biotechnological approaches. Here, Agrobacterium tumefaciens is introduced as an alternative tool for transformation of the microalga Dunaliella pseudosalina.
Methods: The transformation of gfp gene into the D. pseudosalina was evaluated by three strains including EHA101, GV3301 and GV3850 of A. tumefaciens. The integrating and expression of gfp gene were determined by PCR, RT-PCR, Q-PCR and SDS-PAGE analyses.
Results: The T-DNA of pCAMBIA1304 plasmid was successfully integrated into the genome of the microalgal cells. Although all of the strains were able to transform the algal cells, GV3301 possessed higher potential to transform the microalgal cells in comparison to EHA101 and GV3850 strains. Moreover, the stability of gfp gene was successfully established during a course of two months period in the microalgal genome.
Conclusion : Agrobacterium is introduced as a competent system for stable transformation of Dunaliella strains in order to produce eukaryotic recombinant proteins.
Collapse
Affiliation(s)
- Jaber Dehghani
- Department of Plant Biology, Faculty of Natural Science, University of Tabriz, 29th Bahman Blvd, Tabriz, Iran.,Research Center for Pharmaceutical Nanotechnology, Tabriz University of Medical Science, Tabriz, Iran
| | - Ali Movafeghi
- Department of Plant Biology, Faculty of Natural Science, University of Tabriz, 29th Bahman Blvd, Tabriz, Iran
| | - Abolfazl Barzegari
- Research Center for Pharmaceutical Nanotechnology, Tabriz University of Medical Science, Tabriz, Iran.,School of Advanced Biomedical Sciences, Tabriz University of Medical Science, Daneshgah street, Tabriz, Iran
| | - Jaleh Barar
- Research Center for Pharmaceutical Nanotechnology, Tabriz University of Medical Science, Tabriz, Iran
| |
Collapse
|
13
|
Machingura MC, Bajsa-Hirschel J, Laborde SM, Schwartzenburg JB, Mukherjee B, Mukherjee A, Pollock SV, Förster B, Price GD, Moroney JV. Identification and characterization of a solute carrier, CIA8, involved in inorganic carbon acclimation in Chlamydomonas reinhardtii. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:3879-3890. [PMID: 28633328 PMCID: PMC5853530 DOI: 10.1093/jxb/erx189] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 05/12/2017] [Indexed: 05/22/2023]
Abstract
The supply of inorganic carbon (Ci) at the site of fixation by Rubisco is a key parameter for efficient CO2 fixation in aquatic organisms including the green alga, Chlamydomonas reinhardtii. Chlamydomonas reinhardtii cells, when grown on limiting CO2, have a CO2-concentrating mechanism (CCM) that functions to concentrate CO2 at the site of Rubisco. Proteins thought to be involved in inorganic carbon uptake have been identified and localized to the plasma membrane or chloroplast envelope. However, current CCM models suggest that additional molecular components are involved in Ci uptake. In this study, the gene Cia8 was identified in an insertional mutagenesis screen and characterized. The protein encoded by Cia8 belongs to the sodium bile acid symporter subfamily. Transcript levels for this gene were significantly up-regulated when the cells were grown on low CO2. The cia8 mutant exhibited reduced growth and reduced affinity for Ci when grown in limiting CO2 conditions. Prediction programs localize this protein to the chloroplast. Ci uptake and the photosynthetic rate, particularly at high external pH, were reduced in the mutant. The results are consistent with the model that CIA8 is involved in Ci uptake in C. reinhardtii.
Collapse
Affiliation(s)
- Marylou C Machingura
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA
| | | | - Susan M Laborde
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA
| | | | - Bratati Mukherjee
- ARC Centre of Excellence for Translational Photosynthesis, Division of Plant Sciences, Research School of Biology, Australian National University, Canberra ACT, Australia
| | - Ananya Mukherjee
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA
| | - Steve V Pollock
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA
| | - Britta Förster
- ARC Centre of Excellence for Translational Photosynthesis, Division of Plant Sciences, Research School of Biology, Australian National University, Canberra ACT, Australia
| | - G Dean Price
- ARC Centre of Excellence for Translational Photosynthesis, Division of Plant Sciences, Research School of Biology, Australian National University, Canberra ACT, Australia
| | - James V Moroney
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA
- Correspondence:
| |
Collapse
|