1
|
Fujiwara T, Hirooka S, Yamashita S, Yagisawa F, Miyagishima SY. Development of a rapamycin-inducible protein-knockdown system in the unicellular red alga Cyanidioschyzon merolae. PLANT PHYSIOLOGY 2024; 196:77-94. [PMID: 38833589 PMCID: PMC11376382 DOI: 10.1093/plphys/kiae316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 04/25/2024] [Accepted: 05/14/2024] [Indexed: 06/06/2024]
Abstract
An inducible protein-knockdown system is highly effective for investigating the functions of proteins and mechanisms essential for the survival and growth of organisms. However, this technique is not available in photosynthetic eukaryotes. The unicellular red alga Cyanidioschyzon merolae possesses a very simple cellular and genomic architecture and is genetically tractable but lacks RNA interference machinery. In this study, we developed a protein-knockdown system in this alga. The constitutive system utilizes the destabilizing activity of the FK506-binding protein 12 (FKBP12)-rapamycin-binding (FRB) domain of human target of rapamycin kinase or its derivatives to knock down target proteins. In the inducible system, rapamycin treatment induces the heterodimerization of the human FRB domain fused to the target proteins with the human FKBP fused to S-phase kinase-associated protein 1 or Cullin 1, subunits of the SCF E3 ubiquitin ligase. This results in the rapid degradation of the target proteins through the ubiquitin-proteasome pathway. With this system, we successfully degraded endogenous essential proteins such as the chloroplast division protein dynamin-related protein 5B and E2 transcription factor, a regulator of the G1/S transition, within 2 to 3 h after rapamycin administration, enabling the assessment of resulting phenotypes. This rapamycin-inducible protein-knockdown system contributes to the functional analysis of genes whose disruption leads to lethality.
Collapse
Affiliation(s)
- Takayuki Fujiwara
- Department of Gene Function and Phenomics, National Institute of Genetics, Shizuoka 411-8540, Japan
- Department of Genetics, Graduate University for Advanced Studies (SOKENDAI), Shizuoka 411-8540, Japan
| | - Shunsuke Hirooka
- Department of Gene Function and Phenomics, National Institute of Genetics, Shizuoka 411-8540, Japan
| | - Shota Yamashita
- Department of Gene Function and Phenomics, National Institute of Genetics, Shizuoka 411-8540, Japan
| | - Fumi Yagisawa
- Research Facility Center, University of the Ryukyus, Okinawa 903-0213, Japan
| | - Shin-Ya Miyagishima
- Department of Gene Function and Phenomics, National Institute of Genetics, Shizuoka 411-8540, Japan
- Department of Genetics, Graduate University for Advanced Studies (SOKENDAI), Shizuoka 411-8540, Japan
| |
Collapse
|
2
|
Goold HD, Moseley JL, Lauersen KJ. The synthetic future of algal genomes. CELL GENOMICS 2024; 4:100505. [PMID: 38395701 PMCID: PMC10943592 DOI: 10.1016/j.xgen.2024.100505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 12/18/2023] [Accepted: 01/24/2024] [Indexed: 02/25/2024]
Abstract
Algae are diverse organisms with significant biotechnological potential for resource circularity. Taking inspiration from fermentative microbes, engineering algal genomes holds promise to broadly expand their application ranges. Advances in genome sequencing with improvements in DNA synthesis and delivery techniques are enabling customized molecular tool development to confer advanced traits to algae. Efforts to redesign and rebuild entire genomes to create fit-for-purpose organisms currently being explored in heterotrophic prokaryotes and eukaryotic microbes could also be applied to photosynthetic algae. Future algal genome engineering will enhance yields of native products and permit the expression of complex biochemical pathways to produce novel metabolites from sustainable inputs. We present a historical perspective on advances in engineering algae, discuss the requisite genetic traits to enable algal genome optimization, take inspiration from whole-genome engineering efforts in other microbes for algal systems, and present candidate algal species in the context of these engineering goals.
Collapse
Affiliation(s)
- Hugh D Goold
- New South Wales Department of Primary Industries, Orange, NSW 2800, Australia; ARC Center of Excellence in Synthetic Biology, Macquarie University, Sydney, NSW 2109, Australia; School of Natural Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Jeffrey L Moseley
- California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA; Division of Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Phycoil Biotechnology International, Inc., Fremont, CA 94538, USA
| | - Kyle J Lauersen
- Bioengineering Program, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia.
| |
Collapse
|
3
|
Kobayashi I, Imamura S, Hirota R, Kuroda A, Tanaka K. Expression of bacterial phosphite dehydrogenase confers phosphite availability in a unicellular red alga Cyanidioschyzon merolae. J GEN APPL MICROBIOL 2024; 69:287-291. [PMID: 37587047 DOI: 10.2323/jgam.2023.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/18/2023]
Abstract
Microalgae are promising cell factories for producing value-added products. Large-scale microalgal cultivation suffers from invasion by contaminating microorganisms. Since most contaminating organisms cannot utilize phosphite as a unique phosphorus source, phosphite-utilizing ability may provide a growth advantage against contaminating organisms and solve this problem. Studies showed that microorganisms, typically unable to metabolize phosphite, can utilize phosphite by expressing exogenous phosphite dehydrogenase. Here, we constructed Cyanidioschyzon merolae strains introduced with the phosphite dehydrogenase gene, ptxD, from Ralstonia sp. 4506. The ptxD-introduced strains grew in a phosphite-dependent manner, with the phosphite-related growth rate almost matching that with phosphate as sole phosphorus source.
Collapse
Affiliation(s)
- Ikki Kobayashi
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology
| | - Sousuke Imamura
- Space Environment and Energy Laboratories, Nippon Telegraph and Telephone Corporation
| | - Ryuichi Hirota
- Unit of Biotechnology, Graduate School of Integrated Sciences for Life, Hiroshima University
| | - Akio Kuroda
- Unit of Biotechnology, Graduate School of Integrated Sciences for Life, Hiroshima University
| | - Kan Tanaka
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology
| |
Collapse
|
4
|
Marchetto F, Santaeufemia S, Lebiedzińska-Arciszewska M, Śliwińska MA, Pich M, Kurek E, Naziębło A, Strawski M, Solymosi D, Szklarczyk M, Bulska E, Szymański J, Wierzbicka M, Allahverdiyeva Y, Więckowski MR, Kargul J. Dynamic adaptation of the extremophilic red microalga Cyanidioschyzon merolae to high nickel stress. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2024; 207:108365. [PMID: 38266563 DOI: 10.1016/j.plaphy.2024.108365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 12/23/2023] [Accepted: 01/10/2024] [Indexed: 01/26/2024]
Abstract
The order of Cyanidiales comprises seven acido-thermophilic red microalgal species thriving in hot springs of volcanic origin characterized by extremely low pH, moderately high temperatures and the presence of high concentrations of sulphites and heavy metals that are prohibitive for most other organisms. Little is known about the physiological processes underlying the long-term adaptation of these extremophiles to such hostile environments. Here, we investigated the long-term adaptive responses of a red microalga Cyanidioschyzon merolae, a representative of Cyanidiales, to extremely high nickel concentrations. By the comprehensive physiological, microscopic and elemental analyses we dissected the key physiological processes underlying the long-term adaptation of this model extremophile to high Ni exposure. These include: (i) prevention of significant Ni accumulation inside the cells; (ii) activation of the photoprotective response of non-photochemical quenching; (iii) significant changes of the chloroplast ultrastructure associated with the formation of prolamellar bodies and plastoglobuli together with loosening of the thylakoid membranes; (iv) activation of ROS amelioration machinery; and (v) maintaining the efficient respiratory chain functionality. The dynamically regulated processes identified in this study are discussed in the context of the mechanisms driving the remarkable adaptability of C. merolae to extremely high Ni levels exceeding by several orders of magnitude those found in the natural environment of the microalga. The processes identified in this study provide a solid basis for the future investigation of the specific molecular components and pathways involved in the adaptation of Cyanidiales to the extremely high Ni concentrations.
Collapse
Affiliation(s)
- Francesca Marchetto
- Solar Fuels Laboratory, Center of New Technologies, University of Warsaw, 02-097, Warsaw, Poland
| | - Sergio Santaeufemia
- Solar Fuels Laboratory, Center of New Technologies, University of Warsaw, 02-097, Warsaw, Poland
| | | | - Małgorzata A Śliwińska
- Laboratory of Imaging Tissue Structure and Function, Nencki Institute of Experimental Biology PAS, 02-093, Warsaw, Poland
| | - Magdalena Pich
- Biological and Chemical Research Center, Faculty of Chemistry, University of Warsaw, 02-089, Warsaw, Poland
| | - Eliza Kurek
- Biological and Chemical Research Center, Faculty of Chemistry, University of Warsaw, 02-089, Warsaw, Poland
| | - Aleksandra Naziębło
- Laboratory of Ecotoxicology, Institute of Botany, Faculty of Biology, University of Warsaw, 02-089, Warsaw, Poland
| | - Marcin Strawski
- Laboratory of Electrochemistry, Faculty of Chemistry, University of Warsaw, 02-089, Warsaw, Poland
| | - Daniel Solymosi
- Molecular Plant Biology Unit, Department of Life Technologies, University of Turku, Turku, FI-20014, Finland
| | - Marek Szklarczyk
- Laboratory of Electrochemistry, Faculty of Chemistry, University of Warsaw, 02-089, Warsaw, Poland
| | - Ewa Bulska
- Biological and Chemical Research Center, Faculty of Chemistry, University of Warsaw, 02-089, Warsaw, Poland
| | - Jędrzej Szymański
- Laboratory of Imaging Tissue Structure and Function, Nencki Institute of Experimental Biology PAS, 02-093, Warsaw, Poland
| | - Małgorzata Wierzbicka
- Laboratory of Ecotoxicology, Institute of Botany, Faculty of Biology, University of Warsaw, 02-089, Warsaw, Poland
| | - Yagut Allahverdiyeva
- Molecular Plant Biology Unit, Department of Life Technologies, University of Turku, Turku, FI-20014, Finland
| | - Mariusz R Więckowski
- Laboratory of Mitochondrial Biology and Metabolism, Nencki Institute of Experimental Biology PAS, Warsaw, Poland
| | - Joanna Kargul
- Solar Fuels Laboratory, Center of New Technologies, University of Warsaw, 02-097, Warsaw, Poland.
| |
Collapse
|
5
|
Richtová J, Bazalová O, Horák A, Tomčala A, Gonepogu VG, Oborník M, Doležel D. Circadian rhythms and circadian clock gene homologs of complex alga Chromera velia. FRONTIERS IN PLANT SCIENCE 2023; 14:1226027. [PMID: 38143581 PMCID: PMC10739334 DOI: 10.3389/fpls.2023.1226027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Accepted: 11/20/2023] [Indexed: 12/26/2023]
Abstract
Most organisms on Earth are affected by periodic changes in their environment. The circadian clock is an endogenous device that synchronizes behavior, physiology, or biochemical processes to an approximately 24-hour cycle, allowing organisms to anticipate the periodic changes of day and night. Although circadian clocks are widespread in organisms, the actual molecular components differ remarkably among the clocks of plants, animals, fungi, and prokaryotes. Chromera velia is the closest known photosynthetic relative of apicomplexan parasites. Formation of its motile stage, zoospores, has been described as associated with the light part of the day. We examined the effects on the periodic release of the zoospores under different light conditions and investigated the influence of the spectral composition on zoosporogenesis. We performed a genomic search for homologs of known circadian clock genes. Our results demonstrate the presence of an almost 24-hour free-running cycle of zoosporogenesis. We also identified the blue light spectra as the essential compound for zoosporogenesis. Further, we developed a new and effective method for zoospore separation from the culture and estimated the average motility speed and lifespan of the C. velia zoospores. Our genomic search identified six cryptochrome-like genes, two genes possibly related to Arabidopsis thaliana CCA/LHY, whereas no homolog of an animal, cyanobacterial, or fungal circadian clock gene was found. Our results suggest that C. velia has a functional circadian clock, probably based mainly on a yet undefined mechanism.
Collapse
Affiliation(s)
- Jitka Richtová
- Biology Centre, Academy of Sciences of the Czech Republic, Institute of Parasitology, České Budějovice, Czechia
| | - Olga Bazalová
- Biology Centre, Academy of Sciences of the Czech Republic, Institute of Entomology, České Budějovice, Czechia
| | - Aleš Horák
- Biology Centre, Academy of Sciences of the Czech Republic, Institute of Parasitology, České Budějovice, Czechia
- Department of Molecular Biology, Faculty of Science, University of South Bohemia, České Budějovice, Czechia
| | - Aleš Tomčala
- Faculty of Fisheries and Protection of Waters, University of South Bohemia, Vodňany, Czechia
| | - Vijaya Geetha Gonepogu
- Biology Centre, Academy of Sciences of the Czech Republic, Institute of Parasitology, České Budějovice, Czechia
- Department of Molecular Biology, Faculty of Science, University of South Bohemia, České Budějovice, Czechia
| | - Miroslav Oborník
- Biology Centre, Academy of Sciences of the Czech Republic, Institute of Parasitology, České Budějovice, Czechia
- Department of Molecular Biology, Faculty of Science, University of South Bohemia, České Budějovice, Czechia
| | - David Doležel
- Biology Centre, Academy of Sciences of the Czech Republic, Institute of Entomology, České Budějovice, Czechia
- Department of Molecular Biology, Faculty of Science, University of South Bohemia, České Budějovice, Czechia
| |
Collapse
|
6
|
Seger M, Mammadova F, Villegas-Valencia M, Bastos de Freitas B, Chang C, Isachsen I, Hemstreet H, Abualsaud F, Boring M, Lammers PJ, Lauersen KJ. Engineered ketocarotenoid biosynthesis in the polyextremophilic red microalga Cyanidioschyzon merolae 10D. Metab Eng Commun 2023; 17:e00226. [PMID: 37449053 PMCID: PMC10336515 DOI: 10.1016/j.mec.2023.e00226] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 06/03/2023] [Accepted: 06/08/2023] [Indexed: 07/18/2023] Open
Abstract
The polyextremophilic Cyanidiophyceae are eukaryotic red microalgae with promising biotechnological properties arising from their low pH and elevated temperature requirements which can minimize culture contamination at scale. Cyanidioschyzon merolae 10D is a cell wall deficient species with a fully sequenced genome that is amenable to nuclear transgene integration by targeted homologous recombination. C. merolae maintains a minimal carotenoid profile and here, we sought to determine its capacity for ketocarotenoid accumulation mediated by heterologous expression of a green algal β-carotene ketolase (BKT) and hydroxylase (CHYB). To achieve this, a synthetic transgene expression cassette system was built to integrate and express Chlamydomonas reinhardtii (Cr) sourced enzymes by fusing native C. merolae transcription, translation and chloroplast targeting signals to codon-optimized coding sequences. Chloramphenicol resistance was used to select for the integration of synthetic linear DNAs into a neutral site within the host genome. CrBKT expression caused accumulation of canthaxanthin and adonirubin as major carotenoids while co-expression of CrBKT with CrCHYB generated astaxanthin as the major carotenoid in C. merolae. Unlike green algae and plants, ketocarotenoid accumulation in C. merolae did not reduce total carotenoid contents, but chlorophyll a reduction was observed. Light intensity affected global ratios of all pigments but not individual pigment compositions and phycocyanin contents were not markedly different between parental strain and transformants. Continuous illumination was found to encourage biomass accumulation and all strains could be cultivated in simulated summer conditions from two different extreme desert environments. Our findings present the first example of carotenoid metabolic engineering in a red eukaryotic microalga and open the possibility for use of C. merolae 10D for simultaneous production of phycocyanin and ketocarotenoid pigments.
Collapse
Affiliation(s)
- Mark Seger
- Arizona Center for Algae Technology and Innovation, Arizona State University, 7418 Innovation Way South, Mesa, AZ, 85212, United States
| | - Fakhriyya Mammadova
- Arizona Center for Algae Technology and Innovation, Arizona State University, 7418 Innovation Way South, Mesa, AZ, 85212, United States
| | - Melany Villegas-Valencia
- Bioengineering Program, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Bárbara Bastos de Freitas
- Bioengineering Program, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Clarissa Chang
- Arizona Center for Algae Technology and Innovation, Arizona State University, 7418 Innovation Way South, Mesa, AZ, 85212, United States
| | - Iona Isachsen
- Arizona Center for Algae Technology and Innovation, Arizona State University, 7418 Innovation Way South, Mesa, AZ, 85212, United States
| | - Haley Hemstreet
- Arizona Center for Algae Technology and Innovation, Arizona State University, 7418 Innovation Way South, Mesa, AZ, 85212, United States
| | - Fatimah Abualsaud
- Bioengineering Program, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Malia Boring
- Arizona Center for Algae Technology and Innovation, Arizona State University, 7418 Innovation Way South, Mesa, AZ, 85212, United States
| | - Peter J. Lammers
- Arizona Center for Algae Technology and Innovation, Arizona State University, 7418 Innovation Way South, Mesa, AZ, 85212, United States
| | - Kyle J. Lauersen
- Arizona Center for Algae Technology and Innovation, Arizona State University, 7418 Innovation Way South, Mesa, AZ, 85212, United States
- Bioengineering Program, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Kingdom of Saudi Arabia
| |
Collapse
|
7
|
Borg M, Krueger-Hadfield SA, Destombe C, Collén J, Lipinska A, Coelho SM. Red macroalgae in the genomic era. THE NEW PHYTOLOGIST 2023; 240:471-488. [PMID: 37649301 DOI: 10.1111/nph.19211] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 07/24/2023] [Indexed: 09/01/2023]
Abstract
Rhodophyta (or red algae) are a diverse and species-rich group that forms one of three major lineages in the Archaeplastida, a eukaryotic supergroup whose plastids arose from a single primary endosymbiosis. Red algae are united by several features, such as relatively small intron-poor genomes and a lack of cytoskeletal structures associated with motility like flagella and centrioles, as well as a highly efficient photosynthetic capacity. Multicellular red algae (or macroalgae) are one of the earliest diverging eukaryotic lineages to have evolved complex multicellularity, yet despite their ecological, evolutionary, and commercial importance, they have remained a largely understudied group of organisms. Considering the increasing availability of red algal genome sequences, we present a broad overview of fundamental aspects of red macroalgal biology and posit on how this is expected to accelerate research in many domains of red algal biology in the coming years.
Collapse
Affiliation(s)
- Michael Borg
- Department of Algal Development and Evolution, Max Planck Institute for Biology, 72076, Tübingen, Germany
| | - Stacy A Krueger-Hadfield
- Department of Biology, The University of Alabama at Birmingham, Birmingham, AL, 35294, USA
- Virginia Institute of Marine Science Eastern Shore Laboratory, Wachapreague, VA, 23480, USA
| | - Christophe Destombe
- International Research Laboratory 3614 (IRL3614) - Evolutionary Biology and Ecology of Algae, Centre National de la Recherche Scientifique (CNRS), Sorbonne Université, Pontificia Universidad Católica de Chile, Universidad Austral de Chile, Roscoff, 29680, France
| | - Jonas Collén
- CNRS, Integrative Biology of Marine Models (LBI2M, UMR8227), Station Biologique de Roscoff, Sorbonne Université, Roscoff, 29680, France
| | - Agnieszka Lipinska
- Department of Algal Development and Evolution, Max Planck Institute for Biology, 72076, Tübingen, Germany
| | - Susana M Coelho
- Department of Algal Development and Evolution, Max Planck Institute for Biology, 72076, Tübingen, Germany
| |
Collapse
|
8
|
Villegas-Valencia M, González-Portela RE, de Freitas BB, Al Jahdali A, Romero-Villegas GI, Malibari R, Kapoore RV, Fuentes-Grünewald C, Lauersen KJ. Cultivation of the polyextremophile Cyanidioschyzon merolae 10D during summer conditions on the coast of the Red Sea and its adaptation to hypersaline sea water. Front Microbiol 2023; 14:1157151. [PMID: 37152750 PMCID: PMC10158843 DOI: 10.3389/fmicb.2023.1157151] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 03/28/2023] [Indexed: 05/09/2023] Open
Abstract
The west coast of the Arabian Peninsula borders the Red Sea, a water body which maintains high average temperatures and increased salinity compared to other seas or oceans. This geography has many resources which could be used to support algal biotechnology efforts in bio-resource circularity. However, summer conditions in this region may exceed the temperature tolerance of most currently cultivated microalgae. The Cyanidiophyceae are a class of polyextremophilic red algae that natively inhabit acidic hot springs. C. merolae 10D has recently emerged as an interesting model organism capable of high-cell density cultivation on pure CO2 with optimal growth at elevated temperatures and acidic pH. C. merolae biomass has an interesting macromolecular composition, is protein rich, and contains valuable bio-products like heat-stable phycocyanin, carotenoids, β-glucan, and starch. Here, photobioreactors were used to model C. merolae 10D growth performance in simulated environmental conditions of the mid-Red Sea coast across four seasons, it was then grown at various scales outdoors in Thuwal, Saudi Arabia during the Summer of 2022. We show that C. merolae 10D is amenable to cultivation with industrial-grade nutrient and CO2 inputs outdoors in this location and that its biomass is relatively constant in biochemical composition across culture conditions. We also show the adaptation of C. merolae 10D to high salinity levels of those found in Red Sea waters and conducted further modeled cultivations in nutrient enriched local sea water. It was determined that salt-water adapted C. merolae 10D could be cultivated with reduced nutrient inputs in local conditions. The results presented here indicate this may be a promising alternative species for algal bioprocesses in outdoor conditions in extreme coastal desert summer environments.
Collapse
Affiliation(s)
- Melany Villegas-Valencia
- Bioengineering Program, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Ricardo E. González-Portela
- Development of Algal Biotechnology in Kingdom of Saudi Arabia (DAB-KSA) Project, Beacon Development, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Bárbara Bastos de Freitas
- Bioengineering Program, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Abdulaziz Al Jahdali
- Development of Algal Biotechnology in Kingdom of Saudi Arabia (DAB-KSA) Project, Beacon Development, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Gabriel I. Romero-Villegas
- Development of Algal Biotechnology in Kingdom of Saudi Arabia (DAB-KSA) Project, Beacon Development, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Raghdah Malibari
- Development of Algal Biotechnology in Kingdom of Saudi Arabia (DAB-KSA) Project, Beacon Development, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Rahul Vijay Kapoore
- Development of Algal Biotechnology in Kingdom of Saudi Arabia (DAB-KSA) Project, Beacon Development, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Claudio Fuentes-Grünewald
- Development of Algal Biotechnology in Kingdom of Saudi Arabia (DAB-KSA) Project, Beacon Development, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Kyle J. Lauersen
- Bioengineering Program, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| |
Collapse
|
9
|
Van Etten J, Benites LF, Stephens TG, Yoon HS, Bhattacharya D. Algae obscura: The potential of rare species as model systems. JOURNAL OF PHYCOLOGY 2023; 59:293-300. [PMID: 36764681 DOI: 10.1111/jpy.13321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 01/28/2023] [Indexed: 05/28/2023]
Abstract
Model organism research has provided invaluable knowledge about foundational biological principles. However, most of these studies have focused on species that are in high abundance, easy to cultivate in the lab, and represent only a small fraction of extant biodiversity. Here, we present three examples of rare algae with unusual features that we refer to as "algae obscura." The Cyanidiophyceae (Rhodophyta), Glaucophyta, and Paulinella (rhizarian) lineages have all transitioned out of obscurity to become models for fundamental evolutionary research. Insights have been gained into the prevalence and importance of eukaryotic horizontal gene transfer, early Earth microbial community dynamics, primary plastid endosymbiosis, and the origin of Archaeplastida. By reviewing the research that has come from the exploration of these organisms, we demonstrate that underappreciated algae have the potential to help us formulate, refine, and substantiate core hypotheses and that such organisms should be considered when establishing future model systems.
Collapse
Affiliation(s)
- Julia Van Etten
- Graduate Program in Ecology and Evolution, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA
| | - Luiz Felipe Benites
- Department of Biochemistry and Microbiology, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA
| | - Timothy G Stephens
- Department of Biochemistry and Microbiology, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA
| | - Hwan Su Yoon
- Department of Biological Sciences, Sungkyunkwan University, Suwon, South Korea
| | - Debashish Bhattacharya
- Department of Biochemistry and Microbiology, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA
| |
Collapse
|
10
|
Bowles AMC, Williamson CJ, Williams TA, Lenton TM, Donoghue PCJ. The origin and early evolution of plants. TRENDS IN PLANT SCIENCE 2023; 28:312-329. [PMID: 36328872 DOI: 10.1016/j.tplants.2022.09.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 09/23/2022] [Accepted: 09/30/2022] [Indexed: 06/16/2023]
Abstract
Plant (archaeplastid) evolution has transformed the biosphere, but we are only now beginning to learn how this took place through comparative genomics, phylogenetics, and the fossil record. This has illuminated the phylogeny of Archaeplastida, Viridiplantae, and Streptophyta, and has resolved the evolution of key characters, genes, and genomes - revealing that many key innovations evolved long before the clades with which they have been casually associated. Molecular clock analyses estimate that Streptophyta and Viridiplantae emerged in the late Mesoproterozoic to late Neoproterozoic, whereas Archaeplastida emerged in the late-mid Palaeoproterozoic. Together, these insights inform on the coevolution of plants and the Earth system that transformed ecology and global biogeochemical cycles, increased weathering, and precipitated snowball Earth events, during which they would have been key to oxygen production and net primary productivity (NPP).
Collapse
Affiliation(s)
- Alexander M C Bowles
- School of Geographical Sciences, University of Bristol, University Road, Bristol BS8 1SS, UK; Bristol Palaeobiology Group, School of Biological Sciences and School of Earth Sciences, Life Sciences Building, University of Bristol, Bristol BS8 1TQ, UK.
| | | | - Tom A Williams
- Bristol Palaeobiology Group, School of Biological Sciences and School of Earth Sciences, Life Sciences Building, University of Bristol, Bristol BS8 1TQ, UK
| | - Timothy M Lenton
- Global Systems Institute, University of Exeter, Laver Building, North Park Road, Exeter EX4 4QE, UK
| | - Philip C J Donoghue
- Bristol Palaeobiology Group, School of Biological Sciences and School of Earth Sciences, Life Sciences Building, University of Bristol, Bristol BS8 1TQ, UK.
| |
Collapse
|
11
|
Nishii M, Ito S, Osanai T. Citrate synthase from Cyanidioschyzon merolae exhibits high oxaloacetate and acetyl-CoA catalytic efficiency. PLANT MOLECULAR BIOLOGY 2023; 111:429-438. [PMID: 36884198 DOI: 10.1007/s11103-023-01335-7] [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: 12/15/2022] [Accepted: 01/25/2023] [Indexed: 06/18/2023]
Abstract
Citrate synthase (CS) catalyzes the reaction that produces citrate and CoA from oxaloacetate and acetyl-CoA in the tricarboxylic acid (TCA) cycle. All TCA cycle enzymes are localized to the mitochondria in the model organism, the red alga Cyanidioschyzon merolae. The biochemical properties of CS have been studied in some eukaryotes, but the biochemical properties of CS in algae, including C. merolae, have not been studied. We then performed the biochemical analysis of CS from C. merolae mitochondria (CmCS4). The results showed that the kcat/Km of CmCS4 for oxaloacetate and acetyl-CoA were higher than those of the cyanobacteria, such as Synechocystis sp. PCC 6803, Microcystis aeruginosa PCC 7806 and Anabaena sp. PCC 7120. Monovalent and divalent cations inhibited CmCS4, and in the presence of KCl, the Km of CmCS4 for oxaloacetate and acetyl-CoA was higher in the presence of MgCl2, the Km of CmCS4 for oxaloacetate and acetyl-CoA was higher and kcat lower. However, in the presence of KCl and MgCl2, the kcat/Km of CmCS4 was higher than those of the three cyanobacteria species. The high catalytic efficiency of CmCS4 for oxaloacetate and acetyl-CoA may be a factor in the increased carbon flow into the TCA cycle in C. merolae.
Collapse
Affiliation(s)
- Maki Nishii
- School of Agriculture, Meiji University, 1-1-1, Higashimita, Tama-ku, 214-8571, Kawasaki, Kanagawa, Japan
| | - Shoki Ito
- School of Agriculture, Meiji University, 1-1-1, Higashimita, Tama-ku, 214-8571, Kawasaki, Kanagawa, Japan
| | - Takashi Osanai
- School of Agriculture, Meiji University, 1-1-1, Higashimita, Tama-ku, 214-8571, Kawasaki, Kanagawa, Japan.
| |
Collapse
|
12
|
Van Etten J, Cho CH, Yoon HS, Bhattacharya D. Extremophilic red algae as models for understanding adaptation to hostile environments and the evolution of eukaryotic life on the early earth. Semin Cell Dev Biol 2023; 134:4-13. [PMID: 35339358 DOI: 10.1016/j.semcdb.2022.03.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 02/20/2022] [Accepted: 03/04/2022] [Indexed: 01/08/2023]
Abstract
Extremophiles have always garnered great interest because of their exotic lifestyles and ability to thrive at the physical limits of life. In hot springs environments, the Cyanidiophyceae red algae are the only photosynthetic eukaryotes able to live under extremely low pH (0-5) and relatively high temperature (35ºC to 63ºC). These extremophiles live as biofilms in the springs, inhabit acid soils near the hot springs, and form endolithic populations in the surrounding rocks. Cyanidiophyceae represent a remarkable source of knowledge about the evolution of extremophilic lifestyles and their genomes encode specialized enzymes that have applied uses. Here we review the evolutionary origin, taxonomy, genome biology, industrial applications, and use of Cyanidiophyceae as genetic models. Currently, Cyanidiophyceae comprise a single order (Cyanidiales), three families, four genera, and nine species, including the well-known Cyanidioschyzon merolae and Galdieria sulphuraria. These algae have small, gene-rich genomes that are analogous to those of prokaryotes they live and compete with. There are few spliceosomal introns and evidence exists for horizontal gene transfer as a driver of local adaptation to gain access to external fixed carbon and to extrude toxic metals. Cyanidiophyceae offer a variety of commercial opportunities such as phytoremediation to detoxify contaminated soils or waters and exploitation of their mixotrophic lifestyles to support the efficient production of bioproducts such as phycocyanin and floridosides. In terms of exobiology, Cyanidiophyceae are an ideal model system for understanding the evolutionary effects of foreign gene acquisition and the interactions between different organisms inhabiting the same harsh environment on the early Earth. Finally, we describe ongoing research with C. merolae genetics and summarize the unique insights they offer to the understanding of algal biology and evolution.
Collapse
Affiliation(s)
- Julia Van Etten
- Graduate Program in Ecology and Evolution, Rutgers University, New Brunswick, NJ 08901, USA.
| | - Chung Hyun Cho
- Department of Biological Sciences, Sungkyunkwan University, Suwon 16419, South Korea.
| | - Hwan Su Yoon
- Department of Biological Sciences, Sungkyunkwan University, Suwon 16419, South Korea.
| | - Debashish Bhattacharya
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ 08901, USA.
| |
Collapse
|
13
|
Cho CH, Park SI, Huang TY, Lee Y, Ciniglia C, Yadavalli HC, Yang SW, Bhattacharya D, Yoon HS. Genome-wide signatures of adaptation to extreme environments in red algae. Nat Commun 2023; 14:10. [PMID: 36599855 DOI: 10.1038/s41467-022-35566-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Accepted: 12/09/2022] [Indexed: 01/06/2023] Open
Abstract
The high temperature, acidity, and heavy metal-rich environments associated with hot springs have a major impact on biological processes in resident cells. One group of photosynthetic eukaryotes, the Cyanidiophyceae (Rhodophyta), has successfully thrived in hot springs and associated sites worldwide for more than 1 billion years. Here, we analyze chromosome-level assemblies from three representative Cyanidiophyceae species to study environmental adaptation at the genomic level. We find that subtelomeric gene duplication of functional genes and loss of canonical eukaryotic traits played a major role in environmental adaptation, in addition to horizontal gene transfer events. Shared responses to environmental stress exist in Cyanidiales and Galdieriales, however, most of the adaptive genes (e.g., for arsenic detoxification) evolved independently in these lineages. Our results underline the power of local selection to shape eukaryotic genomes that may face vastly different stresses in adjacent, extreme microhabitats.
Collapse
Affiliation(s)
- Chung Hyun Cho
- Department of Biological Sciences, Sungkyunkwan University, Suwon, 16419, Korea
| | - Seung In Park
- Department of Biological Sciences, Sungkyunkwan University, Suwon, 16419, Korea
| | - Tzu-Yen Huang
- Department of Biological Sciences, Sungkyunkwan University, Suwon, 16419, Korea
| | - Yongsung Lee
- Department of Biological Sciences, Sungkyunkwan University, Suwon, 16419, Korea
| | - Claudia Ciniglia
- Department of Environmental, Biological and Pharmaceutical Science and Technologies, University of Campania Luigi Vanvitelli, Caserta, Italy
| | - Hari Chandana Yadavalli
- Department of Systems Biology, Institute of Life Science and Biotechnology, Yonsei University, Seoul, Korea
| | - Seong Wook Yang
- Department of Systems Biology, Institute of Life Science and Biotechnology, Yonsei University, Seoul, Korea
| | | | - Hwan Su Yoon
- Department of Biological Sciences, Sungkyunkwan University, Suwon, 16419, Korea.
| |
Collapse
|
14
|
Mallén-Ponce MJ, Pérez-Pérez ME, Crespo JL. Deciphering the function and evolution of the target of rapamycin signaling pathway in microalgae. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:6993-7005. [PMID: 35710309 PMCID: PMC9664231 DOI: 10.1093/jxb/erac264] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 06/16/2022] [Indexed: 06/15/2023]
Abstract
Microalgae constitute a highly diverse group of photosynthetic microorganisms that are widely distributed on Earth. The rich diversity of microalgae arose from endosymbiotic events that took place early in the evolution of eukaryotes and gave rise to multiple lineages including green algae, the ancestors of land plants. In addition to their fundamental role as the primary source of marine and freshwater food chains, microalgae are essential producers of oxygen on the planet and a major biotechnological target for sustainable biofuel production and CO2 mitigation. Microalgae integrate light and nutrient signals to regulate cell growth. Recent studies identified the target of rapamycin (TOR) kinase as a central regulator of cell growth and a nutrient sensor in microalgae. TOR promotes protein synthesis and regulates processes that are induced under nutrient stress such as autophagy and the accumulation of triacylglycerol and starch. A detailed analysis of representative genomes from the entire microalgal lineage revealed that the highly conserved central components of the TOR pathway are likely to have been present in the last eukaryotic common ancestor, and the loss of specific TOR signaling elements at an early stage in the evolution of microalgae. Here we examine the evolutionary conservation of TOR signaling components in diverse microalgae and discuss recent progress of this signaling pathway in these organisms.
Collapse
Affiliation(s)
- Manuel J Mallén-Ponce
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas-Universidad de Sevilla, Sevilla, Spain
| | - María Esther Pérez-Pérez
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas-Universidad de Sevilla, Sevilla, Spain
| | | |
Collapse
|
15
|
Life cycle and functional genomics of the unicellular red alga Galdieria for elucidating algal and plant evolution and industrial use. Proc Natl Acad Sci U S A 2022; 119:e2210665119. [PMID: 36194630 PMCID: PMC9565259 DOI: 10.1073/pnas.2210665119] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Sexual reproduction has not been observed in unicellular red algae and Glaucophyceae, early branching groups in Archaeplastida, in which red algae and Viridiplantae independently evolved multicellular sexual life cycles. The finding of sexual reproduction in the unicellular red alga Galdieria provides information on the missing link of life cycle evolution in Archaeplastida. In addition, the metabolic plasticity, the polyextremophilic features, a relatively small genome, transcriptome data for the diploid and haploid, and the genetic modification tools developed here provide a useful platform for understanding the evolution of Archaeplastida, photosynthesis, metabolism, and environmental adaptation. For biotechnological use of the information and tools of Galdieria, the newly found cell wall–less haploid makes cell disruption less energy/cost intensive than the cell-walled diploid. Sexual reproduction is widespread in eukaryotes; however, only asexual reproduction has been observed in unicellular red algae, including Galdieria, which branched early in Archaeplastida. Galdieria possesses a small genome; it is polyextremophile, grows either photoautotrophically, mixotrophically, or heterotrophically, and is being developed as an industrial source of vitamins and pigments because of its high biomass productivity. Here, we show that Galdieria exhibits a sexual life cycle, alternating between cell-walled diploid and cell wall–less haploid, and that both phases can proliferate asexually. The haploid can move over surfaces and undergo self-diploidization or generate heterozygous diploids through mating. Further, we prepared the whole genome and a comparative transcriptome dataset between the diploid and haploid and developed genetic tools for the stable gene expression, gene disruption, and selectable marker recycling system using the cell wall–less haploid. The BELL/KNOX and MADS-box transcription factors, which function in haploid-to-diploid transition and development in plants, are specifically expressed in the haploid and diploid, respectively, and are involved in the haploid-to-diploid transition in Galdieria, providing information on the missing link of the sexual life cycle evolution in Archaeplastida. Four actin genes are differently involved in motility of the haploid and cytokinesis in the diploid, both of which are myosin independent and likely reflect ancestral roles of actin. We have also generated photosynthesis-deficient mutants, such as blue-colored cells, which were depleted in chlorophyll and carotenoids, for industrial pigment production. These features of Galdieria facilitate the understanding of the evolution of algae and plants and the industrial use of microalgae.
Collapse
|
16
|
Stadnichuk IN, Tropin IV. Cyanidiales as Polyextreme Eukaryotes. BIOCHEMISTRY. BIOKHIMIIA 2022; 87:472-487. [PMID: 35790381 DOI: 10.1134/s000629792205008x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 03/28/2022] [Accepted: 04/24/2022] [Indexed: 06/15/2023]
Abstract
Cyanidiales were named enigmatic microalgae due to their unique polyextreme properties, considered for a very long time unattainable for eukaryotes. Cyanidiales mainly inhabit hot sulfuric springs with high acidity (pH 0-4), temperatures up to 56°C, and ability to survive in the presence of dissolved heavy metals. Owing to the minimal for eukaryotes genome size, Cyanidiales have become one of the most important research objects in plant cell physiology, biochemistry, molecular biology, phylogenomics, and evolutionary biology. They play an important role in studying many aspects of oxygenic photosynthesis and chloroplasts origin. The ability to survive in stressful habitats and the corresponding metabolic pathways were acquired by Cyanidiales from archaea and bacteria via horizontal gene transfer (HGT). Thus, the possibility of gene transfer from prokaryotes to eukaryotes was discovered, which was a new step in understanding of the origin of eukaryotic cell.
Collapse
Affiliation(s)
- Igor N Stadnichuk
- Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Moscow, 127726, Russia.
| | - Ivan V Tropin
- Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| |
Collapse
|
17
|
Kselíková V, Singh A, Bialevich V, Čížková M, Bišová K. Improving microalgae for biotechnology - From genetics to synthetic biology - Moving forward but not there yet. Biotechnol Adv 2021; 58:107885. [PMID: 34906670 DOI: 10.1016/j.biotechadv.2021.107885] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 11/28/2021] [Accepted: 12/07/2021] [Indexed: 12/28/2022]
Abstract
Microalgae are a diverse group of photosynthetic organisms that can be exploited for the production of different compounds, ranging from crude biomass and biofuels to high value-added biochemicals and synthetic proteins. Traditionally, algal biotechnology relies on bioprospecting to identify new highly productive strains and more recently, on forward genetics to further enhance productivity. However, it has become clear that further improvements in algal productivity for biotechnology is impossible without combining traditional tools with the arising molecular genetics toolkit. We review recent advantages in developing high throughput screening methods, preparing genome-wide mutant libraries, and establishing genome editing techniques. We discuss how algae can be improved in terms of photosynthetic efficiency, biofuel and high value-added compound production. Finally, we critically evaluate developments over recent years and explore future potential in the field.
Collapse
Affiliation(s)
- Veronika Kselíková
- Institute of Microbiology of the Czech Academy of Sciences, Centre Algatech, Laboratory of Cell Cycles of Algae, 379 81 Třeboň, Czech Republic; Faculty of Science, University of South Bohemia, 37005 České Budějovice, Czech Republic
| | - Anjali Singh
- Institute of Microbiology of the Czech Academy of Sciences, Centre Algatech, Laboratory of Cell Cycles of Algae, 379 81 Třeboň, Czech Republic
| | - Vitali Bialevich
- Institute of Microbiology of the Czech Academy of Sciences, Centre Algatech, Laboratory of Cell Cycles of Algae, 379 81 Třeboň, Czech Republic
| | - Mária Čížková
- Institute of Microbiology of the Czech Academy of Sciences, Centre Algatech, Laboratory of Cell Cycles of Algae, 379 81 Třeboň, Czech Republic
| | - Kateřina Bišová
- Institute of Microbiology of the Czech Academy of Sciences, Centre Algatech, Laboratory of Cell Cycles of Algae, 379 81 Třeboň, Czech Republic.
| |
Collapse
|
18
|
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
|