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Muramatsu S, Atsuji K, Yamada K, Ozasa K, Suzuki H, Takeuchi T, Hashimoto-Marukawa Y, Kazama Y, Abe T, Suzuki K, Iwata O. Isolation and characterization of a motility-defective mutant of Euglena gracilis. PeerJ 2020; 8:e10002. [PMID: 33062431 PMCID: PMC7528813 DOI: 10.7717/peerj.10002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 08/30/2020] [Indexed: 12/15/2022] Open
Abstract
Euglena gracilis is a green photosynthetic microalga that swims using its flagellum. This species has been used as a model organism for over half a century to study its metabolism and the mechanisms of its behavior. The development of mass-cultivation technology has led to E. gracilis application as a feedstock in various products such as foods. Therefore, breeding of E. gracilis has been attempted to improve the productivity of this feedstock for potential industrial applications. For this purpose, a characteristic that preserves the microalgal energy e.g., reduces motility, should be added to the cultivars. The objective of this study was to verify our hypothesis that E. gracilis locomotion-defective mutants are suitable for industrial applications because they save the energy required for locomotion. To test this hypothesis, we screened for E. gracilis mutants from Fe-ion-irradiated cell suspensions and established a mutant strain,M 3 - ZFeL, which shows defects in flagellum formation and locomotion. The mutant strain exhibits a growth rate comparable to that of the wild type when cultured under autotrophic conditions, but had a slightly slower growth under heterotrophic conditions. It also stores 1.6 times the amount of paramylon, a crystal of β-1,3-glucan, under autotrophic culture conditions, and shows a faster sedimentation compared with that of the wild type, because of the deficiency in mobility and probably the high amount of paramylon accumulation. Such characteristics make E. gracilis mutant cells suitable for cost-effective mass cultivation and harvesting.
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Affiliation(s)
- Shuki Muramatsu
- Department of Health Science, Showa Women's University, Tokyo, Japan
- euglena Co., Ltd., Tokyo, Japan
| | - Kohei Atsuji
- euglena Co., Ltd., Tokyo, Japan
- Baton Zone Program, RIKEN, Saitama, Japan
| | - Koji Yamada
- euglena Co., Ltd., Tokyo, Japan
- Baton Zone Program, RIKEN, Saitama, Japan
| | - Kazunari Ozasa
- Bioengineering Laboratory, Cluster for Pioneering Research, RIKEN, Saitama, Japan
| | | | | | | | - Yusuke Kazama
- RIKEN Nishina Center, Saitama, Japan
- Faculty of Bioscience and Biotechnology, Fukui Prefectural University, Fukui, Japan
| | | | - Kengo Suzuki
- euglena Co., Ltd., Tokyo, Japan
- Baton Zone Program, RIKEN, Saitama, Japan
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Viswanadha R, Hunter EL, Yamamoto R, Wirschell M, Alford LM, Dutcher SK, Sale WS. The ciliary inner dynein arm, I1 dynein, is assembled in the cytoplasm and transported by IFT before axonemal docking. Cytoskeleton (Hoboken) 2014; 71:573-86. [PMID: 25252184 DOI: 10.1002/cm.21192] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 09/11/2014] [Accepted: 09/15/2014] [Indexed: 01/11/2023]
Abstract
To determine mechanisms of assembly of ciliary dyneins, we focused on the Chlamydomonas inner dynein arm, I1 dynein, also known as dynein f. I1 dynein assembles in the cytoplasm as a 20S complex similar to the 20S I1 dynein complex isolated from the axoneme. The intermediate chain subunit, IC140 (IDA7), and heavy chains (IDA1, IDA2) are required for 20S I1 dynein preassembly in the cytoplasm. Unlike I1 dynein derived from the axoneme, the cytoplasmic 20S I1 complex will not rebind I1-deficient axonemes in vitro. To test the hypothesis that I1 dynein is transported to the distal tip of the cilia for assembly in the axoneme, we performed cytoplasmic complementation in dikaryons formed between wild-type and I1 dynein mutant cells. Rescue of I1 dynein assembly in mutant cilia occurred first at the distal tip and then proceeded toward the proximal axoneme. Notably, in contrast to other combinations, I1 dynein assembly was significantly delayed in dikaryons formed between ida7 and ida3. Furthermore, rescue of I1 dynein assembly required new protein synthesis in the ida7 × ida3 dikaryons. On the basis of the additional observations, we postulate that IDA3 is required for 20S I1 dynein transport. Cytoplasmic complementation in dikaryons using the conditional kinesin-2 mutant, fla10-1 revealed that transport of I1 dynein is dependent on kinesin-2 activity. Thus, I1 dynein complex assembly depends upon IFT for transport to the ciliary distal tip prior to docking in the axoneme.
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Affiliation(s)
- Rasagnya Viswanadha
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia
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Fujita S, Matsuo T, Ishiura M, Kikkawa M. High-throughput phenotyping of chlamydomonas swimming mutants based on nanoscale video analysis. Biophys J 2014; 107:336-345. [PMID: 25028875 PMCID: PMC4104059 DOI: 10.1016/j.bpj.2014.05.033] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 05/24/2014] [Accepted: 05/29/2014] [Indexed: 11/18/2022] Open
Abstract
Studies on biflagellated algae Chlamydomonas reinhardtii mutants have resulted in significant contributions to our understanding of the functions of cilia/flagella components. However, visual inspection conducted under a microscope to screen and classify Chlamydomonas swimming requires considerable time, effort, and experience. In addition, it is likely that identification of mutants by this screening is biased toward individual cells with severe swimming defects, and mutants that swim slightly more slowly than wild-type cells may be missed by these screening methods. To systematically screen Chlamydomonas swimming mutants, we have here developed the cell-locating-with-nanoscale-accuracy (CLONA) method to identify the cell position to within 10-nm precision through the analysis of high-speed video images. Instead of analyzing the shape of the flagella, which is not always visible in images, we determine the position of Chlamydomonas cell bodies by determining the cross-correlation between a reference image and the image of the cell. From these positions, various parameters related to swimming, such as velocity and beat frequency, can be accurately estimated for each beat cycle. In the examination of wild-type and seven dynein arm mutants of Chlamydomonas, we found characteristic clustering on scatter plots of beat frequency versus swimming velocity. Using the CLONA method, we have screened 38 Chlamydomonas strains and detected believed-novel motility-deficient mutants that would be missed by visual screening. This CLONA method can automate the screening for mutants of Chlamydomonas and contribute to the elucidation of the functions of motility-associated proteins.
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Affiliation(s)
- Shohei Fujita
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Takuya Matsuo
- Center for Gene Research, Nagoya University, Nagoya, Japan
| | | | - Masahide Kikkawa
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
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Koutoulis A, Pazour GJ, Wilkerson CG, Inaba K, Sheng H, Takada S, Witman GB. The Chlamydomonas reinhardtii ODA3 gene encodes a protein of the outer dynein arm docking complex. J Cell Biol 1997; 137:1069-80. [PMID: 9166407 PMCID: PMC2136212 DOI: 10.1083/jcb.137.5.1069] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/1997] [Revised: 04/04/1997] [Indexed: 02/04/2023] Open
Abstract
We have used an insertional mutagenesis/ gene tagging technique to generate new Chlamydomonas reinhardtii mutants that are defective in assembly of the uter ynein rm. Among 39 insertional oda mutants characterized, two are alleles of the previously uncloned ODA3 gene, one is an allele of the uncloned ODA10 gene, and one represents a novel ODA gene (termed ODA12). ODA3 is of particular interest because it is essential for assembly of both the outer dynein arm and the outer dynein arm docking complex (ODA-DC) onto flagellar doublet microtubules (Takada, S., and R. Kamiya. 1994. J. Cell Biol. 126:737- 745). Beginning with the inserted DNA as a tag, the ODA3 gene and a full-length cDNA were cloned. The cloned gene rescues the phenotype of oda3 mutants. The cDNA sequence predicts a novel 83. 4-kD protein with extensive coiled-coil domains. The ODA-DC contains three polypeptides; direct amino acid sequencing indicates that the largest of these polypeptides corresponds to ODA3. This protein is likely to have an important role in the precise positioning of the outer dynein arms on the flagellar axoneme.
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Affiliation(s)
- A Koutoulis
- Department of Plant Science, The University of Tasmania, Hobart TAS 7001 Australia
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Wilkerson CG, King SM, Koutoulis A, Pazour GJ, Witman GB. The 78,000 M(r) intermediate chain of Chlamydomonas outer arm dynein isa WD-repeat protein required for arm assembly. J Biophys Biochem Cytol 1995; 129:169-78. [PMID: 7698982 PMCID: PMC2120364 DOI: 10.1083/jcb.129.1.169] [Citation(s) in RCA: 143] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
We have isolated and sequenced a full-length cDNA clone encoding the 78,000 Mr intermediate chain (IC78) of the Chlamydomonas outer arm dynein. This protein previously was shown to be located at the base of the solubilized dynein particle and to interact with alpha tubulin in situ, suggesting that it may be involved in binding the outer arm to the doublet microtubule. The sequence predicts a polypeptide of 683 amino acids having a mass of 76.5 kD. Sequence comparison indicates that IC78 is homologous to the 69,000 M(r) intermediate chain (IC69) of Chlamydomonas outer arm dynein and to the 74,000 M(r) intermediate chain (IC74) of cytoplasmic dynein. The similarity between the chains is greatest in their COOH-terminal halves; the NH(2)-terminal halves are highly divergent. The COOH-terminal half of IC78 contains six short imperfect repeats, termed WD repeats, that are thought to be involved in protein-protein interactions. Although not previously reported, these repeated elements also are present in IC69 and IC74. Using the IC78 cDNA as a probe, we screened a group of slow-swimming insertional mutants and identified one which has a large insertion in the IC78 gene and seven in which the IC78 gene is completely deleted. Electron microscopy of three of these IC78 mutants revealed that each is missing the outer arm, indicating that IC78 is essential for arm assembly or attachment to the outer doublet. Restriction fragment length polymorphism mapping places the IC78 gene on the left arm of chromosome XII/XIII, at or near the mutation oda9, which also causes loss of the outer arm. Mutants with defects in the IC78 gene do not complement the oda9 mutation in stable diploids, strongly suggesting that ODA9 is the structural gene for IC78.
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Affiliation(s)
- C G Wilkerson
- Worcester Foundation for Experimental Biology, Shrewsbury, Massachusetts 01545
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Kamiya R. Strategies for isolation of flagellar motility and assembly mutants in Chlamydomonas. Methods Cell Biol 1995; 47:541-4. [PMID: 7476542 DOI: 10.1016/s0091-679x(08)60858-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- R Kamiya
- Zoological Institute, Graduate School of Science, University of Tokyo, Japan
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