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Lv Y, Han F, Liu M, Zhang T, Cui G, Wang J, Yang Y, Yang YG, Yang W. Characteristics of N 6-methyladenosine Modification During Sexual Reproduction of Chlamydomonas reinhardtii. GENOMICS, PROTEOMICS & BIOINFORMATICS 2023; 21:756-768. [PMID: 35550876 PMCID: PMC10787120 DOI: 10.1016/j.gpb.2022.04.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 04/12/2022] [Accepted: 04/24/2022] [Indexed: 06/15/2023]
Abstract
The unicellular green alga Chlamydomonas reinhardtii (hereafter Chlamydomonas) possesses both plant and animal attributes, and it is an ideal model organism for studying fundamental processes such as photosynthesis, sexual reproduction, and life cycle. N6-methyladenosine (m6A) is the most prevalent mRNA modification, and it plays important roles during sexual reproduction in animals and plants. However, the pattern and function of m6A modification during the sexual reproduction of Chlamydomonas remain unknown. Here, we performed transcriptome and methylated RNA immunoprecipitation sequencing (MeRIP-seq) analyses on six samples from different stages during sexual reproduction of the Chlamydomonas life cycle. The results show that m6A modification frequently occurs at the main motif of DRAC (D = G/A/U, R = A/G) in Chlamydomonas mRNAs. Moreover, m6A peaks in Chlamydomonas mRNAs are mainly enriched in the 3' untranslated regions (3'UTRs) and negatively correlated with the abundance of transcripts at each stage. In particular, there is a significant negative correlation between the expression levels and the m6A levels of genes involved in the microtubule-associated pathway, indicating that m6A modification influences the sexual reproduction and the life cycle of Chlamydomonas by regulating microtubule-based movement. In summary, our findings are the first to demonstrate the distribution and the functions of m6A modification in Chlamydomonas mRNAs and provide new evolutionary insights into m6A modification in the process of sexual reproduction in other plant organisms.
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Affiliation(s)
- Ying Lv
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; China National Botanical Garden, Beijing 100093, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Fei Han
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; China National Botanical Garden, Beijing 100093, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mengxia Liu
- CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China; Sino-Danish College, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ting Zhang
- CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China
| | - Guanshen Cui
- CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China
| | - Jiaojiao Wang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; China National Botanical Garden, Beijing 100093, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100049, China; Sino-Danish College, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ying Yang
- CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China; Sino-Danish College, University of Chinese Academy of Sciences, Beijing 100049, China; Institute of Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China
| | - Yun-Gui Yang
- CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China; Sino-Danish College, University of Chinese Academy of Sciences, Beijing 100049, China; Institute of Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China
| | - Wenqiang Yang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; China National Botanical Garden, Beijing 100093, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100049, China; Sino-Danish College, University of Chinese Academy of Sciences, Beijing 100049, China; Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing 100093, China.
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2
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Sheng M, Ma X, Wang J, Xue T, Li Z, Cao Y, Yu X, Zhang X, Wang Y, Xu W, Su Z. KNOX II transcription factor HOS59 functions in regulating rice grain size. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 110:863-880. [PMID: 35167131 DOI: 10.1111/tpj.15709] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Revised: 01/30/2022] [Accepted: 02/10/2022] [Indexed: 06/14/2023]
Abstract
Plant Knotted1-like homeobox (KNOX) genes encode homeodomain-containing transcription factors. In rice (Oryza sativa L.), little is known about the downstream target genes of KNOX Class II subfamily proteins. Here we generated chromatin immunoprecipitation (ChIP)-sequencing datasets for HOS59, a member of the rice KNOX Class II subfamily, and characterized the genome-wide binding sites of HOS59. We conducted trait ontology (TO) analysis of 9705 identified downstream target genes, and found that multiple TO terms are related to plant structure morphology and stress traits. ChIP-quantitative PCR (qPCR) was conducted to validate some key target genes. Meanwhile, our IP-MS datasets showed that HOS59 was closely associated with BELL family proteins, some grain size regulators (OsSPL13, OsSPL16, OsSPL18, SLG, etc.), and some epigenetic modification factors such as OsAGO4α and OsAGO4β, proteins involved in small interfering RNA-mediated gene silencing. Furthermore, we employed CRISPR/Cas9 editing and transgenic approaches to generate hos59 mutants and overexpression lines, respectively. Compared with wild-type plants, the hos59 mutants have longer grains and increased glume cell length, a loose plant architecture, and drooping leaves, while the overexpression lines showed smaller grain size, erect leaves, and lower plant height. The qRT-PCR results showed that mutation of the HOS59 gene led to upregulation of some grain size-related genes such as OsSPL13, OsSPL18, and PGL2. In summary, our results indicate that HOS59 may be a repressor of the downstream target genes, negatively regulating glume cell length, rice grain size, plant architecture, etc. The identified downstream target genes and possible interaction proteins of HOS59 improve our understanding of the KNOX regulatory networks.
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Affiliation(s)
- Minghao Sheng
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Xuelian Ma
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Jiyao Wang
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Tianxi Xue
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Zhongqiu Li
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Yaxin Cao
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Xinyue Yu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Xinyi Zhang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Yonghong Wang
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Wenying Xu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Zhen Su
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
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3
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Hisanaga T, Fujimoto S, Cui Y, Sato K, Sano R, Yamaoka S, Kohchi T, Berger F, Nakajima K. Deep evolutionary origin of gamete-directed zygote activation by KNOX/BELL transcription factors in green plants. eLife 2021; 10:57090. [PMID: 34579806 PMCID: PMC8478417 DOI: 10.7554/elife.57090] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 09/02/2021] [Indexed: 02/03/2023] Open
Abstract
KNOX and BELL transcription factors regulate distinct steps of diploid development in plants. In the green alga Chlamydomonas reinhardtii, KNOX and BELL proteins are inherited by gametes of the opposite mating types and heterodimerize in zygotes to activate diploid development. By contrast, in land plants such as Physcomitrium patens and Arabidopsis thaliana, KNOX and BELL proteins function in sporophyte and spore formation, meristem maintenance and organogenesis during the later stages of diploid development. However, whether the contrasting functions of KNOX and BELL were acquired independently in algae and land plants is currently unknown. Here, we show that in the basal land plant species Marchantia polymorpha, gamete-expressed KNOX and BELL are required to initiate zygotic development by promoting nuclear fusion in a manner strikingly similar to that in C. reinhardtii. Our results indicate that zygote activation is the ancestral role of KNOX/BELL transcription factors, which shifted toward meristem maintenance as land plants evolved.
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Affiliation(s)
- Tetsuya Hisanaga
- Graduate School of Science and Technology, Nara Institute of Science and Technology, Nara, Japan.,Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna Biocenter, Vienna, Austria
| | - Shota Fujimoto
- Graduate School of Science and Technology, Nara Institute of Science and Technology, Nara, Japan
| | - Yihui Cui
- Graduate School of Science and Technology, Nara Institute of Science and Technology, Nara, Japan
| | - Katsutoshi Sato
- Graduate School of Science and Technology, Nara Institute of Science and Technology, Nara, Japan
| | - Ryosuke Sano
- Graduate School of Science and Technology, Nara Institute of Science and Technology, Nara, Japan
| | - Shohei Yamaoka
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Takayuki Kohchi
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Frédéric Berger
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna Biocenter, Vienna, Austria
| | - Keiji Nakajima
- Graduate School of Science and Technology, Nara Institute of Science and Technology, Nara, Japan
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4
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Dierschke T, Flores-Sandoval E, Rast-Somssich MI, Althoff F, Zachgo S, Bowman JL. Gamete expression of TALE class HD genes activates the diploid sporophyte program in Marchantia polymorpha. eLife 2021; 10:57088. [PMID: 34533136 PMCID: PMC8476127 DOI: 10.7554/elife.57088] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 09/15/2021] [Indexed: 12/16/2022] Open
Abstract
Eukaryotic life cycles alternate between haploid and diploid phases and in phylogenetically diverse unicellular eukaryotes, expression of paralogous homeodomain genes in gametes primes the haploid-to-diploid transition. In the unicellular chlorophyte alga Chlamydomonas, KNOX and BELL TALE-homeodomain genes mediate this transition. We demonstrate that in the liverwort Marchantia polymorpha, paternal (sperm) expression of three of five phylogenetically diverse BELL genes, MpBELL234, and maternal (egg) expression of both MpKNOX1 and MpBELL34 mediate the haploid-to-diploid transition. Loss-of-function alleles of MpKNOX1 result in zygotic arrest, whereas a loss of either maternal or paternal MpBELL234 results in variable zygotic and early embryonic arrest. Expression of MpKNOX1 and MpBELL34 during diploid sporophyte development is consistent with a later role for these genes in patterning the sporophyte. These results indicate that the ancestral mechanism to activate diploid gene expression was retained in early diverging land plants and subsequently co-opted during evolution of the diploid sporophyte body.
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Affiliation(s)
- Tom Dierschke
- School of Biological Sciences, Monash University, Melbourne, Australia.,Botany Department, University of Osnabrück, Osnabrück, Germany
| | | | | | - Felix Althoff
- Botany Department, University of Osnabrück, Osnabrück, Germany
| | - Sabine Zachgo
- Botany Department, University of Osnabrück, Osnabrück, Germany
| | - John L Bowman
- School of Biological Sciences, Monash University, Melbourne, Australia
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5
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Evolution of an assembly factor-based subunit contributed to a novel NDH-PSI supercomplex formation in chloroplasts. Nat Commun 2021; 12:3685. [PMID: 34140516 PMCID: PMC8211685 DOI: 10.1038/s41467-021-24065-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 05/27/2021] [Indexed: 11/09/2022] Open
Abstract
Chloroplast NADH dehydrogenase-like (NDH) complex is structurally related to mitochondrial Complex I and forms a supercomplex with two copies of Photosystem I (the NDH-PSI supercomplex) via linker proteins Lhca5 and Lhca6. The latter was acquired relatively recently in a common ancestor of angiosperms. Here we show that NDH-dependent Cyclic Electron Flow 5 (NDF5) is an NDH assembly factor in Arabidopsis. NDF5 initiates the assembly of NDH subunits (PnsB2 and PnsB3) and Lhca6, suggesting that they form a contact site with Lhca6. Our analysis of the NDF5 ortholog in Physcomitrella and angiosperm genomes reveals the subunit PnsB2 to be newly acquired via tandem gene duplication of NDF5 at some point in the evolution of angiosperms. Another Lhca6 contact subunit, PnsB3, has evolved from a protein unrelated to NDH. The structure of the largest photosynthetic electron transport chain complex has become more complicated by acquiring novel subunits and supercomplex formation with PSI. The chloroplast NDH complex interacts with Photosystem I to form the NDH-PSI supercomplex. Here the authors show that Arabidopsis NDF5 shares a common ancestor with the NDH subunit PnsB2 and acts as an NDH assembly factor initiating the assembly of PnsB2 and the evolutionarily distinct PnsB3.
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Di Nardo AA, Joliot A, Prochiantz A. Homeoprotein transduction in neurodevelopment and physiopathology. SCIENCE ADVANCES 2020; 6:6/44/eabc6374. [PMID: 33115744 PMCID: PMC7608782 DOI: 10.1126/sciadv.abc6374] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 09/11/2020] [Indexed: 05/28/2023]
Abstract
Homeoproteins were originally identified for embryonic cell-autonomous transcription activity, but they also have non-cell-autonomous activity owing to transfer between cells. This Review discusses transfer mechanisms and focuses on some established functions, such as neurodevelopmental regulation of axon guidance, and postnatal critical periods of brain plasticity that affect sensory processing and cognition. Homeoproteins are present across all eukaryotes, and intercellular transfer occurs in plants and animals. Proposed functions have evolutionary relevance, such as morphogenetic activity and sexual exchange during the mating of unicellular eukaryotes, while others have physiopathological relevance, such as regulation of mood and cognition by influencing brain compartmentalization, connectivity, and plasticity. There are more than 250 known homeoproteins with conserved transfer domains, suggesting that this is a common mode of signal transduction but with many undiscovered functions.
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Affiliation(s)
- Ariel A Di Nardo
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL University, Labex MemoLife, 75005 Paris, France.
| | - Alain Joliot
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL University, Labex MemoLife, 75005 Paris, France
| | - Alain Prochiantz
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050, PSL University, Labex MemoLife, 75005 Paris, France.
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7
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Step-wise elimination of α-mitochondrial nucleoids and mitochondrial structure as a basis for the strict uniparental inheritance in Cryptococcus neoformans. Sci Rep 2020; 10:2468. [PMID: 32051468 PMCID: PMC7016115 DOI: 10.1038/s41598-020-59277-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Accepted: 01/27/2020] [Indexed: 01/24/2023] Open
Abstract
In most sexual eukaryotes, mitochondrial (mt) DNA is uniparentally inherited, although the detailed mechanisms underlying this phenomenon remain controversial. The most widely accepted explanations include the autophagic elimination of paternal mitochondria in the fertilized eggs and the active degradation of paternal mitochondrial DNA. To decode the precise program for the uniparental inheritance, we focused on Cryptococcus neoformans as a model system, in which mtDNA is inherited only from the a-parent, although gametes of a- and α-cells are of equal size and contribute equal amounts of mtDNA to the zygote. In this research, the process of preferential elimination of the mitochondria contributed by the α-parent (α-mitochondria) was studied by fluorescence microscopy and single cell analysis using optical tweezers, which revealed that α-mitochondria are preferentially reduced by the following three steps: (1) preferential reduction of α-mitochondrial (mt) nucleoids and α-mtDNA, (2) degradation of the α-mitochondrial structure and (3) proliferation of remaining mt nucleoids during the zygote development. Furthermore, AUTOPHAGY RELATED GENE (ATG) 8 and the gene encoding mitochondrial endonuclease G (NUC1) were disrupted, and the effects of their disruption on the uniparental inheritance were scrutinized. Disruption of ATG8 (ATG7) and NUC1 did not have severe effects on the uniparental inheritance, but microscopic examination revealed that α-mitochondria lacking mt nucleoids persisted in Δatg8 zygotes, indicating that autophagy is not critical for the uniparental inheritance per se but is responsible for the clearance of mitochondrial structures after the reduction of α-mt nucleoids.
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8
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Bloomfield G. The molecular foundations of zygosis. Cell Mol Life Sci 2020; 77:323-330. [PMID: 31203379 PMCID: PMC11105095 DOI: 10.1007/s00018-019-03187-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 05/27/2019] [Accepted: 06/06/2019] [Indexed: 10/26/2022]
Abstract
Zygosis is the generation of new biological individuals by the sexual fusion of gamete cells. Our current understanding of eukaryotic phylogeny indicates that sex is ancestral to all extant eukaryotes. Although sexual development is extremely diverse, common molecular elements have been retained. HAP2-GCS1, a protein that promotes the fusion of gamete cell membranes that is related in structure to certain viral fusogens, is conserved in many eukaryotic lineages, even though gametes vary considerably in form and behaviour between species. Similarly, although zygotes have dramatically different forms and fates in different organisms, diverse eukaryotes share a common developmental programme in which homeodomain-containing transcription factors play a central role. These common mechanistic elements suggest possible common evolutionary histories that, if correct, would have profound implications for our understanding of eukaryogenesis.
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Mignerot L, Nagasato C, Peters AF, Perrineau MM, Scornet D, Pontheaux F, Djema W, Badis Y, Motomura T, Coelho SM, Cock JM. Unusual Patterns of Mitochondrial Inheritance in the Brown Alga Ectocarpus. Mol Biol Evol 2019; 36:2778-2789. [PMID: 31504759 DOI: 10.1093/molbev/msz186] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2023] Open
Abstract
Most eukaryotes inherit their mitochondria from only one of their parents. When there are different sexes, it is almost always the maternal mitochondria that are transmitted. Indeed, maternal uniparental inheritance has been reported for the brown alga Ectocarpus but we show in this study that different strains of Ectocarpus can exhibit different patterns of inheritance: Ectocarpus siliculosus strains showed maternal uniparental inheritance, as expected, but crosses using different Ectocarpus species 7 strains exhibited either paternal uniparental inheritance or an unusual pattern of transmission where progeny inherited either maternal or paternal mitochondria, but not both. A possible correlation between the pattern of mitochondrial inheritance and male gamete parthenogenesis was investigated. Moreover, in contrast to observations in the green lineage, we did not detect any change in the pattern of mitochondrial inheritance in mutant strains affected in life cycle progression. Finally, an analysis of field-isolated strains provided evidence of mitochondrial genome recombination in both Ectocarpus species.
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Affiliation(s)
- Laure Mignerot
- Sorbonne Université, CNRS, Algal Genetics Group, UMR 8227 Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff (SBR), Roscoff, France
| | | | | | - Marie-Mathilde Perrineau
- Sorbonne Université, CNRS, Algal Genetics Group, UMR 8227 Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff (SBR), Roscoff, France
- The Scottish Association for Marine Science, Scottish Marine Institute, Oban, Argyll, Scotland
| | - Delphine Scornet
- Sorbonne Université, CNRS, Algal Genetics Group, UMR 8227 Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff (SBR), Roscoff, France
| | - Florian Pontheaux
- Sorbonne Université, CNRS, Algal Genetics Group, UMR 8227 Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff (SBR), Roscoff, France
| | - Walid Djema
- Inria Sophia-Antipolis, Côte d'Azur University, Bicore and McTAO Teams, France
| | - Yacine Badis
- Sorbonne Université, CNRS, Algal Genetics Group, UMR 8227 Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff (SBR), Roscoff, France
- The Scottish Association for Marine Science, Scottish Marine Institute, Oban, Argyll, Scotland
| | | | - Susana M Coelho
- Sorbonne Université, CNRS, Algal Genetics Group, UMR 8227 Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff (SBR), Roscoff, France
| | - J Mark Cock
- Sorbonne Université, CNRS, Algal Genetics Group, UMR 8227 Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff (SBR), Roscoff, France
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10
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Kariyawasam T, Joo S, Lee J, Toor D, Gao AF, Noh KC, Lee JH. TALE homeobox heterodimer GSM1/GSP1 is a molecular switch that prevents unwarranted genetic recombination in Chlamydomonas. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 100:938-953. [PMID: 31368133 DOI: 10.1111/tpj.14486] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 07/23/2019] [Accepted: 07/24/2019] [Indexed: 06/10/2023]
Abstract
Eukaryotic sexual life cycles alternate between haploid and diploid stages, the transitions between which are delineated by cell fusion and meiotic division. Transcription factors in the TALE-class homeobox family, GSM1 and GSP1, predominantly control gene expression for the haploid-to-diploid transition during sexual reproduction in the unicellular green alga, Chlamydomonas reinhardtii. To understand the roles that GSM1 and GSP1 play in zygote development, we used gsm1 and gsp1 mutants and examined fused gametes that normally undergo the multiple organellar fusions required for the genetic unity of the zygotes. In gsm1 and gsp1 zygotes, no fusion was observed for the nucleus and chloroplast. Surprisingly, mitochondria and endoplasmic reticulum, which undergo dynamic autologous fusion/fission, did not undergo heterologous fusions in gsm1 or gsp1 zygotes. Furthermore, the mutants failed to resorb their flagella, an event that normally renders the zygotes immotile. When gsm1 and gsp1 zygotes resumed the mitotic cycle, their two nuclei fused prior to mitosis, but neither chloroplastic nor mitochondrial fusion took place, suggesting that these fusions are specifically turned on by GSM1/GSP1. Taken together, this study shows that organellar restructuring during zygotic diploidization does not occur by default but is triggered by a combinatorial switch, the GSM1/GSP1 dyad. This switch may represent an ancient mechanism that evolved to restrict genetic recombination during sexual development.
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Affiliation(s)
| | - Sunjoo Joo
- Department of Botany, University of British Columbia, Vancouver, Canada
| | - Jenny Lee
- Department of Botany, University of British Columbia, Vancouver, Canada
| | - Deepak Toor
- Department of Botany, University of British Columbia, Vancouver, Canada
| | - Ally F Gao
- Department of Botany, University of British Columbia, Vancouver, Canada
| | - Kyung-Chul Noh
- Department of Biology, Washington University, St. Louis, MO, USA
| | - Jae-Hyeok Lee
- Department of Botany, University of British Columbia, Vancouver, Canada
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11
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Evolution, Initiation, and Diversity in Early Plant Embryogenesis. Dev Cell 2019; 50:533-543. [DOI: 10.1016/j.devcel.2019.07.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 06/07/2019] [Accepted: 07/07/2019] [Indexed: 11/22/2022]
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12
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Kajikawa M, Yamauchi M, Shinkawa H, Tanaka M, Hatano K, Nishimura Y, Kato M, Fukuzawa H. Isolation and Characterization of Chlamydomonas Autophagy-Related Mutants in Nutrient-Deficient Conditions. PLANT & CELL PHYSIOLOGY 2019; 60:126-138. [PMID: 30295899 DOI: 10.1093/pcp/pcy193] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 09/17/2018] [Indexed: 05/08/2023]
Abstract
Autophagy is a recycling system for amino acids and carbon- and nitrogen (N)-containing compounds. To date, the functional importance of autophagy in microalgae in nutrient-deficient conditions has not been evaluated by using autophagy-defective mutants. Here, we provide evidence which supports the following notions by characterizing an insertional mutant of the autophagy-related gene ATG8, encoding a ubiquitin-like protein necessary for the formation of the autophagosome in the green alga, Chlamydomonas reinhardtii. First, ATG8 is required for maintenance of cell survival and Chl content in N-, sulfur- and phosphate-deficient conditions. Secondly, ATG8 supports the degradation of triacylglycerol and lipid droplets after the resupply of N to cells cultured in N-limiting conditions. Thirdly, ATG8 is also necessary for accumulation of starch in phosphate-deficient conditions. Additionally, autophagy is not essential for maternal inheritance of the organelle genomes in gametogenesis.
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Affiliation(s)
| | - Marika Yamauchi
- Graduate School of Humanities and Sciences, Ochanomizu University, Tokyo, Japan
| | - Haruka Shinkawa
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Manabu Tanaka
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | - Kyoko Hatano
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | | | - Misako Kato
- Graduate School of Humanities and Sciences, Ochanomizu University, Tokyo, Japan
| | - Hideya Fukuzawa
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
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Joo S, Wang MH, Lui G, Lee J, Barnas A, Kim E, Sudek S, Worden AZ, Lee JH. Common ancestry of heterodimerizing TALE homeobox transcription factors across Metazoa and Archaeplastida. BMC Biol 2018; 16:136. [PMID: 30396330 PMCID: PMC6219170 DOI: 10.1186/s12915-018-0605-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 10/25/2018] [Indexed: 12/22/2022] Open
Abstract
Background Complex multicellularity requires elaborate developmental mechanisms, often based on the versatility of heterodimeric transcription factor (TF) interactions. Homeobox TFs in the TALE superclass are deeply embedded in the gene regulatory networks that orchestrate embryogenesis. Knotted-like homeobox (KNOX) TFs, homologous to animal MEIS, have been found to drive the haploid-to-diploid transition in both unicellular green algae and land plants via heterodimerization with other TALE superclass TFs, demonstrating remarkable functional conservation of a developmental TF across lineages that diverged one billion years ago. Here, we sought to delineate whether TALE-TALE heterodimerization is ancestral to eukaryotes. Results We analyzed TALE endowment in the algal radiations of Archaeplastida, ancestral to land plants. Homeodomain phylogeny and bioinformatics analysis partitioned TALEs into two broad groups, KNOX and non-KNOX. Each group shares previously defined heterodimerization domains, plant KNOX-homology in the KNOX group and animal PBC-homology in the non-KNOX group, indicating their deep ancestry. Protein-protein interaction experiments showed that the TALEs in the two groups all participated in heterodimerization. Conclusions Our study indicates that the TF dyads consisting of KNOX/MEIS and PBC-containing TALEs must have evolved early in eukaryotic evolution. Based on our results, we hypothesize that in early eukaryotes, the TALE heterodimeric configuration provided transcription-on switches via dimerization-dependent subcellular localization, ensuring execution of the haploid-to-diploid transition only when the gamete fusion is correctly executed between appropriate partner gametes. The TALE switch then diversified in the several lineages that engage in a complex multicellular organization. Electronic supplementary material The online version of this article (10.1186/s12915-018-0605-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sunjoo Joo
- Department of Botany, University of British Columbia, 6270 University Blvd, Vancouver, BC, V6T 1Z4, Canada
| | - Ming Hsiu Wang
- Department of Botany, University of British Columbia, 6270 University Blvd, Vancouver, BC, V6T 1Z4, Canada
| | - Gary Lui
- Department of Botany, University of British Columbia, 6270 University Blvd, Vancouver, BC, V6T 1Z4, Canada
| | - Jenny Lee
- Department of Botany, University of British Columbia, 6270 University Blvd, Vancouver, BC, V6T 1Z4, Canada
| | - Andrew Barnas
- Department of Botany, University of British Columbia, 6270 University Blvd, Vancouver, BC, V6T 1Z4, Canada
| | - Eunsoo Kim
- Division of Invertebrate Zoology and Sackler Institute for Comparative Genomics, American Museum of Natural History, 200 Central Park West, New York, NY, 10024, USA
| | - Sebastian Sudek
- Monterey Bay Aquarium Research Institute, 7700 Sandholdt Rd, Moss Landing, CA, 95039, USA
| | - Alexandra Z Worden
- Monterey Bay Aquarium Research Institute, 7700 Sandholdt Rd, Moss Landing, CA, 95039, USA
| | - Jae-Hyeok Lee
- Department of Botany, University of British Columbia, 6270 University Blvd, Vancouver, BC, V6T 1Z4, Canada.
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14
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Kobayashi Y, Misumi O, Odahara M, Ishibashi K, Hirono M, Hidaka K, Endo M, Sugiyama H, Iwasaki H, Kuroiwa T, Shikanai T, Nishimura Y. Holliday junction resolvases mediate chloroplast nucleoid segregation. Science 2018; 356:631-634. [PMID: 28495749 DOI: 10.1126/science.aan0038] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 04/14/2017] [Indexed: 01/11/2023]
Abstract
Holliday junctions, four-stranded DNA structures formed during homologous recombination, are disentangled by resolvases that have been found in prokaryotes and eukaryotes but not in plant organelles. Here, we identify monokaryotic chloroplast 1 (MOC1) as a Holliday junction resolvase in chloroplasts by analyzing a green alga Chlamydomonas reinhardtii mutant defective in chloroplast nucleoid (DNA-protein complex) segregation. MOC1 is structurally similar to a bacterial Holliday junction resolvase, resistance to ultraviolet (Ruv) C, and genetically conserved among green plants. Reduced or no expression of MOC1 in Arabidopsis thaliana leads to growth defects and aberrant chloroplast nucleoid segregation. In vitro biochemical analysis and high-speed atomic force microscopic analysis revealed that A. thaliana MOC 1 (AtMOC1) binds and cleaves the core of Holliday junctions symmetrically. MOC1 may mediate chloroplast nucleoid segregation in green plants by resolving Holliday junctions.
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Affiliation(s)
- Yusuke Kobayashi
- Laboratory of Plant Molecular Genetics, Department of Botany, Kyoto University, Oiwake-cho, Kita-Shirakawa, Kyoto 606-8502, Japan
| | - Osami Misumi
- Department of Biological Science and Chemistry, Faculty of Science, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi 753-8512, Japan
| | - Masaki Odahara
- Department of Life Science, College of Science, Rikkyo (St. Paul's) University, 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo 171-8501, Japan
| | - Kota Ishibashi
- Laboratory of Plant Molecular Genetics, Department of Botany, Kyoto University, Oiwake-cho, Kita-Shirakawa, Kyoto 606-8502, Japan
| | - Masafumi Hirono
- Department of Frontier Bioscience, Hosei University, Tokyo 184-8584, Japan
| | - Kumi Hidaka
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan
| | - Masayuki Endo
- Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Sakyo, Kyoto 606-8501, Japan
| | - Hiroshi Sugiyama
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan.,Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Sakyo, Kyoto 606-8501, Japan
| | - Hiroshi Iwasaki
- Department of Biological Sciences, School and Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Meguro-ku, Tokyo, Japan
| | - Tsuneyoshi Kuroiwa
- Department of Chemical and Biological Science, Faculty of Science, Japan Women's University, 2-8-1 Mejirodai, Bunkyo-ku, Tokyo 112-8681, Japan
| | - Toshiharu Shikanai
- Laboratory of Plant Molecular Genetics, Department of Botany, Kyoto University, Oiwake-cho, Kita-Shirakawa, Kyoto 606-8502, Japan
| | - Yoshiki Nishimura
- Laboratory of Plant Molecular Genetics, Department of Botany, Kyoto University, Oiwake-cho, Kita-Shirakawa, Kyoto 606-8502, Japan.
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15
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Joo S, Nishimura Y, Cronmiller E, Hong RH, Kariyawasam T, Wang MH, Shao NC, El Akkad SED, Suzuki T, Higashiyama T, Jin E, Lee JH. Gene Regulatory Networks for the Haploid-to-Diploid Transition of Chlamydomonas reinhardtii. PLANT PHYSIOLOGY 2017; 175:314-332. [PMID: 28710131 PMCID: PMC5580766 DOI: 10.1104/pp.17.00731] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 07/12/2017] [Indexed: 05/20/2023]
Abstract
The sexual cycle of the unicellular Chlamydomonas reinhardtii culminates in the formation of diploid zygotes that differentiate into dormant spores that eventually undergo meiosis. Mating between gametes induces rapid cell wall shedding via the enzyme g-lysin; cell fusion is followed by heterodimerization of sex-specific homeobox transcription factors, GSM1 and GSP1, and initiation of zygote-specific gene expression. To investigate the genetic underpinnings of the zygote developmental pathway, we performed comparative transcriptome analysis of both pre- and post-fertilization samples. We identified 253 transcripts specifically enriched in early zygotes, 82% of which were not up-regulated in gsp1 null zygotes. We also found that the GSM1/GSP1 heterodimer negatively regulates the vegetative wall program at the posttranscriptional level, enabling prompt transition from vegetative wall to zygotic wall assembly. Annotation of the g-lysin-induced and early zygote genes reveals distinct vegetative and zygotic wall programs, supported by concerted up-regulation of genes encoding cell wall-modifying enzymes and proteins involved in nucleotide-sugar metabolism. The haploid-to-diploid transition in Chlamydomonas is masterfully controlled by the GSM1/GSP1 heterodimer, translating fertilization and gamete coalescence into a bona fide differentiation program. The fertilization-triggered integration of genes required to make related, but structurally and functionally distinct organelles-the vegetative versus zygote cell wall-presents a likely scenario for the evolution of complex developmental gene regulatory networks.
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Affiliation(s)
- Sunjoo Joo
- Department of Botany, University of British Columbia, Vancouver, British Columbia V6T1Z4, Canada
| | - Yoshiki Nishimura
- Department of Botany, Graduate School of Science, Kyoto University, Oiwake-cho, Kita-Shirakawa, Sakyo-ku, Kyoto 606-8502, Japan
| | - Evan Cronmiller
- Department of Botany, University of British Columbia, Vancouver, British Columbia V6T1Z4, Canada
| | - Ran Ha Hong
- Department of Botany, University of British Columbia, Vancouver, British Columbia V6T1Z4, Canada
| | - Thamali Kariyawasam
- Department of Botany, University of British Columbia, Vancouver, British Columbia V6T1Z4, Canada
| | - Ming Hsiu Wang
- Department of Botany, University of British Columbia, Vancouver, British Columbia V6T1Z4, Canada
| | - Nai Chun Shao
- Department of Botany, University of British Columbia, Vancouver, British Columbia V6T1Z4, Canada
| | - Saif-El-Din El Akkad
- Department of Botany, University of British Columbia, Vancouver, British Columbia V6T1Z4, Canada
| | - Takamasa Suzuki
- ERATO, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Tetsuya Higashiyama
- ERATO, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Eonseon Jin
- Department Life Sciences, Research Institute for Natural Sciences, Hanyang University, 222 Wangsipri-ro, Sungdong-gu, Seoul 133-791, Republic of Korea
| | - Jae-Hyeok Lee
- Department of Botany, University of British Columbia, Vancouver, British Columbia V6T1Z4, Canada
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16
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Abstract
The life cycles of eukaryotes alternate between haploid and diploid phases, which are initiated by meiosis and gamete fusion, respectively. In both ascomycete and basidiomycete fungi and chlorophyte algae, the haploid-to-diploid transition is regulated by a pair of paralogous homeodomain protein encoding genes. That a common genetic program controls the haploid-to-diploid transition in phylogenetically disparate eukaryotic lineages suggests this may be the ancestral function for homeodomain proteins. Multicellularity has evolved independently in many eukaryotic lineages in either one or both phases of the life cycle. Organisms, such as land plants, exhibiting a life cycle whereby multicellular bodies develop in both the haploid and diploid phases are often referred to as possessing an alternation of generations. We review recent progress on understanding the genetic basis for the land plant alternation of generations and highlight the roles that homeodomain-encoding genes may have played in the evolution of complex multicellularity in this lineage.
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Affiliation(s)
- John L Bowman
- School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia;
- Department of Plant Biology, University of California, Davis, California 95616
| | - Keiko Sakakibara
- School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia;
- Department of Life Science, College of Science, Rikkyo University, Tokyo 171-8501, Japan
| | - Chihiro Furumizu
- School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia;
| | - Tom Dierschke
- School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia;
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17
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Identification and Characterization of a cis-Regulatory Element for Zygotic Gene Expression in Chlamydomonas reinhardtii. G3-GENES GENOMES GENETICS 2016; 6:1541-8. [PMID: 27172209 PMCID: PMC4889651 DOI: 10.1534/g3.116.029181] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Upon fertilization Chlamydomonas reinhardtii zygotes undergo a program of differentiation into a diploid zygospore that is accompanied by transcription of hundreds of zygote-specific genes. We identified a distinct sequence motif we term a zygotic response element (ZYRE) that is highly enriched in promoter regions of C reinhardtii early zygotic genes. A luciferase reporter assay was used to show that native ZYRE motifs within the promoter of zygotic gene ZYS3 or intron of zygotic gene DMT4 are necessary for zygotic induction. A synthetic luciferase reporter with a minimal promoter was used to show that ZYRE motifs introduced upstream are sufficient to confer zygotic upregulation, and that ZYRE-controlled zygotic transcription is dependent on the homeodomain transcription factor GSP1. We predict that ZYRE motifs will correspond to binding sites for the homeodomain proteins GSP1-GSM1 that heterodimerize and activate zygotic gene expression in early zygotes.
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18
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19
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Aoyama H, Saitoh S, Kuroiwa T, Nakamura S. Comparative analysis of zygospore transcripts during early germination in Chlamydomonas reinhardtii. JOURNAL OF PLANT PHYSIOLOGY 2014; 171:1685-1692. [PMID: 25209695 DOI: 10.1016/j.jplph.2014.07.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2014] [Revised: 07/31/2014] [Accepted: 07/31/2014] [Indexed: 06/03/2023]
Abstract
The unicellular green alga Chlamydomonas reinhardtii has a haplontic life cycle, and forms diploid zygotes for reproduction. The zygospore, a sporulating zygote, begins germination in response to light signals, generating haploid progenies and inducing several cell-biological events; e.g., DNA synthesis and meiotic division, successively. Their regulatory mechanisms remain largely unknown, so we focused on the early stages of germination and analyzed the dynamics of gene expression associated with the germination process. The gene expression levels of zygospores at 1 and 6h after light exposure were analyzed by a next-generation sequencing platform, the 454 GS Junior. At 6h, the photosynthesis pathway, including its antenna proteins and two methionine metabolism-related genes (methionine synthase and sulfite reductase), were up-regulated compared to 1h after light exposure. Meanwhile, three uncharacterized genes that contained an antibiotic biosynthesis monooxygenase domain and an HSP20/alpha crystallin family protein were specifically expressed at 1h after light exposure. These gene expressions were also verified by quantitative real-time PCR analysis. These results suggest that the photosynthesis and methionine synthesis pathways, both of which occur in the chloroplast, are activated in zygospores at around 6h after light exposure, and that some polyketides and/or a small heat shock protein may be related to the initiation of zygospore germination.
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Affiliation(s)
- Hiroaki Aoyama
- Center of Molecular Biosciences, Tropical Biosphere Research Center, University of the Ryukyus, Nishihara, Okinawa 903-0213; Laboratory of Cell and Functional Biology, Faculty of Science, University of the Ryukyus, Nishihara, Okinawa 903-0213.
| | - Seikoh Saitoh
- Center of Molecular Biosciences, Tropical Biosphere Research Center, University of the Ryukyus, Nishihara, Okinawa 903-0213
| | - Tsuneyoshi Kuroiwa
- Initiative Research Unit, College of Science, Rikkyo University, Nishi-Ikebukuro, Tokyo, 171-8501
| | - Soichi Nakamura
- Laboratory of Cell and Functional Biology, Faculty of Science, University of the Ryukyus, Nishihara, Okinawa 903-0213
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20
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Abstract
The green lineage of chlorophyte algae and streptophytes form a large and diverse clade with multiple independent transitions to produce multicellular and/or macroscopically complex organization. In this review, I focus on two of the best-studied multicellular groups of green algae: charophytes and volvocines. Charophyte algae are the closest relatives of land plants and encompass the transition from unicellularity to simple multicellularity. Many of the innovations present in land plants have their roots in the cell and developmental biology of charophyte algae. Volvocine algae evolved an independent route to multicellularity that is captured by a graded series of increasing cell-type specialization and developmental complexity. The study of volvocine algae has provided unprecedented insights into the innovations required to achieve multicellularity.
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Affiliation(s)
- James G Umen
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132
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21
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Wang L, Yamano T, Kajikawa M, Hirono M, Fukuzawa H. Isolation and characterization of novel high-CO2-requiring mutants of Chlamydomonas reinhardtii. PHOTOSYNTHESIS RESEARCH 2014; 121:175-84. [PMID: 24549931 DOI: 10.1007/s11120-014-9983-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2013] [Accepted: 02/05/2014] [Indexed: 05/11/2023]
Abstract
Aquatic microalgae induce a carbon-concentrating mechanism (CCM) to maintain photosynthetic activity in low-CO2 (LC) conditions. Although the molecular mechanism of the CCM has been investigated using the single-cell green alga Chlamydomonas reinhardtii, and several CCM-related genes have been identified by analyzing high-CO2 (HC)-requiring mutants, many aspects of the CO2-signal transduction pathways remain to be elucidated. In this study, we report the isolation of novel HC-requiring mutants defective in the induction of CCM by DNA tagging. Growth rates of 20,000 transformants grown under HC and LC conditions were compared, and three HC-requiring mutants (H24, H82, and P103) were isolated. The photosynthetic CO2-exchange activities of these mutants were significantly decreased compared with that of wild-type cells, and accumulation of HLA3 and both LCIA and HLA3 were absent in mutants H24 and H82, respectively. Although the insertion of the marker gene and the HC-requiring phenotype were linked in the tetrad progeny of H82, and a calcium-sensing receptor CAS was disrupted by the insertion, exogenous expression of CAS alone could not complement the HC-requiring phenotype.
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Affiliation(s)
- Lianyong Wang
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan
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22
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Zhan GM, Li RJ, Hu ZY, Liu J, Deng LB, Lu SY, Hua W. Cosuppression of RBCS3B in Arabidopsis leads to severe photoinhibition caused by ROS accumulation. PLANT CELL REPORTS 2014; 33:1091-108. [PMID: 24682522 DOI: 10.1007/s00299-014-1597-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 02/13/2014] [Accepted: 03/02/2014] [Indexed: 05/08/2023]
Abstract
Cosuppression of an Arabidopsis Rubisco small subunit gene RBCS3B at Arabidopsis resulted in albino or pale green phenotypes which were caused by ROS accumulation As the most abundant protein on Earth, Rubisco has received much attention in the past decades. Even so, its function is still not understood thoroughly. In this paper, four Arabidopsis transgenic lines (RBCS3B-7, 18, 33, and 35) with albino or pale green phenotypes were obtained by transformation with a construct driving expression of sense RBCS3B, a Rubisco small subunit gene. The phenotypes produced in these transgenic lines were found to be caused by cosuppression. Among these lines, RBCS3B-7 displayed the most severe phenotypes including reduced height, developmental arrest and plant mortality before flowering when grown under normal light on soil. Chloroplast numbers in mesophyll cells were decreased compared to WT, and stacked thylakoids of chloroplasts were broken down gradually in RBCS3B-7 throughout development. In addition, the RBCS3B-7 line was light sensitive, and PSII activity measurement revealed that RBCS3B-7 suffered severe photoinhibition, even under normal light. We found that photoinhibition was due to accumulation of ROS, which accelerated photodamage of PSII and inhibited the repair of PSII in RBCS3B-7.
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Affiliation(s)
- Gao-Miao Zhan
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, China
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23
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Abstract
Sexual reproduction is a nearly universal feature of eukaryotic organisms. Given its ubiquity and shared core features, sex is thought to have arisen once in the last common ancestor to all eukaryotes. Using the perspectives of molecular genetics and cell biology, we consider documented and hypothetical scenarios for the instantiation and evolution of meiosis, fertilization, sex determination, uniparental inheritance of organelle genomes, and speciation.
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Affiliation(s)
- Ursula Goodenough
- Department of Biology, Washington University, St. Louis, Missouri 63130
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24
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Nourbakhsh A, Collakova E, Gillaspy GE. Characterization of the inositol monophosphatase gene family in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2014; 5:725. [PMID: 25620968 PMCID: PMC4288329 DOI: 10.3389/fpls.2014.00725] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 12/01/2014] [Indexed: 05/08/2023]
Abstract
Synthesis of myo-inositol is crucial in multicellular eukaryotes for production of phosphatidylinositol and inositol phosphate signaling molecules. The myo-inositol monophosphatase (IMP) enzyme is required for the synthesis of myo-inositol, breakdown of inositol (1,4,5)-trisphosphate, a second messenger involved in Ca(2+) signaling, and synthesis of L-galactose, a precursor of ascorbic acid. Two myo-inositol monophosphatase -like (IMPL) genes in Arabidopsis encode chloroplast proteins with homology to the prokaryotic IMPs and one of these, IMPL2, can complement a bacterial histidinol 1-phosphate phosphatase mutant defective in histidine synthesis, indicating an important role for IMPL2 in amino acid synthesis. To delineate how this small gene family functions in inositol synthesis and metabolism, we sought to compare recombinant enzyme activities, expression patterns, and impact of genetic loss-of-function mutations for each. Our data show that purified IMPL2 protein is an active histidinol-phosphate phosphatase enzyme in contrast to the IMPL1 enzyme, which has the ability to hydrolyze D-galactose 1-phosphate, and D-myo-inositol 1-phosphate, a breakdown product of D-inositol (1,4,5) trisphosphate. Expression studies indicated that all three genes are expressed in multiple tissues, however, IMPL1 expression is restricted to above-ground tissues only. Identification and characterization of impl1 and impl2 mutants revealed no viable mutants for IMPL1, while two different impl2 mutants were identified and shown to be severely compromised in growth, which can be rescued by histidine. Analyses of metabolite levels in impl2 and complemented mutants reveals impl2 mutant growth is impacted by alterations in the histidine biosynthesis pathway, but does not impact myo-inositol synthesis. Together, these data indicate that IMPL2 functions in the histidine biosynthetic pathway, while IMP and IMPL1 catalyze the hydrolysis of inositol- and galactose-phosphates in the plant cell.
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Affiliation(s)
- Aida Nourbakhsh
- Department of Human and Molecular Genetics, Virginia Commonwealth UniversityRichmond, VA, USA
| | - Eva Collakova
- Department of Plant Pathology, Physiology, and Weed Science, Virginia Polytechnic Institute and State UniversityBlacksburg, VA, USA
| | - Glenda E. Gillaspy
- Department of Biochemistry, Virginia Polytechnic Institute and State UniversityBlacksburg, VA, USA
- *Correspondence: Glenda E. Gillaspy, Department of Biochemistry, Virginia Polytechnic Institute and State University, 542 Latham Hall, Blacksburg, VA 24061, USA e-mail:
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25
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Sex determination directs uniparental mitochondrial inheritance in Phycomyces. EUKARYOTIC CELL 2013; 13:186-9. [PMID: 24243797 DOI: 10.1128/ec.00203-13] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Uniparental inheritance (UPI) of mitochondria is common among eukaryotes. The underlying molecular basis by which the sexes of the parents control this non-Mendelian pattern of inheritance is yet to be fully understood. Two major factors have complicated the understanding of the role of sex-specific genes in the UPI phenomenon: in many cases (i) fusion occurs between cells of unequal size or (ii) mating requires a large region of the genome or chromosome that includes genes unrelated to sex determination. The fungus Phycomyces blakesleeanus is a member of the Mucoromycotina and has a simple mating type locus encoding only one high-mobility group (HMG) domain protein, and mating occurs by fusion of isogamous cells, thus providing a model system without the limitations mentioned above. Analysis of more than 250 progeny from a series of genetic crosses between wild-type strains of Phycomyces revealed a correlation between the individual genes in the mating type locus and UPI of mitochondria. Inheritance is from the plus (+) sex type and is associated with degradation of the mtDNA from the minus (-) parent. These findings suggest that UPI can be directly controlled by genes that determine sex identity, independent of cell size or the complexity of the genetic composition of a sex chromosome.
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26
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Ning J, Otto TD, Pfander C, Schwach F, Brochet M, Bushell E, Goulding D, Sanders M, Lefebvre PA, Pei J, Grishin NV, Vanderlaan G, Billker O, Snell WJ. Comparative genomics in Chlamydomonas and Plasmodium identifies an ancient nuclear envelope protein family essential for sexual reproduction in protists, fungi, plants, and vertebrates. Genes Dev 2013; 27:1198-215. [DOI: 10.1101/gad.212746.112] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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27
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Sato M, Sato K. Maternal inheritance of mitochondrial DNA by diverse mechanisms to eliminate paternal mitochondrial DNA. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:1979-84. [PMID: 23524114 DOI: 10.1016/j.bbamcr.2013.03.010] [Citation(s) in RCA: 157] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Revised: 03/06/2013] [Accepted: 03/10/2013] [Indexed: 10/27/2022]
Abstract
The mitochondrion is an organelle that has its own DNA (mtDNA). Mitochondria play essential roles in energy production and in various cellular processes such as metabolism and signal transduction. In most animals, including humans, although the sperm-derived paternal mitochondria enter the oocyte cytoplasm after fertilization, their mtDNA is never transmitted to the offspring. This pattern of mtDNA inheritance is well known as "maternal inheritance." However, how the paternal mitochondria and mtDNA are eliminated from the cytoplasm of gametes or zygotes remains an enigma. Recently, a variety of mechanisms, including specific nuclease-dependent systems, ubiquitin-proteasome system, and autophagy have been shown to degrade the paternal mtDNA or the paternal mitochondria themselves in order to prevent paternal mtDNA transmission. In this review, we will address the current state of knowledge of the molecular mechanisms underlying the elimination of paternal mtDNA or mitochondrial structures for ensuring the maternal transmission of mtDNA.
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Affiliation(s)
- Miyuki Sato
- Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Gunma, Japan
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28
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Sakakibara K, Ando S, Yip HK, Tamada Y, Hiwatashi Y, Murata T, Deguchi H, Hasebe M, Bowman JL. KNOX2 genes regulate the haploid-to-diploid morphological transition in land plants. Science 2013; 339:1067-70. [PMID: 23449590 DOI: 10.1126/science.1230082] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Unlike animals, land plants undergo an alternation of generations, producing multicellular bodies in both haploid (1n: gametophyte) and diploid (2n: sporophyte) generations. Plant body plans in each generation are regulated by distinct developmental programs initiated at either meiosis or fertilization, respectively. In mosses, the haploid gametophyte generation is dominant, whereas in vascular plants-including ferns, gymnosperms, and angiosperms-the diploid sporophyte generation is dominant. Deletion of the class 2 KNOTTED1-LIKE HOMEOBOX (KNOX2) transcription factors in the moss Physcomitrella patens results in the development of gametophyte bodies from diploid embryos without meiosis. Thus, KNOX2 acts to prevent the haploid-specific body plan from developing in the diploid plant body, indicating a critical role for the evolution of KNOX2 in establishing an alternation of generations in land plants.
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Affiliation(s)
- Keiko Sakakibara
- Department of Biological Science, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Japan.
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