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Herbert L, Vernet A, Frouin J, Meunier AC, Di Mattia J, Wang M, Sidhu GK, Mathis L, Nicolas A, Guiderdoni E, Fayos I. dCas9-SPO11-1 locally stimulates meiotic recombination in rice. FRONTIERS IN PLANT SCIENCE 2025; 16:1580225. [PMID: 40376157 PMCID: PMC12078263 DOI: 10.3389/fpls.2025.1580225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2025] [Accepted: 03/31/2025] [Indexed: 05/18/2025]
Abstract
Introduction Meiotic crossovers shuffle the genetic information transmitted by the gametes. However, the potential to recover all the combinations of the parental alleles remains limited in most organisms, including plants, by the occurrence of only few crossovers per chromosome and a prominent bias in their spatial distribution. Thus, novel methods for stimulating recombination frequencies and/or modifying their location are highly desired to accelerate plant breeding. Methods Here, we investigate the use of a dCas9-SPO11-1 fusion and clusters of 11 gRNAs to alter meiotic recombination in two chromosomal regions of a rice hybrid (KalingaIII/Kitaake). To accurately genotype rare recombinants in regions of few kbp, we improved the digital PCR-based pollen-typing method in parallel. Results Expression of the dCas9-SPO11-1 fusion protein under the ubiquitous ZmUbi1 promoter was obtained in leaves/anthers/meiocytes and found to complement the sterility of the Osspo11-1 mutant line. We observed a 3.27-fold increase over wild-type (p<0.001) of recombinant pollens in a transgenic hybrid line (7a) targeting a chromosome 7 region. In the offspring plant 7a1, a significant 2.05-fold increase (p=0.048) was observed in the central interval (7.2 kb) of the Chr. 7 target region. This stimulation of meiotic recombination is consistent with the expression of the dCas9-SPO11-1 fusion and gRNAs as well as with the ChIP-revealed binding of dCas9-SPO11-1 to the targeted region. In contrast, no stimulation was observed in other transgenic lines deficient in the above pre-requisite features, expressing the dCas9-SPO11-1 fusion but no gRNAs or targeting a Chr.9 region. Discussion These results open new avenues to locally stimulate meiotic recombination in crop genomes and paves the way for a future implementation in plant breeding programs.
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Affiliation(s)
| | - Aurore Vernet
- Centre de coopération internationale en recherche agronomique pour le développement (CIRAD), Unité mixte de recherche - Amélioration génétique et adaptation des plantes méditerranéennes et tropicales (UMR AGAP) Institut, Montpellier, France
- Unité mixte de recherche - Amélioration génétique et adaptation des plantes méditerranéennes et tropicales (UMR AGAP) Institut, Université de Montpellier, Centre de coopération internationale en recherche agronomique pour le développement (CIRAD), Institut national de recherche pour l'agriculture, l'alimentation et l'environnement (INRAE), Institut Agro, Montpellier, France
| | - Julien Frouin
- Centre de coopération internationale en recherche agronomique pour le développement (CIRAD), Unité mixte de recherche - Amélioration génétique et adaptation des plantes méditerranéennes et tropicales (UMR AGAP) Institut, Montpellier, France
- Unité mixte de recherche - Amélioration génétique et adaptation des plantes méditerranéennes et tropicales (UMR AGAP) Institut, Université de Montpellier, Centre de coopération internationale en recherche agronomique pour le développement (CIRAD), Institut national de recherche pour l'agriculture, l'alimentation et l'environnement (INRAE), Institut Agro, Montpellier, France
| | - Anne Cécile Meunier
- Centre de coopération internationale en recherche agronomique pour le développement (CIRAD), Unité mixte de recherche - Amélioration génétique et adaptation des plantes méditerranéennes et tropicales (UMR AGAP) Institut, Montpellier, France
- Unité mixte de recherche - Amélioration génétique et adaptation des plantes méditerranéennes et tropicales (UMR AGAP) Institut, Université de Montpellier, Centre de coopération internationale en recherche agronomique pour le développement (CIRAD), Institut national de recherche pour l'agriculture, l'alimentation et l'environnement (INRAE), Institut Agro, Montpellier, France
| | - Jeremy Di Mattia
- Ingénierie et Analyse en Génétique Environnementale (IAGE), Montpellier, France
| | - Minghui Wang
- Meiogenix Inc., Center for Life Science Ventures Cornell University, Ithaca, NY, United States
| | - Gaganpreet K. Sidhu
- Meiogenix Inc., Center for Life Science Ventures Cornell University, Ithaca, NY, United States
| | | | - Alain Nicolas
- Meiogenix SA, Paris, France
- IRCAN (Institute for Research on Cancer and Aging), CNRS (Centre national de la recherche scientifique) UMR7284, INSERM (Institut national de la santé et de la recherche médicale) U1081, Université Côte d’Azur, Nice, France
| | - Emmanuel Guiderdoni
- Centre de coopération internationale en recherche agronomique pour le développement (CIRAD), Unité mixte de recherche - Amélioration génétique et adaptation des plantes méditerranéennes et tropicales (UMR AGAP) Institut, Montpellier, France
- Unité mixte de recherche - Amélioration génétique et adaptation des plantes méditerranéennes et tropicales (UMR AGAP) Institut, Université de Montpellier, Centre de coopération internationale en recherche agronomique pour le développement (CIRAD), Institut national de recherche pour l'agriculture, l'alimentation et l'environnement (INRAE), Institut Agro, Montpellier, France
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Cornaro L, Banfi C, Cavalleri A, van Dijk PJ, Radoeva T, Cucinotta M, Colombo L. Apomixis at high resolution: unravelling diplospory in Asteraceae. JOURNAL OF EXPERIMENTAL BOTANY 2025; 76:1644-1657. [PMID: 39673465 PMCID: PMC11981899 DOI: 10.1093/jxb/erae477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2024] [Accepted: 12/02/2024] [Indexed: 12/16/2024]
Abstract
Apomictic plants are able to produce clonal seeds. This reproductive system allows the one-step fixation of any valuable trait for subsequent generations and would pave the way for a revolution in the agricultural system. Despite this, the introduction of apomixis in sexually reproducing crops has been hampered due to the difficulty in characterizing its genetic regulation. In this study, we described the high-resolution characterization of apomeiosis in the apomictic model species Erigeron annuus, Chondrilla juncea, and Taraxacum officinale. We showed that apomeiosis differs from meiosis in a few critical steps, including homologous chromosome synapsis and segregation during meiosis I. We then compared megasporogenesis in three T. officinale genetic backgrounds, showing that diplospory is superimposed on the sexual pathway without severely altering the expression of crucial meiotic genes. Our findings will contribute to the identification of pivotal players controlling this intriguing asexual reproductive strategy.
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Affiliation(s)
- Letizia Cornaro
- Department of Biosciences, Università degli Studi di Milano, Via Giovanni Celoria 26, 20133 Milano, Italy
| | - Camilla Banfi
- Department of Biosciences, Università degli Studi di Milano, Via Giovanni Celoria 26, 20133 Milano, Italy
| | - Alex Cavalleri
- Department of Biosciences, Università degli Studi di Milano, Via Giovanni Celoria 26, 20133 Milano, Italy
| | - Peter J van Dijk
- Keygene N.V., Agro Business Park 90, 6708 PW Wageningen, The Netherlands
| | - Tatyana Radoeva
- Keygene N.V., Agro Business Park 90, 6708 PW Wageningen, The Netherlands
| | - Mara Cucinotta
- Department of Biosciences, Università degli Studi di Milano, Via Giovanni Celoria 26, 20133 Milano, Italy
| | - Lucia Colombo
- Department of Biosciences, Università degli Studi di Milano, Via Giovanni Celoria 26, 20133 Milano, Italy
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Rafiei N, Ronceret A. The plant early recombinosome: a high security complex to break DNA during meiosis. PLANT REPRODUCTION 2024; 37:421-440. [PMID: 39331138 PMCID: PMC11511760 DOI: 10.1007/s00497-024-00509-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2024] [Accepted: 08/26/2024] [Indexed: 09/28/2024]
Abstract
KEY MESSAGE The formacion of numerous unpredictable DNA Double Strand Breaks (DSBs) on chromosomes iniciates meiotic recombination. In this perspective, we propose a 'multi-key lock' model to secure the risky but necesary breaks as well as a 'one per pair of cromatids' model for the topoisomerase-like early recombinosome. During meiosis, homologous chromosomes recombine at few sites of crossing-overs (COs) to ensure correct segregation. The initiation of meiotic recombination involves the formation of DNA double strand breaks (DSBs) during prophase I. Too many DSBs are dangerous for genome integrity: if these DSBs are not properly repaired, it could potentially lead to chromosomal fragmentation. Too few DSBs are also problematic: if the obligate CO cannot form between bivalents, catastrophic unequal segregation of univalents lead to the formation of sterile aneuploid spores. Research on the regulation of the formation of these necessary but risky DSBs has recently advanced in yeast, mammals and plants. DNA DSBs are created by the enzymatic activity of the early recombinosome, a topoisomerase-like complex containing SPO11. This opinion paper reviews recent insights on the regulation of the SPO11 cofactors necessary for the introduction of temporally and spatially controlled DSBs. We propose that a 'multi-key-lock' model for each subunit of the early recombinosome complex is required to secure the formation of DSBs. We also discuss the hypothetical implications that the established topoisomerase-like nature of the SPO11 core-complex can have in creating DSB in only one of the two replicated chromatids of early prophase I meiotic chromosomes. This hypothetical 'one per pair of chromatids' DSB formation model could optimize the faithful repair of the self-inflicted DSBs. Each DSB could use three potential intact homologous DNA sequences as repair template: one from the sister chromatid and the two others from the homologous chromosomes.
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Affiliation(s)
- Nahid Rafiei
- Department of Plant Molecular Biology, Instituto de Biotecnología (IBT), Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México
| | - Arnaud Ronceret
- Department of Plant Molecular Biology, Instituto de Biotecnología (IBT), Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México.
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Wu T, Yang S, Fang J, Ye Y, Zhang Y, Gao J, Leng J, Zhang Z, Tang K, Bhat JA, Feng X. MutL homolog 1 participates in interference-sensitive meiotic crossover formation in soybean. PLANT PHYSIOLOGY 2024; 195:2579-2595. [PMID: 38492234 PMCID: PMC11288737 DOI: 10.1093/plphys/kiae165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 02/07/2024] [Accepted: 02/15/2024] [Indexed: 03/18/2024]
Abstract
MutL homolog 1 (MLH1), a member of the MutL homolog family, is required for normal recombination in most organisms. However, its role in soybean (Glycine max) remains unclear to date. Here, we characterized the Glycine max female and male sterility 1 (Gmfms1) mutation that reduces pollen grain viability and increases embryo sac abortion in soybean. Map-based cloning revealed that the causal gene of Gmfms1 is Glycine max MutL homolog 1 (GmMLH1), and CRISPR/Cas9 knockout approach further validated that disruption of GmMLH1 confers the female-male sterility phenotype in soybean. Loss of GmMLH1 function disrupted bivalent formation, leading to univalent mis-segregation during meiosis and ultimately to female-male sterility. The Gmmlh1 mutant showed about a 78.16% decrease in meiotic crossover frequency compared to the wild type. The residual chiasmata followed a Poisson distribution, suggesting that interference-sensitive crossover formation was affected in the Gmmlh1 mutant. Furthermore, GmMLH1 could interact with GmMLH3A and GmMLH3B both in vivo and in vitro. Overall, our work demonstrates that GmMLH1 participates in interference-sensitive crossover formation in soybean, and provides additional information about the conserved functions of MLH1 across plant species.
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Affiliation(s)
- Tao Wu
- Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Suxin Yang
- Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Junling Fang
- Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China
- College of Life Science, Jilin Agricultural University, Changchun 130118, China
| | - Yongheng Ye
- Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yaohua Zhang
- Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China
| | - Jinshan Gao
- Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China
| | - Jiantian Leng
- Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China
| | - Zhirui Zhang
- Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kuanqiang Tang
- Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China
| | | | - Xianzhong Feng
- Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China
- Zhejiang Lab, Hangzhou 311121, China
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Ronceret A, Bolaños‐Villegas P. Plant reproduction research in Latin America: Toward sustainable agriculture in a changing environment. PLANT-ENVIRONMENT INTERACTIONS (HOBOKEN, N.J.) 2024; 5:e10143. [PMID: 38764600 PMCID: PMC11101159 DOI: 10.1002/pei3.10143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 04/03/2024] [Accepted: 04/11/2024] [Indexed: 05/21/2024]
Abstract
Food production and food security depend on the ability of crops to cope with anthropogenic climate change and successfully produce seed. To guarantee food production well into the future, contemporary plant scientists in Latin America must carry out research on how plants respond to environmental stressors such as temperature, drought, and salinity. This review shows the opportunities to apply these results locally and abroad and points to the gaps that still exist in terms of reproductive processes with the purpose to better link research with translational work in plant breeding and biotechnology. Suggestions are put forth to address these gaps creatively in the face of chronic low investment in science with a focus on applicability.
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Affiliation(s)
- Arnaud Ronceret
- Instituto de Biotecnología/Universidad Nacional Autónoma de México (UNAM)CuernavacaMorelosMexico
| | - Pablo Bolaños‐Villegas
- Fabio Baudrit Agricultural Research StationUniversity of Costa RicaAlajuelaCosta Rica
- Lankester Botanical GardenUniversity of Costa RicaCartagoCosta Rica
- Faculty of Food and Agricultural Sciences, Rodrigo Facio Campus, School of AgronomyUniversity of Costa RicaSan JoseCosta Rica
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Jiang L, Guo T, Song X, Jiang H, Lu M, Luo J, Rossi V, He Y. MSH7 confers quantitative variation in pollen fertility and boosts grain yield in maize. PLANT BIOTECHNOLOGY JOURNAL 2024; 22:1372-1386. [PMID: 38263872 PMCID: PMC11022798 DOI: 10.1111/pbi.14272] [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: 08/16/2023] [Revised: 11/15/2023] [Accepted: 12/08/2023] [Indexed: 01/25/2024]
Abstract
Fertile pollen is critical for the survival, fitness, and dispersal of flowering plants, and directly contributes to crop productivity. Extensive mutational screening studies have been carried out to dissect the genetic regulatory network determining pollen fertility, but we still lack fundamental knowledge about whether and how pollen fertility is controlled in natural populations. We used a genome-wide association study (GWAS) to show that ZmGEN1A and ZmMSH7, two DNA repair-related genes, confer natural variation in maize pollen fertility. Mutants defective in these genes exhibited abnormalities in meiotic or post-meiotic DNA repair, leading to reduced pollen fertility. More importantly, ZmMSH7 showed evidence of selection during maize domestication, and its disruption resulted in a substantial increase in grain yield for both inbred and hybrid. Overall, our study describes the first systematic examination of natural genetic effects on pollen fertility in plants, providing valuable genetic resources for optimizing male fertility. In addition, we find that ZmMSH7 represents a candidate for improvement of grain yield.
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Affiliation(s)
- Luguang Jiang
- National Maize Improvement Center of China, College of Agronomy and BiotechnologyChina Agricultural UniversityBeijingChina
| | - Ting Guo
- Institute of Genetics and Developmental Biology, Key Laboratory of Seed InnovationChinese Academy of SciencesBeijingChina
| | - Xinyuan Song
- Jilin Provincial Key Laboratory of Agricultural Biotechnology, Agro‐Biotechnology Research InstituteJilin Academy of Agricultural SciencesChangchunChina
| | - Huan Jiang
- National Maize Improvement Center of China, College of Agronomy and BiotechnologyChina Agricultural UniversityBeijingChina
| | - Minhui Lu
- Center for Crop Functional Genomics and Molecular BreedingChina Agricultural UniversityBeijingChina
| | - Jinhong Luo
- National Maize Improvement Center of China, College of Agronomy and BiotechnologyChina Agricultural UniversityBeijingChina
- Institute of Genetics and Developmental Biology, Key Laboratory of Seed InnovationChinese Academy of SciencesBeijingChina
| | - Vincenzo Rossi
- Council for Agricultural Research and EconomicsResearch Centre for Cereal and Industrial CropsBergamoItaly
| | - Yan He
- National Maize Improvement Center of China, College of Agronomy and BiotechnologyChina Agricultural UniversityBeijingChina
- Institute of Genetics and Developmental Biology, Key Laboratory of Seed InnovationChinese Academy of SciencesBeijingChina
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Ren Z, Liu Y, Li L, Wang X, Zhou Y, Zhang M, Li Z, Yi F, Duan L. Deciphering transcriptional mechanisms of maize internodal elongation by regulatory network analysis. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:4503-4519. [PMID: 37170764 DOI: 10.1093/jxb/erad178] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 05/10/2023] [Indexed: 05/13/2023]
Abstract
The lengths of the basal internodes is an important factor for lodging resistance of maize (Zea mays). In this study, foliar application of coronatine (COR) to 10 cultivars at the V8 growth stage had different suppression effects on the length of the eighth internode, with three being categorized as strong-inhibition cultivars (SC), five as moderate (MC), and two as weak (WC). RNA-sequencing of the eighth internode of the cultivars revealed a total of 7895 internode elongation-regulating genes, including 777 transcription factors (TFs). Genes related to the hormones cytokinin, gibberellin, auxin, and ethylene in the SC group were significantly down-regulated compared to WC, and more cell-cycle regulatory factors and cell wall-related genes showed significant changes, which severely inhibited internode elongation. In addition, we used EMSAs to explore the direct regulatory relationship between two important TFs, ZmABI7 and ZmMYB117, which regulate the cell cycle and cell wall modification by directly binding to the promoters of their target genes ZmCYC1, ZmCYC3, ZmCYC7, and ZmCPP1. The transcriptome reported in this study will provide a useful resource for studying maize internode development, with potential use for targeted genetic control of internode length to improve the lodging resistance of maize.
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Affiliation(s)
- Zhaobin Ren
- State Key Laboratory of Plant Physiology and Biochemistry, Engineering Research Center of Plant Growth Regulator, Ministry of Education & College of Agronomy and Biotechnology, China Agricultural University, No.2 Yuanmingyuan West Road, Haidian, Beijing 100193, China
| | - Yingru Liu
- State Key Laboratory of Plant Physiology and Biochemistry, Engineering Research Center of Plant Growth Regulator, Ministry of Education & College of Agronomy and Biotechnology, China Agricultural University, No.2 Yuanmingyuan West Road, Haidian, Beijing 100193, China
- North China Key Laboratory for Crop Germplasm Resources, Ministry of Education, State Key Laboratory of North China Crop Improvement and Regulation & College of Agronomy, Hebei Agricultural University, Baoding, Hebei 071001, China
| | - Lu Li
- State Key Laboratory of Plant Physiology and Biochemistry, Engineering Research Center of Plant Growth Regulator, Ministry of Education & College of Agronomy and Biotechnology, China Agricultural University, No.2 Yuanmingyuan West Road, Haidian, Beijing 100193, China
| | - Xing Wang
- State Key Laboratory of Plant Physiology and Biochemistry, Engineering Research Center of Plant Growth Regulator, Ministry of Education & College of Agronomy and Biotechnology, China Agricultural University, No.2 Yuanmingyuan West Road, Haidian, Beijing 100193, China
| | - Yuyi Zhou
- State Key Laboratory of Plant Physiology and Biochemistry, Engineering Research Center of Plant Growth Regulator, Ministry of Education & College of Agronomy and Biotechnology, China Agricultural University, No.2 Yuanmingyuan West Road, Haidian, Beijing 100193, China
| | - Mingcai Zhang
- State Key Laboratory of Plant Physiology and Biochemistry, Engineering Research Center of Plant Growth Regulator, Ministry of Education & College of Agronomy and Biotechnology, China Agricultural University, No.2 Yuanmingyuan West Road, Haidian, Beijing 100193, China
| | - Zhaohu Li
- State Key Laboratory of Plant Physiology and Biochemistry, Engineering Research Center of Plant Growth Regulator, Ministry of Education & College of Agronomy and Biotechnology, China Agricultural University, No.2 Yuanmingyuan West Road, Haidian, Beijing 100193, China
| | - Fei Yi
- State Key Laboratory of Plant Physiology and Biochemistry, Engineering Research Center of Plant Growth Regulator, Ministry of Education & College of Agronomy and Biotechnology, China Agricultural University, No.2 Yuanmingyuan West Road, Haidian, Beijing 100193, China
| | - Liusheng Duan
- State Key Laboratory of Plant Physiology and Biochemistry, Engineering Research Center of Plant Growth Regulator, Ministry of Education & College of Agronomy and Biotechnology, China Agricultural University, No.2 Yuanmingyuan West Road, Haidian, Beijing 100193, China
- College of Plant Science and Technology, Beijing University of Agriculture, Beijing, 102206, China
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Rafiei N, Ronceret A. Crossover interference mechanism: New lessons from plants. Front Cell Dev Biol 2023; 11:1156766. [PMID: 37274744 PMCID: PMC10236007 DOI: 10.3389/fcell.2023.1156766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 04/17/2023] [Indexed: 06/06/2023] Open
Abstract
Plants are the source of our understanding of several fundamental biological principles. It is well known that Gregor Mendel discovered the laws of Genetics in peas and that maize was used for the discovery of transposons by Barbara McClintock. Plant models are still useful for the understanding of general key biological concepts. In this article, we will focus on discussing the recent plant studies that have shed new light on the mysterious mechanisms of meiotic crossover (CO) interference, heterochiasmy, obligatory CO, and CO homeostasis. Obligatory CO is necessary for the equilibrated segregation of homologous chromosomes during meiosis. The tight control of the different male and female CO rates (heterochiasmy) enables both the maximization and minimization of genome shuffling. An integrative model can now predict these observed aspects of CO patterning in plants. The mechanism proposed considers the Synaptonemal Complex as a canalizing structure that allows the diffusion of a class I CO limiting factor linearly on synapsed bivalents. The coarsening of this limiting factor along the SC explains the interfering spacing between COs. The model explains the observed coordinated processes between synapsis, CO interference, CO insurance, and CO homeostasis. It also easily explains heterochiasmy just considering the different male and female SC lengths. This mechanism is expected to be conserved in other species.
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Steckenborn S, Cuacos M, Ayoub MA, Feng C, Schubert V, Hoffie I, Hensel G, Kumlehn J, Heckmann S. The meiotic topoisomerase VI B subunit (MTOPVIB) is essential for meiotic DNA double-strand break formation in barley (Hordeum vulgare L.). PLANT REPRODUCTION 2023; 36:1-15. [PMID: 35767067 PMCID: PMC9957907 DOI: 10.1007/s00497-022-00444-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 05/31/2022] [Indexed: 06/01/2023]
Abstract
In barley (Hordeum vulgare), MTOPVIB is critical for meiotic DSB and accompanied SC and CO formation while dispensable for meiotic bipolar spindle formation. Homologous recombination during meiosis assures genetic variation in offspring. Programmed meiotic DNA double-strand breaks (DSBs) are repaired as crossover (CO) or non-crossover (NCO) during meiotic recombination. The meiotic topoisomerase VI (TopoVI) B subunit (MTOPVIB) plays an essential role in meiotic DSB formation critical for CO-recombination. More recently MTOPVIB has been also shown to play a role in meiotic bipolar spindle formation in rice and maize. Here, we describe a meiotic DSB-defective mutant in barley (Hordeum vulgare L.). CRISPR-associated 9 (Cas9) endonuclease-generated mtopVIB plants show complete sterility due to the absence of meiotic DSB, synaptonemal complex (SC), and CO formation leading to the occurrence of univalents and their unbalanced segregation into aneuploid gametes. In HvmtopVIB plants, we also frequently found the bi-orientation of sister kinetochores in univalents during metaphase I and the precocious separation of sister chromatids during anaphase I. Moreover, the near absence of polyads after meiosis II, suggests that despite being critical for meiotic DSB formation in barley, MTOPVIB seems not to be strictly required for meiotic bipolar spindle formation.
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Affiliation(s)
- Stefan Steckenborn
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) OT Gatersleben, Corrensstrasse 3, 06466, Seeland, Germany
| | - Maria Cuacos
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) OT Gatersleben, Corrensstrasse 3, 06466, Seeland, Germany
| | - Mohammad A Ayoub
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) OT Gatersleben, Corrensstrasse 3, 06466, Seeland, Germany
| | - Chao Feng
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) OT Gatersleben, Corrensstrasse 3, 06466, Seeland, Germany
| | - Veit Schubert
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) OT Gatersleben, Corrensstrasse 3, 06466, Seeland, Germany
| | - Iris Hoffie
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) OT Gatersleben, Corrensstrasse 3, 06466, Seeland, Germany
| | - Götz Hensel
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) OT Gatersleben, Corrensstrasse 3, 06466, Seeland, Germany
| | - Jochen Kumlehn
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) OT Gatersleben, Corrensstrasse 3, 06466, Seeland, Germany
| | - Stefan Heckmann
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) OT Gatersleben, Corrensstrasse 3, 06466, Seeland, Germany.
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Synthetic apomixis: the beginning of a new era. Curr Opin Biotechnol 2023; 79:102877. [PMID: 36628906 DOI: 10.1016/j.copbio.2022.102877] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 11/24/2022] [Accepted: 12/05/2022] [Indexed: 01/11/2023]
Abstract
Apomixis is a process of asexual reproduction that enables plants to bypass meiosis and fertilization to generate clonal seeds that are identical to the maternal genotype. Apomixis has tremendous potential for breeding plants with desired characteristics, given its ability to fix any elite genotype. However, little is known about the origin and dynamics of natural apomictic plant systems. The introgression of apomixis-related genes from natural apomicts has achieved limited success. Therefore, synthetic apomixis, engineered to include apomeiosis, autonomous embryo formation, and autonomous endosperm development, has been proposed as a promising platform to effectuate apomixis in any crop. In this study, we have summarized recent advances in the understanding of synthetic apomixis and discussed the limitations of current synthetic apomixis systems and ways to overcome them.
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11
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Hyde L, Osman K, Winfield M, Sanchez‐Moran E, Higgins JD, Henderson IR, Sparks C, Franklin FCH, Edwards KJ. Identification, characterization, and rescue of CRISPR/Cas9 generated wheat SPO11-1 mutants. PLANT BIOTECHNOLOGY JOURNAL 2023; 21:405-418. [PMID: 36373224 PMCID: PMC9884015 DOI: 10.1111/pbi.13961] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 10/31/2022] [Accepted: 11/07/2022] [Indexed: 05/29/2023]
Abstract
Increasing crop yields through plant breeding is time consuming and laborious, with the generation of novel combinations of alleles being limited by chromosomal linkage blocks and linkage-drag. Meiotic recombination is essential to create novel genetic variation via the reshuffling of parental alleles. The exchange of genetic information between homologous chromosomes occurs at crossover (CO) sites but CO frequency is often low and unevenly distributed. This bias creates the problem of linkage-drag in recombination 'cold' regions, where undesirable variation remains linked to useful traits. In plants, programmed meiosis-specific DNA double-strand breaks, catalysed by the SPO11 complex, initiate the recombination pathway, although only ~5% result in the formation of COs. To study the role of SPO11-1 in wheat meiosis, and as a prelude to manipulation, we used CRISPR/Cas9 to generate edits in all three SPO11-1 homoeologues of hexaploid wheat. Characterization of progeny lines shows plants deficient in all six SPO11-1 copies fail to undergo chromosome synapsis, lack COs and are sterile. In contrast, lines carrying a single copy of any one of the three wild-type homoeologues are phenotypically indistinguishable from unedited plants both in terms of vegetative growth and fertility. However, cytogenetic analysis of the edited plants suggests that homoeologues differ in their ability to generate COs and in the dynamics of synapsis. In addition, we show that the transformation of wheat mutants carrying six edited copies of SPO11-1 with the TaSPO11-1B gene, restores synapsis, CO formation, and fertility and hence opens a route to modifying recombination in this agronomically important crop.
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Affiliation(s)
- Lucy Hyde
- School of Biological Sciences, Life SciencesUniversity of BristolBristolUK
| | - Kim Osman
- School of BiosciencesUniversity of BirminghamBirminghamUK
| | - Mark Winfield
- School of Biological Sciences, Life SciencesUniversity of BristolBristolUK
| | | | - James D. Higgins
- Department of Genetics and Genome BiologyUniversity of LeicesterLeicesterUK
| | | | | | | | - Keith J. Edwards
- School of Biological Sciences, Life SciencesUniversity of BristolBristolUK
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12
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Li M, Li S, He Y, Wang Y, Zhang T, Li P, He Y. ZmSPO11-2 is critical for meiotic recombination in maize. Chromosome Res 2022; 30:415-428. [PMID: 35674907 DOI: 10.1007/s10577-022-09694-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 04/13/2022] [Accepted: 04/15/2022] [Indexed: 01/25/2023]
Abstract
Most plant species have three or more SPO11/TOPOVIA homologs and two TOPOVIB homologs, which associate to trigger meiotic double-strand break (DSB) formation and subsequent meiotic recombination. In Zea mays L. (maize), ZmSPO11-1 and ZmMTOPVIB have been reported to be indispensable for the initiation of meiotic recombination, yet the function of ZmSPO11-2 remains unclear. In this study, we characterized meiotic functions of ZmSPO11-2 during male meiosis in maize. Two independent Zmspo11-1 knock-out mutants exhibited normal vegetative growth but both male and female sterility. The formation of meiotic DSBs of DNA molecules was fully abolished in the Zmspo11-2 plants, leading to the defective homologous chromosome paring, synapsis, recombination, and segregation. However, the bipolar spindle assembly was not noticeably affected in Zmspo11-2 meiocytes. Overall, our results demonstrate that as its partner ZmSPO11-1 and ZmMTOPVIB, ZmSPO11-2 plays essential roles in DSB formation and homologous recombination in maize meiosis.
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Affiliation(s)
- Menghan Li
- MOE Key Laboratory of Crop Heterosis and Utilization, National Maize Improvement Center of China, China Agricultural University, Beijing, 100094, China.,College of Plant Science, Tibet Agricultural and Animal Husbandry University, Nyingchi, 860000, China
| | - Shuyue Li
- MOE Key Laboratory of Crop Heterosis and Utilization, National Maize Improvement Center of China, China Agricultural University, Beijing, 100094, China
| | - Yan He
- College of Plant Science, Tibet Agricultural and Animal Husbandry University, Nyingchi, 860000, China
| | - Yan Wang
- MOE Key Laboratory of Crop Heterosis and Utilization, National Maize Improvement Center of China, China Agricultural University, Beijing, 100094, China
| | - Ting Zhang
- MOE Key Laboratory of Crop Heterosis and Utilization, National Maize Improvement Center of China, China Agricultural University, Beijing, 100094, China
| | - Ping Li
- College of Plant Science, Tibet Agricultural and Animal Husbandry University, Nyingchi, 860000, China.
| | - Yan He
- MOE Key Laboratory of Crop Heterosis and Utilization, National Maize Improvement Center of China, China Agricultural University, Beijing, 100094, China.
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13
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Brinkmeier J, Coelho S, de Massy B, Bourbon HM. Evolution and Diversity of the TopoVI and TopoVI-like Subunits With Extensive Divergence of the TOPOVIBL subunit. Mol Biol Evol 2022; 39:msac227. [PMID: 36256608 PMCID: PMC9665070 DOI: 10.1093/molbev/msac227] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Type II DNA topoisomerases regulate topology by double-stranded DNA cleavage and ligation. The TopoVI family of DNA topoisomerase, first identified and biochemically characterized in Archaea, represents, with TopoVIII and mini-A, the type IIB family. TopoVI has several intriguing features in terms of function and evolution. TopoVI has been identified in some eukaryotes, and a global view is lacking to understand its evolutionary pattern. In addition, in eukaryotes, the two TopoVI subunits (TopoVIA and TopoVIB) have been duplicated and have evolved to give rise to Spo11 and TopoVIBL, forming TopoVI-like (TopoVIL), a complex essential for generating DNA breaks that initiate homologous recombination during meiosis. TopoVIL is essential for sexual reproduction. How the TopoVI subunits have evolved to ensure this meiotic function is unclear. Here, we investigated the phylogenetic conservation of TopoVI and TopoVIL. We demonstrate that BIN4 and RHL1, potentially interacting with TopoVIB, have co-evolved with TopoVI. Based on model structures, this observation supports the hypothesis for a role of TopoVI in decatenation of replicated chromatids and predicts that in eukaryotes the TopoVI catalytic complex includes BIN4 and RHL1. For TopoVIL, the phylogenetic analysis of Spo11, which is highly conserved among Eukarya, highlighted a eukaryal-specific N-terminal domain that may be important for its regulation. Conversely, TopoVIBL was poorly conserved, giving rise to ATP hydrolysis-mutated or -truncated protein variants, or was undetected in some species. This remarkable plasticity of TopoVIBL provides important information for the activity and function of TopoVIL during meiosis.
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Affiliation(s)
- Julia Brinkmeier
- Institut de Génétique Humaine (IGH), Centre National de la Recherche Scientifique, Univ Montpellier, Montpellier 34396, France
| | - Susana Coelho
- Max Planck Institute for Developmental Biology, Tübingen 72076, Germany
| | - Bernard de Massy
- Institut de Génétique Humaine (IGH), Centre National de la Recherche Scientifique, Univ Montpellier, Montpellier 34396, France
| | - Henri-Marc Bourbon
- Centre de Biologie Intégrative, CNRS, Université de Toulouse, Toulouse 31400, France
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Multi-color dSTORM microscopy in Hormad1-/- spermatocytes reveals alterations in meiotic recombination intermediates and synaptonemal complex structure. PLoS Genet 2022; 18:e1010046. [PMID: 35857787 PMCID: PMC9342782 DOI: 10.1371/journal.pgen.1010046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 08/01/2022] [Accepted: 06/15/2022] [Indexed: 12/05/2022] Open
Abstract
Recombinases RAD51 and its meiosis-specific paralog DMC1 accumulate on single-stranded DNA (ssDNA) of programmed DNA double strand breaks (DSBs) in meiosis. Here we used three-color dSTORM microscopy, and a mouse model with severe defects in meiotic DSB formation and synapsis (Hormad1-/-) to obtain more insight in the recombinase accumulation patterns in relation to repair progression. First, we used the known reduction in meiotic DSB frequency in Hormad1-/- spermatocytes to be able to conclude that the RAD51/DMC1 nanofoci that preferentially localize at distances of ~300 nm form within a single DSB site, whereas a second preferred distance of ~900 nm, observed only in wild type, represents inter-DSB distance. Next, we asked whether the proposed role of HORMAD1 in repair inhibition affects the RAD51/DMC1 accumulation patterns. We observed that the two most frequent recombinase configurations (1 DMC1 and 1 RAD51 nanofocus (D1R1), and D2R1) display coupled frequency dynamics over time in wild type, but were constant in the Hormad1-/- model, indicating that the lifetime of these intermediates was altered. Recombinase nanofoci were also smaller in Hormad1-/- spermatocytes, consistent with changes in ssDNA length or protein accumulation. Furthermore, we established that upon synapsis, recombinase nanofoci localized closer to the synaptonemal complex (SYCP3), in both wild type and Hormad1-/- spermatocytes. Finally, the data also revealed a hitherto unknown function of HORMAD1 in inhibiting coil formation in the synaptonemal complex. SPO11 plays a similar but weaker role in coiling and SYCP1 had the opposite effect. Using this large super-resolution dataset, we propose models with the D1R1 configuration representing one DSB end containing recombinases, and the other end bound by other ssDNA binding proteins, or both ends loaded by the two recombinases, but in below-resolution proximity. This may then often evolve into D2R1, then D1R2, and finally back to D1R1, when DNA synthesis has commenced. In order to correctly pair homologous chromosomes in the first meiotic prophase, repair of programmed double strand breaks (DSBs) is essential. By unravelling molecular details of the protein assemblies at single DSBs, using super-resolution microscopy, we aim to understand the dynamics of repair intermediates and their functions. We investigated the localization of the two recombinases RAD51 and DMC1 in wild type and HORMAD1-deficient cells. HORMAD1 is involved in multiple aspects of homologous chromosome association: it regulates formation and repair of DSBs, and it stimulates formation of the synaptonemal complex (SC), the macromolecular protein assembly that connects paired chromosomes. RAD51 and DMC1 enable chromosome pairing by promoting the invasions of the intact chromatids by single-stranded DNA ends that result from DSBs. We found that in absence of HORMAD1, RAD51 and DMC1 showed small but significant morphological and positional changes, combined with altered kinetics of specific RAD51/DMC1 configurations. We also determined that there is a generally preferred distance of ~900 nm between meiotic DSBs along the SC. Finally, we observed changes in the structure of the SC in Hormad1-/- spermatocytes. This study contributes to a better understanding of the molecular details of meiotic homologous recombination and the role of HORMAD1 in meiotic prophase.
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15
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Differentiated function and localisation of SPO11-1 and PRD3 on the chromosome axis during meiotic DSB formation in Arabidopsis thaliana. PLoS Genet 2022; 18:e1010298. [PMID: 35857772 PMCID: PMC9342770 DOI: 10.1371/journal.pgen.1010298] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 08/01/2022] [Accepted: 06/16/2022] [Indexed: 11/19/2022] Open
Abstract
During meiosis, DNA double-strand breaks (DSBs) occur throughout the genome, a subset of which are repaired to form reciprocal crossovers between chromosomes. Crossovers are essential to ensure balanced chromosome segregation and to create new combinations of genetic variation. Meiotic DSBs are formed by a topoisomerase-VI-like complex, containing catalytic (e.g. SPO11) proteins and auxiliary (e.g. PRD3) proteins. Meiotic DSBs are formed in chromatin loops tethered to a linear chromosome axis, but the interrelationship between DSB-promoting factors and the axis is not fully understood. Here, we study the localisation of SPO11-1 and PRD3 during meiosis, and investigate their respective functions in relation to the chromosome axis. Using immunocytogenetics, we observed that the localisation of SPO11-1 overlaps relatively weakly with the chromosome axis and RAD51, a marker of meiotic DSBs, and that SPO11-1 recruitment to chromatin is genetically independent of the axis. In contrast, PRD3 localisation correlates more strongly with RAD51 and the chromosome axis. This indicates that PRD3 likely forms a functional link between SPO11-1 and the chromosome axis to promote meiotic DSB formation. We also uncovered a new function of SPO11-1 in the nucleation of the synaptonemal complex protein ZYP1. We demonstrate that chromosome co-alignment associated with ZYP1 deposition can occur in the absence of DSBs, and is dependent on SPO11-1, but not PRD3. Lastly, we show that the progression of meiosis is influenced by the presence of aberrant chromosomal connections, but not by the absence of DSBs or synapsis. Altogether, our study provides mechanistic insights into the control of meiotic DSB formation and reveals diverse functional interactions between SPO11-1, PRD3 and the chromosome axis. Most eukaryotes rely on the formation of gametes with half the number of chromosomes for sexual reproduction. Meiosis is a specialised type of cell division essential for the transition between a diploid and a haploid stage during gametogenesis. In early meiosis, programmed-DNA double strand breaks (DSBs) occur across the genome. These DSBs are processed by a set of proteins and the broken ends are repaired using the genetic information from the homologous chromosomes. These reciprocal exchanges of information between two chromosomes are called crossovers. Crossovers physical link chromosomes in pairs which is essential to ensure their correct segregation during the two rounds of meiotic division. Crossovers are also essential for the creation of genetic diversity as they break genetic linkages to form novel allelic blocks. The formation of DSBs is not completely understood in plants. Here we studied the function of SPO11-1 and PRD3, two proteins involved in the formation of DSBs in Arabidopsis. We discovered functional differences in their respective mode of recruitment to the chromosomes, their interactions with proteins forming the chromosome core and their roles in chromosome co-alignment. These indicate that, although SPO11-1 and PRD3 share a role in the formation of DSBs, the two proteins have additional and distinct roles beside DSB formation.
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16
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Wang Y, Wang Y, Zang J, Chen H, He Y. ZmPRD1 is essential for double-strand break formation, but is not required for bipolar spindle assembly during maize meiosis. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:3386-3400. [PMID: 35201286 DOI: 10.1093/jxb/erac075] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 02/23/2022] [Indexed: 06/14/2023]
Abstract
Homologs of PUTATIVE RECOMBINATION INITIATION DEFECT 1 (PRD1) are known to be essential for meiotic double-strand break (DSB) formation in mouse (Mus musculus), Arabidopsis, and rice (Oryza sativa). Recent research has shown that rice PRD1 also plays an unanticipated role in meiotic bipolar spindle assembly, revealing that PRD1 has multiple functions in plant meiosis. In this study, we characterize the meiotic function of PRD1 in maize (Zea mays; ZmPRD1). Our results show that Zmprd1 mutant plants display normal vegetative growth but have complete male and female sterility. Meiotic DSB formation is fully abolished in mutant meiocytes, leading to failure in homologous pairing, synapsis, and recombination. ZmPRD1 exhibits a different pattern of chromosome localization compared to its rice homologs. The ZmPRD1 protein interacts with several DSB-forming proteins, but does not directly interact with the kinetochore proteins REC8 and SGO1. Possibly as a result of this, there are no significant abnormalities of bipolar spindle assembly in Zmprd1 meiocytes. Overall, our results demonstrate that ZmPRD1 is essential for DSB formation and homologous recombination in maize meiosis. However, the recently-identified function of PRD1 in bipolar spindle assembly during rice meiosis is not conserved in maize.
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Affiliation(s)
- Yazhong Wang
- MOE Key Laboratory of Crop Heterosis and Utilization, National Maize Improvement Center of China, China Agricultural University, Beijing, China
| | - Yan Wang
- MOE Key Laboratory of Crop Heterosis and Utilization, National Maize Improvement Center of China, China Agricultural University, Beijing, China
| | - Jie Zang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Innovative Academy of Seed Design, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Huabang Chen
- State Key Laboratory of Plant Cell and Chromosome Engineering, Innovative Academy of Seed Design, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yan He
- MOE Key Laboratory of Crop Heterosis and Utilization, National Maize Improvement Center of China, China Agricultural University, Beijing, China
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17
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Vrielynck N, Schneider K, Rodriguez M, Sims J, Chambon A, Hurel A, De Muyt A, Ronceret A, Krsicka O, Mézard C, Schlögelhofer P, Grelon M. Conservation and divergence of meiotic DNA double strand break forming mechanisms in Arabidopsis thaliana. Nucleic Acids Res 2021; 49:9821-9835. [PMID: 34458909 PMCID: PMC8464057 DOI: 10.1093/nar/gkab715] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 07/16/2021] [Accepted: 08/04/2021] [Indexed: 11/13/2022] Open
Abstract
In the current meiotic recombination initiation model, the SPO11 catalytic subunits associate with MTOPVIB to form a Topoisomerase VI-like complex that generates DNA double strand breaks (DSBs). Four additional proteins, PRD1/AtMEI1, PRD2/AtMEI4, PRD3/AtMER2 and the plant specific DFO are required for meiotic DSB formation. Here we show that (i) MTOPVIB and PRD1 provide the link between the catalytic sub-complex and the other DSB proteins, (ii) PRD3/AtMER2, while localized to the axis, does not assemble a canonical pre-DSB complex but establishes a direct link between the DSB-forming and resection machineries, (iii) DFO controls MTOPVIB foci formation and is part of a divergent RMM-like complex including PHS1/AtREC114 and PRD2/AtMEI4 but not PRD3/AtMER2, (iv) PHS1/AtREC114 is absolutely unnecessary for DSB formation despite having a conserved position within the DSB protein network and (v) MTOPVIB and PRD2/AtMEI4 interact directly with chromosome axis proteins to anchor the meiotic DSB machinery to the axis.
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Affiliation(s)
- Nathalie Vrielynck
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, 78000 Versailles, France
| | - Katja Schneider
- Department of Chromosome Biology, Max Perutz Labs, University of Vienna, Vienna Biocenter, Dr. Bohr-Gasse 9, 1030 Vienna, Austria
| | - Marion Rodriguez
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, 78000 Versailles, France
| | - Jason Sims
- Department of Chromosome Biology, Max Perutz Labs, University of Vienna, Vienna Biocenter, Dr. Bohr-Gasse 9, 1030 Vienna, Austria
| | - Aurélie Chambon
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, 78000 Versailles, France
| | - Aurélie Hurel
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, 78000 Versailles, France
| | - Arnaud De Muyt
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, 78000 Versailles, France
| | - Arnaud Ronceret
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, 78000 Versailles, France
| | - Ondrej Krsicka
- Department of Chromosome Biology, Max Perutz Labs, University of Vienna, Vienna Biocenter, Dr. Bohr-Gasse 9, 1030 Vienna, Austria
| | - Christine Mézard
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, 78000 Versailles, France
| | - Peter Schlögelhofer
- Department of Chromosome Biology, Max Perutz Labs, University of Vienna, Vienna Biocenter, Dr. Bohr-Gasse 9, 1030 Vienna, Austria
| | - Mathilde Grelon
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, 78000 Versailles, France
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18
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Gutiérrez Pinzón Y, González Kise JK, Rueda P, Ronceret A. The Formation of Bivalents and the Control of Plant Meiotic Recombination. FRONTIERS IN PLANT SCIENCE 2021; 12:717423. [PMID: 34557215 PMCID: PMC8453087 DOI: 10.3389/fpls.2021.717423] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Accepted: 08/13/2021] [Indexed: 06/06/2023]
Abstract
During the first meiotic division, the segregation of homologous chromosomes depends on the physical association of the recombined homologous DNA molecules. The physical tension due to the sites of crossing-overs (COs) is essential for the meiotic spindle to segregate the connected homologous chromosomes to the opposite poles of the cell. This equilibrated partition of homologous chromosomes allows the first meiotic reductional division. Thus, the segregation of homologous chromosomes is dependent on their recombination. In this review, we will detail the recent advances in the knowledge of the mechanisms of recombination and bivalent formation in plants. In plants, the absence of meiotic checkpoints allows observation of subsequent meiotic events in absence of meiotic recombination or defective meiotic chromosomal axis formation such as univalent formation instead of bivalents. Recent discoveries, mainly made in Arabidopsis, rice, and maize, have highlighted the link between the machinery of double-strand break (DSB) formation and elements of the chromosomal axis. We will also discuss the implications of what we know about the mechanisms regulating the number and spacing of COs (obligate CO, CO homeostasis, and interference) in model and crop plants.
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Lenykó-Thegze A, Fábián A, Mihók E, Makai D, Cseh A, Sepsi A. Pericentromeric chromatin reorganisation follows the initiation of recombination and coincides with early events of synapsis in cereals. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 107:1585-1602. [PMID: 34171148 DOI: 10.1111/tpj.15391] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 06/04/2021] [Accepted: 06/14/2021] [Indexed: 06/13/2023]
Abstract
The reciprocal exchange of genetic information between homologous chromosomes during meiotic recombination is essential to secure balanced chromosome segregation and to promote genetic diversity. The chromosomal position and frequency of reciprocal genetic exchange shapes the efficiency of breeding programmes and influences crop improvement under a changing climate. In large genome cereals, such as wheat and barley, crossovers are consistently restricted to subtelomeric chromosomal regions, thus preventing favourable allele combinations being formed within a considerable proportion of the genome, including interstitial and pericentromeric chromatin. Understanding the key elements driving crossover designation is therefore essential to broaden the regions available for crossovers. Here, we followed early meiotic chromatin dynamism in cereals through the visualisation of a homologous barley chromosome arm pair stably transferred into the wheat genetic background. By capturing the dynamics of a single chromosome arm at the same time as detecting the undergoing events of meiotic recombination and synapsis, we showed that subtelomeric chromatin of homologues synchronously transitions to an open chromatin structure during recombination initiation. By contrast, pericentromeric and interstitial regions preserved their closed chromatin organisation and become unpackaged only later, concomitant with initiation of recombinatorial repair and the initial assembly of the synaptonemal complex. Our results raise the possibility that the closed pericentromeric chromatin structure in cereals may influence the fate decision during recombination initiation, as well as the spatial development of synapsis, and may also explain the suppression of crossover events in the proximity of the centromeres.
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Affiliation(s)
- Andrea Lenykó-Thegze
- Department of Biological Resources, Eötvös Loránd Research Network, Centre for Agricultural Research, Brunszvik u. 2, Martonvásár, 2462, Hungary
| | - Attila Fábián
- Department of Biological Resources, Eötvös Loránd Research Network, Centre for Agricultural Research, Brunszvik u. 2, Martonvásár, 2462, Hungary
| | - Edit Mihók
- Department of Biological Resources, Eötvös Loránd Research Network, Centre for Agricultural Research, Brunszvik u. 2, Martonvásár, 2462, Hungary
| | - Diána Makai
- Department of Biological Resources, Eötvös Loránd Research Network, Centre for Agricultural Research, Brunszvik u. 2, Martonvásár, 2462, Hungary
| | - András Cseh
- Department of Molecular Breeding, Eötvös Loránd Research Network, Centre for Agricultural Research, Brunszvik u. 2, Martonvásár, 2462, Hungary
| | - Adél Sepsi
- Department of Biological Resources, Eötvös Loránd Research Network, Centre for Agricultural Research, Brunszvik u. 2, Martonvásár, 2462, Hungary
- Department of Applied Biotechnology and Food Science (ABÉT), BME, Budapest University of Technology and Economics, Műegyetem rkp. 3-9, Budapest, 1111, Hungary
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20
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Sprink T, Hartung F. Heterologous Complementation of SPO11-1 and -2 Depends on the Splicing Pattern. Int J Mol Sci 2021; 22:ijms22179346. [PMID: 34502253 PMCID: PMC8430568 DOI: 10.3390/ijms22179346] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 08/20/2021] [Accepted: 08/23/2021] [Indexed: 11/16/2022] Open
Abstract
In the past, major findings in meiosis have been achieved, but questions towards the global understanding of meiosis remain concealed. In plants, one of these questions covers the need for two diverse meiotic active SPO11 proteins. In Arabidopsis and other plants, both meiotic SPO11 are indispensable in a functional form for double strand break induction during meiotic prophase I. This stands in contrast to mammals and fungi, where a single SPO11 is present and sufficient. We aimed to investigate the specific function and evolution of both meiotic SPO11 paralogs in land plants. By performing immunostaining of both SPO11-1 and -2, an investigation of the spatiotemporal localization of each SPO11 during meiosis was achieved. We further exchanged SPO11-1 and -2 in Arabidopsis and could show a species-specific function of the respective SPO11. By additional changes of regions between SPO11-1 and -2, a sequence-specific function for both the SPO11 proteins was revealed. Furthermore, the previous findings about the aberrant splicing of each SPO11 were refined by narrowing them down to a specific developmental phase. These findings let us suggest that the function of both SPO11 paralogs is highly sequence specific and that the orthologs are species specific.
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21
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Abstract
Meiotic recombination is a fundamental process that generates genetic diversity and ensures the accurate segregation of homologous chromosomes. While a great deal is known about genetic factors that regulate recombination, relatively little is known about epigenetic factors, such as DNA methylation. In maize, we examined the effects on meiotic recombination of a mutation in a component of the RNA-directed DNA methylation pathway, Mop1 (Mediator of paramutation1), as well as a mutation in a component of the trans-acting small interference RNA biogenesis pathway, Lbl1 (Leafbladeless1). MOP1 is of particular interest with respect to recombination because it is responsible for methylation of transposable elements that are immediately adjacent to transcriptionally active genes. In the mop1 mutant, we found that meiotic recombination is uniformly decreased in pericentromeric regions but is generally increased in gene rich chromosomal arms. This observation was further confirmed by cytogenetic analysis showing that although overall crossover numbers are unchanged, they occur more frequently in chromosomal arms in mop1 mutants. Using whole genome bisulfite sequencing, our data show that crossover redistribution is driven by loss of CHH (where H = A, T, or C) methylation within regions near genes. In contrast to what we observed in mop1 mutants, no significant changes were observed in the frequency of meiotic recombination in lbl1 mutants. Our data demonstrate that CHH methylation has a significant impact on the overall recombination landscape in maize despite its low frequency relative to CG and CHG methylation.
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Sims J, Schlögelhofer P, Kurzbauer MT. From Microscopy to Nanoscopy: Defining an Arabidopsis thaliana Meiotic Atlas at the Nanometer Scale. FRONTIERS IN PLANT SCIENCE 2021; 12:672914. [PMID: 34084178 PMCID: PMC8167036 DOI: 10.3389/fpls.2021.672914] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 04/27/2021] [Indexed: 06/12/2023]
Abstract
Visualization of meiotic chromosomes and the proteins involved in meiotic recombination have become essential to study meiosis in many systems including the model plant Arabidopsis thaliana. Recent advances in super-resolution technologies changed how microscopic images are acquired and analyzed. New technologies enable observation of cells and nuclei at a nanometer scale and hold great promise to the field since they allow observing complex meiotic molecular processes with unprecedented detail. Here, we provide an overview of classical and advanced sample preparation and microscopy techniques with an updated Arabidopsis meiotic atlas based on super-resolution microscopy. We review different techniques, focusing on stimulated emission depletion (STED) nanoscopy, to offer researchers guidance for selecting the optimal protocol and equipment to address their scientific question.
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Ren Z, Wang X, Tao Q, Guo Q, Zhou Y, Yi F, Huang G, Li Y, Zhang M, Li Z, Duan L. Transcriptome dynamic landscape underlying the improvement of maize lodging resistance under coronatine treatment. BMC PLANT BIOLOGY 2021; 21:202. [PMID: 33906598 PMCID: PMC8077928 DOI: 10.1186/s12870-021-02962-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 04/07/2021] [Indexed: 05/17/2023]
Abstract
BACKGROUND Lodging is one of the important factors causing maize yield. Plant height is an important factor in determining plant architecture in maize (Zea mays L.), which is closely related to lodging resistance under high planting density. Coronatine (COR), which is a phytotoxin and produced by the pathogen Pseudomonas syringae, is a functional and structural analogue of jasmonic acid (JA). RESULTS In this study, we found COR, as a new plant growth regulator, could effectively reduce plant height and ear height of both hybrids (ZD958 and XY335) and inbred (B73) maize by inhibiting internode growth during elongation, thus improve maize lodging resistance. To study gene expression changes in internode after COR treatment, we collected spatio-temporal transcriptome of inbred B73 internode under normal condition and COR treatment, including the three different regions of internode (fixed, meristem and elongation regions) at three different developmental stages. The gene expression levels of the three regions at normal condition were described and then compared with that upon COR treatment. In total, 8605 COR-responsive genes (COR-RGs) were found, consist of 802 genes specifically expressed in internode. For these COR-RGs, 614, 870, 2123 of which showed expression changes in only fixed, meristem and elongation region, respectively. Both the number and function were significantly changed for COR-RGs identified in different regions, indicating genes with different functions were regulated at the three regions. Besides, we found more than 80% genes of gibberellin and jasmonic acid were changed under COR treatment. CONCLUSIONS These data provide a gene expression profiling in different regions of internode development and molecular mechanism of COR affecting internode elongation. A putative schematic of the internode response to COR treatment is proposed which shows the basic process of COR affecting internode elongation. This research provides a useful resource for studying maize internode development and improves our understanding of the COR regulation mechanism based on plant height.
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Affiliation(s)
- Zhaobin Ren
- State Key Laboratory of Plant Physiology and Biochemistry, Engineering Research Center of Plant Growth Regulator, Ministry of Education &College of Agronomy and Biotechnology, China Agricultural University, No.2 Yuanmingyuan West Road, Haidian, Beijing, 100193, China
| | - Xing Wang
- State Key Laboratory of Plant Physiology and Biochemistry, Engineering Research Center of Plant Growth Regulator, Ministry of Education &College of Agronomy and Biotechnology, China Agricultural University, No.2 Yuanmingyuan West Road, Haidian, Beijing, 100193, China
| | - Qun Tao
- State Key Laboratory of Plant Physiology and Biochemistry, Engineering Research Center of Plant Growth Regulator, Ministry of Education &College of Agronomy and Biotechnology, China Agricultural University, No.2 Yuanmingyuan West Road, Haidian, Beijing, 100193, China
| | - Qing Guo
- State Key Laboratory of Plant Physiology and Biochemistry, Engineering Research Center of Plant Growth Regulator, Ministry of Education &College of Agronomy and Biotechnology, China Agricultural University, No.2 Yuanmingyuan West Road, Haidian, Beijing, 100193, China
| | - Yuyi Zhou
- State Key Laboratory of Plant Physiology and Biochemistry, Engineering Research Center of Plant Growth Regulator, Ministry of Education &College of Agronomy and Biotechnology, China Agricultural University, No.2 Yuanmingyuan West Road, Haidian, Beijing, 100193, China
| | - Fei Yi
- State Key Laboratory of Plant Physiology and Biochemistry, Engineering Research Center of Plant Growth Regulator, Ministry of Education &College of Agronomy and Biotechnology, China Agricultural University, No.2 Yuanmingyuan West Road, Haidian, Beijing, 100193, China.
| | - Guanmin Huang
- State Key Laboratory of Plant Physiology and Biochemistry, Engineering Research Center of Plant Growth Regulator, Ministry of Education &College of Agronomy and Biotechnology, China Agricultural University, No.2 Yuanmingyuan West Road, Haidian, Beijing, 100193, China
| | - Yanxia Li
- State Key Laboratory of Plant Physiology and Biochemistry, Engineering Research Center of Plant Growth Regulator, Ministry of Education &College of Agronomy and Biotechnology, China Agricultural University, No.2 Yuanmingyuan West Road, Haidian, Beijing, 100193, China
| | - Mingcai Zhang
- State Key Laboratory of Plant Physiology and Biochemistry, Engineering Research Center of Plant Growth Regulator, Ministry of Education &College of Agronomy and Biotechnology, China Agricultural University, No.2 Yuanmingyuan West Road, Haidian, Beijing, 100193, China
| | - Zhaohu Li
- State Key Laboratory of Plant Physiology and Biochemistry, Engineering Research Center of Plant Growth Regulator, Ministry of Education &College of Agronomy and Biotechnology, China Agricultural University, No.2 Yuanmingyuan West Road, Haidian, Beijing, 100193, China
| | - Liusheng Duan
- State Key Laboratory of Plant Physiology and Biochemistry, Engineering Research Center of Plant Growth Regulator, Ministry of Education &College of Agronomy and Biotechnology, China Agricultural University, No.2 Yuanmingyuan West Road, Haidian, Beijing, 100193, China.
- College of Plant Science and Technology, Beijing University of Agriculture, No.7 Beinong Road, Changping, Beijing, 102206, China.
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Jing JL, Zhang T, Kao YH, Huang TH, Wang CJR, He Y. ZmMTOPVIB Enables DNA Double-Strand Break Formation and Bipolar Spindle Assembly during Maize Meiosis. PLANT PHYSIOLOGY 2020; 184:1811-1822. [PMID: 33077613 PMCID: PMC7723106 DOI: 10.1104/pp.20.00933] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 10/01/2020] [Indexed: 05/17/2023]
Abstract
The meiotic TopoVI B subunit (MTopVIB) plays an essential role in double-strand break formation in mouse (Mus musculus), Arabidopsis (Arabidopsis thaliana), and rice (Oryza sativa), and recent work reveals that rice MTopVIB also plays an unexpected role in meiotic bipolar spindle assembly, highlighting multiple functions of MTopVIB during rice meiosis. In this work, we characterized the meiotic TopVIB in maize (Zea mays; ZmMTOPVIB). The ZmmtopVIB mutant plants exhibited normal vegetative growth but male and female sterility. Meiotic double-strand break formation was abolished in mutant meiocytes. Despite normal assembly of axial elements, mutants showed severely affected synapsis and disrupted homologous pairing. Importantly, we showed that bipolar spindle assembly was also affected in ZmmtopVIB, resulting in triad and polyad formation. Overall, our results demonstrate that ZmMTOPVIB plays critical roles in double-strand break formation and homologous recombination. In addition, our results suggest that the function of MTOPVIB in bipolar spindle assembly is likely conserved across different monocots.
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Affiliation(s)
- Ju-Li Jing
- Ministry of Education Key Laboratory of Crop Heterosis and Utilization, National Maize Improvement Center of China, College of Agronomy and Biotechnology, China Agricultural University, 100094 Beijing, China
| | - Ting Zhang
- Ministry of Education Key Laboratory of Crop Heterosis and Utilization, National Maize Improvement Center of China, College of Agronomy and Biotechnology, China Agricultural University, 100094 Beijing, China
| | - Yu-Hsin Kao
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Tzu-Han Huang
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | | | - Yan He
- Ministry of Education Key Laboratory of Crop Heterosis and Utilization, National Maize Improvement Center of China, College of Agronomy and Biotechnology, China Agricultural University, 100094 Beijing, China
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PCH-2 collaborates with CMT-1 to proofread meiotic homolog interactions. PLoS Genet 2020; 16:e1008904. [PMID: 32730253 PMCID: PMC7433886 DOI: 10.1371/journal.pgen.1008904] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 08/18/2020] [Accepted: 06/01/2020] [Indexed: 11/19/2022] Open
Abstract
The conserved ATPase, PCH-2/TRIP13, is required during both the spindle checkpoint and meiotic prophase. However, its specific role in regulating meiotic homolog pairing, synapsis and recombination has been enigmatic. Here, we report that this enzyme is required to proofread meiotic homolog interactions. We generated a mutant version of PCH-2 in C. elegans that binds ATP but cannot hydrolyze it: pch-2E253Q. In vitro, this mutant can bind a known substrate but is unable to remodel it. This mutation results in some non-homologous synapsis and impaired crossover assurance. Surprisingly, worms with a null mutation in PCH-2's adapter protein, CMT-1, the ortholog of p31comet, localize PCH-2 to meiotic chromosomes, exhibit non-homologous synapsis and lose crossover assurance. The similarity in phenotypes between cmt-1 and pch-2E253Q mutants suggest that PCH-2 can bind its meiotic substrates in the absence of CMT-1, in contrast to its role during the spindle checkpoint, but requires its adapter to hydrolyze ATP and remodel them.
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Juranić M, Nagahatenna DSK, Salinas-Gamboa R, Hand ML, Sánchez-León N, Leong WH, How T, Bazanova N, Spriggs A, Vielle-Calzada JP, Koltunow AMG. A detached leaf assay for testing transient gene expression and gene editing in cowpea ( Vigna unguiculata [L.] Walp.). PLANT METHODS 2020; 16:88. [PMID: 32549904 PMCID: PMC7296760 DOI: 10.1186/s13007-020-00630-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 06/06/2020] [Indexed: 05/19/2023]
Abstract
BACKGROUND The legume cowpea (Vigna unguiculata L.) is extensively grown in sub-Saharan Africa. Cowpea, like many legumes has proved recalcitrant to plant transformation. A rapid transient leaf assay was developed for testing gene expression and editing constructs prior to stable cowpea transformation, to accelerate cowpea and legume crop improvement. RESULTS Attempts to develop a transient protoplast system for cowpea were unsuccessful. Leaflets from plants 3-4 weeks post-germination were age selected to establish a rapid Agrobacterium (Agro) infiltration-mediated transient system for efficacy testing of gene expression and CRISPR/Cas9 gene editing constructs. In planta, Agro-infiltration of leaflets with fluorescent expression constructs, resulted in necrosis. By contrast, Agro-infiltration of detached leaflets with an Arabidopsis (At) ubiquitin3 promoter:ZsGreen construct, followed by culture on solid nutrient medium resulted in fluorescence in over 48% of leaf cells. Expression efficiency was leaf age-dependent. Three cowpea meiosis genes were identified for CRISPR/Cas9 gene-editing, with the forward aim of meiosis-knock out for asexual seed induction in cowpea. Constructs were designed and tested containing candidate gene-specific guide RNAs, expressed using either the cowpea or Arabidopsis U6 promoters with Cas9 expression directed by either the Arabidopsis 40S ribosomal protein or parsley ubiquitin4-2 promoters. Leaflets were infiltrated with test gene-editing constructs and analytical methods developed to identify gene-specific mutations. A construct that produced mutations predicted to induce functional knockout of in the VuSPO11-1 meiosis gene was tested for efficacy in primary transgenic cowpea plants using a previously established stable transformation protocol. Vuspo11-1 mutants were identified, that cytologically phenocopied spo11-1 mutants previously characterized in Arabidopsis, and rice. Importantly, a biallelic male and female sterile mutant was identified in primary transgenics, exhibiting the expected defects in 100% of examined male and female meiocytes. CONCLUSION The transient, detached cowpea leaf assay, and supporting analytical methods developed, provide a rapid and reproducible means for testing gene expression constructs, and constructs for inducing mutagenesis in genes involved in both vegetative and reproductive developmental programs. The method and tested editing constructs and components have potential application for a range of crop legumes.
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Affiliation(s)
- Martina Juranić
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Agriculture and Food, Urrbrae, SA 5064 Australia
| | - Dilrukshi S. K. Nagahatenna
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Agriculture and Food, Urrbrae, SA 5064 Australia
| | - Rigel Salinas-Gamboa
- Grupo de Desarrollo Reproductivo y Apomixis, UGA Laboratorio Nacional de Genómica para la Biodiversidad, CINVESTAV Irapuato, Guanajuato, Mexico
| | - Melanie L. Hand
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Agriculture and Food, Urrbrae, SA 5064 Australia
| | - Nidia Sánchez-León
- Grupo de Desarrollo Reproductivo y Apomixis, UGA Laboratorio Nacional de Genómica para la Biodiversidad, CINVESTAV Irapuato, Guanajuato, Mexico
| | - Weng Herng Leong
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Agriculture and Food, Urrbrae, SA 5064 Australia
| | - Tracy How
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Agriculture and Food, Urrbrae, SA 5064 Australia
| | - Natalia Bazanova
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Agriculture and Food, Urrbrae, SA 5064 Australia
| | - Andrew Spriggs
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Agriculture and Food, Black Mountain Laboratories, Canberra, ACT 2601 Australia
| | - Jean-Philippe Vielle-Calzada
- Grupo de Desarrollo Reproductivo y Apomixis, UGA Laboratorio Nacional de Genómica para la Biodiversidad, CINVESTAV Irapuato, Guanajuato, Mexico
| | - Anna M. G. Koltunow
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Agriculture and Food, Urrbrae, SA 5064 Australia
- Present Address: Centre for Crop Science, Queensland Alliance for Agriculture and Food Innovation (QAAFI), The University of Queensland, Brisbane, QLD 4072 Australia
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27
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Wang H, Xu W, Sun Y, Lian Q, Wang C, Yu C, He C, Wang J, Ma H, Copenhaver GP, Wang Y. The cohesin loader SCC2 contains a PHD finger that is required for meiosis in land plants. PLoS Genet 2020; 16:e1008849. [PMID: 32516352 PMCID: PMC7304647 DOI: 10.1371/journal.pgen.1008849] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 06/19/2020] [Accepted: 05/11/2020] [Indexed: 12/13/2022] Open
Abstract
Cohesin, a multisubunit protein complex, is required for holding sister chromatids together during mitosis and meiosis. The recruitment of cohesin by the sister chromatid cohesion 2/4 (SCC2/4) complex has been extensively studied in Saccharomyces cerevisiae mitosis, but its role in mitosis and meiosis remains poorly understood in multicellular organisms, because complete loss-of-function of either gene causes embryonic lethality. Here, we identified a weak allele of Atscc2 (Atscc2-5) that has only minor defects in vegetative development but exhibits a significant reduction in fertility. Cytological analyses of Atscc2-5 reveal multiple meiotic phenotypes including defects in chromosomal axis formation, meiosis-specific cohesin loading, homolog pairing and synapsis, and AtSPO11-1-dependent double strand break repair. Surprisingly, even though AtSCC2 interacts with AtSCC4 in vitro and in vivo, meiosis-specific knockdown of AtSCC4 expression does not cause any meiotic defect, suggesting that the SCC2-SCC4 complex has divergent roles in mitosis and meiosis. SCC2 homologs from land plants have a unique plant homeodomain (PHD) motif not found in other species. We show that the AtSCC2 PHD domain can bind to the N terminus of histones and is required for meiosis but not mitosis. Taken together, our results provide evidence that unlike SCC2 in other organisms, SCC2 requires a functional PHD domain during meiosis in land plants.
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Affiliation(s)
- Hongkuan Wang
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory of Biodiversity Sciences and Ecological Engineering, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, China
- Center for Epigenetics, Van Andel Institute, Grand Rapids, Michigan, United States of America
| | - Wanyue Xu
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory of Biodiversity Sciences and Ecological Engineering, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, China
| | - Yujin Sun
- Department of Biology and the Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Qichao Lian
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory of Biodiversity Sciences and Ecological Engineering, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, China
| | - Cong Wang
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory of Biodiversity Sciences and Ecological Engineering, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, China
| | - Chaoyi Yu
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory of Biodiversity Sciences and Ecological Engineering, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, China
| | - Chengpeng He
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory of Biodiversity Sciences and Ecological Engineering, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, China
| | - Jun Wang
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory of Biodiversity Sciences and Ecological Engineering, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, China
| | - Hong Ma
- Department of Biology, the Huck Institutes of the Life Sciences, the Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Gregory P. Copenhaver
- Department of Biology and the Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, North Carolina, United States of America
| | - Yingxiang Wang
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory of Biodiversity Sciences and Ecological Engineering, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, China
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