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Fernández-Jiménez N, Martinez-Garcia M, Varas J, Gil-Dones F, Santos JL, Pradillo M. The scaffold nucleoporins SAR1 and SAR3 are essential for proper meiotic progression in Arabidopsis thaliana. Front Cell Dev Biol 2023; 11:1285695. [PMID: 38111849 PMCID: PMC10725928 DOI: 10.3389/fcell.2023.1285695] [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: 08/30/2023] [Accepted: 11/21/2023] [Indexed: 12/20/2023] Open
Abstract
Nuclear Pore Complexes (NPCs) are embedded in the nuclear envelope (NE), regulating macromolecule transport and physically interacting with chromatin. The NE undergoes dramatic breakdown and reformation during plant cell division. In addition, this structure has a specific meiotic function, anchoring and positioning telomeres to facilitate the pairing of homologous chromosomes. To elucidate a possible function of the structural components of the NPCs in meiosis, we have characterized several Arabidopsis lines with mutations in genes encoding nucleoporins belonging to the outer ring complex. Plants defective for either SUPPRESSOR OF AUXIN RESISTANCE1 (SAR1, also called NUP160) or SAR3 (NUP96) present condensation abnormalities and SPO11-dependent chromosome fragmentation in a fraction of meiocytes, which is increased in the double mutant sar1 sar3. We also observed these meiotic defects in mutants deficient in the outer ring complex protein HOS1, but not in mutants affected in other components of this complex. Furthermore, our findings may suggest defects in the structure of NPCs in sar1 and a potential link between the meiotic role of this nucleoporin and a component of the RUBylation pathway. These results provide the first insights in plants into the role of nucleoporins in meiotic chromosome behavior.
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Affiliation(s)
- Nadia Fernández-Jiménez
- Department of Genetics, Physiology and Microbiology, Faculty of Biological Sciences, Universidad Complutense de Madrid, Madrid, Spain
| | - Marina Martinez-Garcia
- Department of Biotechnology-Plant Biology, School of Agricultural, Food and Biosystems Engineering, Universidad Politécnica de Madrid, Madrid, Spain
| | | | - Félix Gil-Dones
- Department of Genetics, Physiology and Microbiology, Faculty of Biological Sciences, Universidad Complutense de Madrid, Madrid, Spain
| | - Juan Luis Santos
- Department of Genetics, Physiology and Microbiology, Faculty of Biological Sciences, Universidad Complutense de Madrid, Madrid, Spain
| | - Mónica Pradillo
- Department of Genetics, Physiology and Microbiology, Faculty of Biological Sciences, Universidad Complutense de Madrid, Madrid, Spain
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2
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Gong T, McNally FJ. Caenorhabditis elegans spermatocytes can segregate achiasmate homologous chromosomes apart at higher than random frequency during meiosis I. Genetics 2023; 223:iyad021. [PMID: 36792551 PMCID: PMC10319977 DOI: 10.1093/genetics/iyad021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 02/05/2023] [Accepted: 02/07/2023] [Indexed: 02/17/2023] Open
Abstract
Chromosome segregation errors during meiosis are the leading cause of aneuploidy. Faithful chromosome segregation during meiosis in most eukaryotes requires a crossover which provides a physical attachment holding homologs together in a "bivalent." Crossovers are critical for homologs to be properly aligned and partitioned in the first meiotic division. Without a crossover, individual homologs (univalents) might segregate randomly, resulting in aneuploid progeny. However, Caenorhabditis elegans zim-2 mutants, which have crossover defects on chromosome V, have fewer dead embryos than that expected from random segregation. This deviation from random segregation is more pronounced in zim-2 males than that in females. We found three phenomena that can explain this apparent discrepancy. First, we detected crossovers on chromosome V in both zim-2(tm574) oocytes and spermatocytes, suggesting a redundant mechanism to make up for the ZIM-2 loss. Second, after accounting for the background crossover frequency, spermatocytes produced significantly more euploid gametes than what would be expected from random segregation. Lastly, trisomy of chromosome V is viable and fertile. Together, these three phenomena allow zim-2(tm574) mutants with reduced crossovers on chromosome V to have more viable progeny. Furthermore, live imaging of meiosis in spo-11(me44) oocytes and spermatocytes, which exhibit crossover failure on all 6 chromosomes, showed 12 univalents segregating apart in roughly equal masses in a homology-independent manner, supporting the existence of a mechanism that segregates any 2 chromosomes apart.
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Affiliation(s)
- Ting Gong
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616, USA
| | - Francis J McNally
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616, USA
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3
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Cuñado N. Surface Spreading Technique in Plant Meiocytes for Analysis of Synaptonemal Complex by Electron Microscopy. Methods Mol Biol 2020; 2061:181-196. [PMID: 31583660 DOI: 10.1007/978-1-4939-9818-0_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
An improved method of preparing two-dimensional surface spreads of synaptonemal complexes (SCs) in higher plants for examination by electron microscopy is described. This protocol produces clear, well-spread preparations of SCs and unpaired axial cores from a range of meiotic prophase I stages (leptotene to pachytene) from meiocytes of different plant species. Synaptonemal complex (SC) analyses have been widely used in plant cytogenetic studies to address the process of meiotic chromosome synapses, because of the high-resolution allowed by electron microscopy. Although the real role of SC is still enigmatic, its presence and structural conservation in the vast majority of organisms reflect the importance of this protein structure in the meiotic process.
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Affiliation(s)
- Nieves Cuñado
- Departamento de Genética, Fisiología y Microbiología, Facultad de Biología, Universidad Complutense de Madrid, Madrid, Spain.
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4
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Su S, Pan B, Hu Y, Wang M. Characterization of aminopeptidase encoding gene anp-1 and its association with development in Caenorhabditis elegans. PeerJ 2019; 7:e7944. [PMID: 31737443 PMCID: PMC6857582 DOI: 10.7717/peerj.7944] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 09/24/2019] [Indexed: 12/20/2022] Open
Abstract
Background Aminopeptidases play important roles in various biological processes in nematodes including growth, development and reproduction. Although the aminopeptidases have been shown to regulate reproduction in Caenorhabditis elegans (C. elegans), the role of aminopeptidases in development and aging has not been reported. This study focused on the function of aminopeptidase AlaNyl aminopeptidase 1 (ANP-1) on development in C. elegans. Methods In the present study, we reported the identification of ANP-1 in C. elegans along with sequence analysis and its functional expression and characterization. The phenotype changes were observed when anp-1 mutated. Then, differential expression genes (DEGs) between wild type strain (N2) and anp-1 deletion strain (RB804) were identified using transcriptome sequencing method. Finally, DEGs were verified by qRT-PCR assay. Results Our observations suggested that anp-1 mutation induced small body size in the L4/young adult stage of C. elegans, however, there was no difference between N2 and RB804 in adult stage. Moreover, deletion of anp-1 resulted in shortening lifespan and laying fewer eggs. DEGs (184 genes) were observed between N2 groups and RB804 groups by transcriptome sequencing. According to GO annotations and KEGG enrichment analysis, these DEGs play vital roles in development regulation in C. elegans. These data demonstrate ANP-1 participates in development and aging of C. elegans and will considerably contribute to the existing knowledge of aminopeptidase function in C. elegans.
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Affiliation(s)
- Shanchun Su
- Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, Beijing, China.,Institute of Anesthesiology and Pain (IAP), Taihe Hospital, Shiyan, Hubei, China
| | - Baoliang Pan
- Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, Beijing, China
| | - Yanxin Hu
- Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, Beijing, China
| | - Ming Wang
- Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, Beijing, China
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5
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Lee DH, Kao YH, Ku JC, Lin CY, Meeley R, Jan YS, Wang CJR. The Axial Element Protein DESYNAPTIC2 Mediates Meiotic Double-Strand Break Formation and Synaptonemal Complex Assembly in Maize. THE PLANT CELL 2015; 27:2516-29. [PMID: 26296964 PMCID: PMC4815100 DOI: 10.1105/tpc.15.00434] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 07/14/2015] [Accepted: 07/29/2015] [Indexed: 05/18/2023]
Abstract
During meiosis, homologous chromosomes pair and recombine via repair of programmed DNA double-strand breaks (DSBs). DSBs are formed in the context of chromatin loops, which are anchored to the proteinaceous axial element (AE). The AE later serves as a framework to assemble the synaptonemal complex (SC) that provides a transient but tight connection between homologous chromosomes. Here, we showed that DESYNAPTIC2 (DSY2), a coiled-coil protein, mediates DSB formation and is directly involved in SC assembly in maize (Zea mays). The dsy2 mutant exhibits homologous pairing defects, leading to sterility. Analyses revealed that DSB formation and the number of RADIATION SENSITIVE51 (RAD51) foci are largely reduced, and synapsis is completely abolished in dsy2 meiocytes. Super-resolution structured illumination microscopy showed that DSY2 is located on the AE and forms a distinct alternating pattern with the HORMA-domain protein ASYNAPTIC1 (ASY1). In the dsy2 mutant, localization of ASY1 is affected, and loading of the central element ZIPPER1 (ZYP1) is disrupted. Yeast two-hybrid and bimolecular fluorescence complementation experiments further demonstrated that ZYP1 interacts with DSY2 but does not interact with ASY1. Therefore, DSY2, an AE protein, not only mediates DSB formation but also bridges the AE and central element of SC during meiosis.
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Affiliation(s)
- Ding Hua Lee
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan National Chung-Hsing University, Taichung 40227, Taiwan Graduate Institute of Biotechnology, National Chung-Hsing University, Taichung 40227, Taiwan
| | - Yu-Hsin Kao
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Jia-Chi Ku
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Chien-Yu Lin
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Robert Meeley
- Crop Genetics Research, Pioneer Hi-Bred-A DuPont Business, Johnston, Iowa 50131
| | - Ya-Shiun Jan
- Potzu Branch Station, Tainan District Agricultural Research and Extension Station, Chiayi 61359, Taiwan
| | - Chung-Ju Rachel Wang
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan National Chung-Hsing University, Taichung 40227, Taiwan Biotechnology Center, National Chung-Hsing University, Taichung 40227, Taiwan
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6
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Cabral G, Marques A, Schubert V, Pedrosa-Harand A, Schlögelhofer P. Chiasmatic and achiasmatic inverted meiosis of plants with holocentric chromosomes. Nat Commun 2014; 5:5070. [PMID: 25295686 PMCID: PMC4190664 DOI: 10.1038/ncomms6070] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 08/25/2014] [Indexed: 11/09/2022] Open
Abstract
Meiosis is a specialized cell division in sexually reproducing organisms before gamete formation. Following DNA replication, the canonical sequence in species with monocentric chromosomes is characterized by reductional segregation of homologous chromosomes during the first and equational segregation of sister chromatids during the second meiotic division. Species with holocentric chromosomes employ specific adaptations to ensure regular disjunction during meiosis. Here we present the analysis of two closely related plant species with holocentric chromosomes that display an inversion of the canonical meiotic sequence, with the equational division preceding the reductional. In-depth analysis of the meiotic divisions of Rhynchospora pubera and R. tenuis reveals that during meiosis I sister chromatids are bi-oriented, display amphitelic attachment to the spindle and are subsequently separated. During prophase II, chromatids are connected by thin chromatin threads that appear instrumental for the regular disjunction of homologous non-sister chromatids in meiosis II. The absence of a defined centromere in organisms with holocentric chromosomes presents particular problems for the control of chromosome segregation during meiosis. Cabral et al. present evidence that two plant species overcome this challenge by inverting the conventional sequence of meiotic divisions.
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Affiliation(s)
- Gabriela Cabral
- 1] Department of Botany, Laboratory of Plant Cytogenetics and Evolution, Federal University of Pernambuco, Rua Nelson Chaves s/n, Recife, Pernambuco 50670-420, Brazil [2] Department of Chromosome Biology, Max F. Perutz Laboratories, University of Vienna, Dr Bohr-Gasse 9, Vienna A-1030, Austria
| | - André Marques
- Department of Botany, Laboratory of Plant Cytogenetics and Evolution, Federal University of Pernambuco, Rua Nelson Chaves s/n, Recife, Pernambuco 50670-420, Brazil
| | - Veit Schubert
- Leibniz Institute of Plant Genetics and Crop Plant Research, Corrensstraße 3, Gatersleben 06466, Germany
| | - Andrea Pedrosa-Harand
- Department of Botany, Laboratory of Plant Cytogenetics and Evolution, Federal University of Pernambuco, Rua Nelson Chaves s/n, Recife, Pernambuco 50670-420, Brazil
| | - Peter Schlögelhofer
- Department of Chromosome Biology, Max F. Perutz Laboratories, University of Vienna, Dr Bohr-Gasse 9, Vienna A-1030, Austria
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7
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Collaboration within the M1 aminopeptidase family promotes reproductive success in Caenorhabditis elegans. Dev Genes Evol 2014; 224:137-46. [DOI: 10.1007/s00427-014-0470-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Accepted: 03/06/2014] [Indexed: 11/24/2022]
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8
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Otto SP. Selective maintenance of recombination between the sex chromosomes. J Evol Biol 2014; 27:1431-42. [DOI: 10.1111/jeb.12324] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 12/11/2013] [Accepted: 12/20/2013] [Indexed: 02/05/2023]
Affiliation(s)
- S. P. Otto
- Department of Zoology & Biodiversity Research Centre; University of British Columbia; Vancouver BC Canada
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9
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De Storme N, Zamariola L, Mau M, Sharbel TF, Geelen D. Volume-based pollen size analysis: an advanced method to assess somatic and gametophytic ploidy in flowering plants. PLANT REPRODUCTION 2013; 26:65-81. [PMID: 23686220 DOI: 10.1007/s00497-012-0209-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Accepted: 12/31/2012] [Indexed: 05/12/2023]
Abstract
Pollen size is often used as a biological parameter to estimate the ploidy and viability of mature pollen grains. In general, pollen size quantification is performed one- or two-dimensionally using image-based diameter measurements. As these approaches are elaborate and time consuming, alternative approaches that enable a quick, reliable analysis of pollen size are highly relevant for plant research. In this study, we present the volume-based particle size analysis technique as an alternative method to characterize mature pollen. Based on a comparative assay using different plant species (including tomato, oilseed rape, kiwifruit, clover, among others), we found that volume-based pollen size measurements are not biased by the pollen shape or position and substantially reduce non-biological variation, allowing a more accurate determination of the actual pollen size. As such, volume-based particle size techniques have a strong discriminative power in detecting pollen size differences caused by alterations in the gametophytic ploidy level and therefore allow for a quick and reliable estimation of the somatic ploidy level. Based on observations in Arabidopsis thaliana gametophytic mutants and differentially reproducing Boechera polyantha lines, we additionally found that volume-based pollen size analysis provides quantitative and qualitative data about alterations in male sporogenesis, including aneuploid and diploid gamete formation. Volume-based pollen size analysis therefore not only provides a quick and easy methodology to determine the somatic ploidy level of flowering plants, but can also be used to determine the mode of reproduction and to quantify the level of diplogamete formation.
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Affiliation(s)
- Nico De Storme
- Department of Plant Production, Faculty of Bioscience Engineering, University of Ghent, Coupure Links 653, 9000, Ghent, Belgium
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10
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Pradillo M, López E, Linacero R, Romero C, Cuñado N, Sánchez-Morán E, Santos JL. Together yes, but not coupled: new insights into the roles of RAD51 and DMC1 in plant meiotic recombination. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2012; 69:921-33. [PMID: 22066484 DOI: 10.1111/j.1365-313x.2011.04845.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The eukaryotic recombinases RAD51 and DMC1 are essential for DNA strand-exchange between homologous chromosomes during meiosis. RAD51 is also expressed during mitosis, and mediates homologous recombination (HR) between sister chromatids. It has been suggested that DMC1 might be involved in the switch from intersister chromatid recombination in somatic cells to interhomolog meiotic recombination. At meiosis, the Arabidopsis Atrad51 null mutant fails to synapse and has extensive chromosome fragmentation. The Atdmc1 null mutant is also asynaptic, but in this case chromosome fragmentation is absent. Thus in plants, AtDMC1 appears to be indispensable for interhomolog homologous recombination, whereas AtRAD51 seems to be more involved in intersister recombination. In this work, we have studied a new AtRAD51 knock-down mutant, Atrad51-2, which expresses only a small quantity of RAD51 protein. Atrad51-2 mutant plants are sterile and hypersensitive to DNA double-strand break induction, but their vegetative development is apparently normal. The meiotic phenotype of the mutant consists of partial synapsis, an elevated frequency of univalents, a low incidence of chromosome fragmentation and multivalent chromosome associations. Surprisingly, non-homologous chromosomes are involved in 51% of bivalents. The depletion of AtDMC1 in the Atrad51-2 background results in the loss of bivalents and in an increase of chromosome fragmentation. Our results suggest that a critical level of AtRAD51 is required to ensure the fidelity of HR during interchromosomal exchanges. Assuming the existence of asymmetrical DNA strand invasion during the initial steps of recombination, we have developed a working model in which the initial step of strand invasion is mediated by AtDMC1, with AtRAD51 required to check the fidelity of this process.
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MESH Headings
- Arabidopsis/drug effects
- Arabidopsis/genetics
- Arabidopsis/metabolism
- Arabidopsis/radiation effects
- Arabidopsis Proteins/genetics
- Arabidopsis Proteins/metabolism
- Cell Cycle Proteins/genetics
- Cell Cycle Proteins/metabolism
- Chromosomes, Plant/genetics
- Chromosomes, Plant/metabolism
- Cisplatin/pharmacology
- DNA Breaks, Double-Stranded/radiation effects
- DNA, Plant/genetics
- DNA, Plant/metabolism
- Gamma Rays
- Gene Knockout Techniques
- Genetic Complementation Test
- Homologous Recombination
- Meiosis
- Metaphase
- Models, Genetic
- Phenotype
- Plants, Genetically Modified/drug effects
- Plants, Genetically Modified/genetics
- Plants, Genetically Modified/metabolism
- Plants, Genetically Modified/radiation effects
- Rad51 Recombinase/genetics
- Rad51 Recombinase/metabolism
- Rec A Recombinases/genetics
- Rec A Recombinases/metabolism
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Affiliation(s)
- Mónica Pradillo
- Departamento de Genética, Facultad de Biología, Universidad Complutense de Madrid, Madrid 28040, Spain.
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11
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Ferdous M, Higgins JD, Osman K, Lambing C, Roitinger E, Mechtler K, Armstrong SJ, Perry R, Pradillo M, Cuñado N, Franklin FCH. Inter-homolog crossing-over and synapsis in Arabidopsis meiosis are dependent on the chromosome axis protein AtASY3. PLoS Genet 2012; 8:e1002507. [PMID: 22319460 PMCID: PMC3271061 DOI: 10.1371/journal.pgen.1002507] [Citation(s) in RCA: 138] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Accepted: 12/11/2011] [Indexed: 12/13/2022] Open
Abstract
In this study we have analysed AtASY3, a coiled-coil domain protein that is required for normal meiosis in Arabidopsis. Analysis of an Atasy3-1 mutant reveals that loss of the protein compromises chromosome axis formation and results in reduced numbers of meiotic crossovers (COs). Although the frequency of DNA double-strand breaks (DSBs) appears moderately reduced in Atasy3-1, the main recombination defect is a reduction in the formation of COs. Immunolocalization studies in wild-type meiocytes indicate that the HORMA protein AtASY1, which is related to Hop1 in budding yeast, forms hyper-abundant domains along the chromosomes that are spatially associated with DSBs and early recombination pathway proteins. Loss of AtASY3 disrupts the axial organization of AtASY1. Furthermore we show that the AtASY3 and AtASY1 homologs BoASY3 and BoASY1, from the closely related species Brassica oleracea, are co-immunoprecipitated from meiocyte extracts and that AtASY3 interacts with AtASY1 via residues in its predicted coiled-coil domain. Together our results suggest that AtASY3 is a functional homolog of Red1. Since studies in budding yeast indicate that Red1 and Hop1 play a key role in establishing a bias to favor inter-homolog recombination (IHR), we propose that AtASY3 and AtASY1 may have a similar role in Arabidopsis. Loss of AtASY3 also disrupts synaptonemal complex (SC) formation. In Atasy3-1 the transverse filament protein AtZYP1 forms small patches rather than a continuous SC. The few AtMLH1 foci that remain in Atasy3-1 are found in association with the AtZYP1 patches. This is sufficient to prevent the ectopic recombination observed in the absence of AtZYP1, thus emphasizing that in addition to its structural role the protein is important for CO formation. Homologous recombination (HR) during prophase I of meiosis leads to the formation of physical connections, known as chiasmata, between homologous chromosomes (homologs). Chiasmata are essential for accurate homolog segregation at the first meiotic division. HR is initiated by the formation of DNA double-strand breaks (DSBs). As DNA replication prior to meiosis results in the duplication of each homolog to form two identical sister chromatids, a DSB in one sister chromatid could potentially be repaired using the other as the repair template rather than one of the two non-sister chromatids of the homolog. If this route were predominant, the formation of chiasmata would be disfavored and chromosome segregation would be compromised. However, during meiosis there is a strong bias towards inter-homolog recombination (IHR). In this study we have identified AtASY3, a component of the proteinaceous axes that organize the chromosomes during meiosis in Arabidopsis. We find that AtASY3 interacts with AtASY1, a previously identified axis protein that is essential for crossover formation. We show that loss of AtASY3 disrupts the axis-organization of AtASY1. This results in a substantial reduction in chiasmata, and there is extensive chromosome mis-segregation. We propose that loss of AtASY3 affects the efficiency of the inter-homolog bias.
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Affiliation(s)
- Maheen Ferdous
- School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - James D. Higgins
- School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Kim Osman
- School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Christophe Lambing
- School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | | | - Karl Mechtler
- Institute of Molecular Pathology (IMP), Vienna, Austria
- Institute of Molecular Biotechnology (IMBA), Vienna, Austria
| | - Susan J. Armstrong
- School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Ruth Perry
- School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Mónica Pradillo
- Departamento de Génetica, Facultad de Biología, Universidad Complutense de Madrid, Madrid, Spain
| | - Nieves Cuñado
- Departamento de Génetica, Facultad de Biología, Universidad Complutense de Madrid, Madrid, Spain
| | - F. Chris H. Franklin
- School of Biosciences, University of Birmingham, Birmingham, United Kingdom
- * E-mail:
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12
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Peer WA. The role of multifunctional M1 metallopeptidases in cell cycle progression. ANNALS OF BOTANY 2011; 107:1171-81. [PMID: 21258033 PMCID: PMC3091800 DOI: 10.1093/aob/mcq265] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
BACKGROUND Metallopeptidases of the M1 family are found in all phyla (except viruses) and are important in the cell cycle and normal growth and development. M1s often have spatiotemporal expression patterns which allow for strict regulation of activity. Mutations in the genes encoding M1s result in disease and are often lethal. This family of zinc metallopeptidases all share the catalytic region containing a signature amino acid exopeptidase (GXMXN) and a zinc binding (HEXXH[18X]E) motif. In addition, M1 aminopeptidases often also contain additional membrane association and/or protein interaction motifs. These protein interaction domains may function independently of M1 enzymatic activity and can contribute to multifunctionality of the proteins. SCOPE A brief review of M1 metalloproteases in plants and animals and their roles in the cell cycle is presented. In animals, human puromycin-sensitive aminopeptidase (PSA) acts during mitosis and perhaps meiosis, while the insect homologue puromycin-sensitive aminopeptidase (PAM-1) is required for meiotic and mitotic exit; the remaining human M1 family members appear to play a direct or indirect role in mitosis/cell proliferation. In plants, meiotic prophase aminopeptidase 1 (MPA1) is essential for the first steps in meiosis, and aminopeptidase M1 (APM1) appears to be important in mitosis and cell division. CONCLUSIONS M1 metalloprotease activity in the cell cycle is conserved across phyla. The activities of the multifunctional M1s, processing small peptides and peptide hormones and contributing to protein trafficking and signal transduction processes, either directly or indirectly impact on the cell cycle. Identification of peptide substrates and interacting protein partners is required to understand M1 function in fertility and normal growth and development in plants.
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Affiliation(s)
- Wendy Ann Peer
- Department of Horticulture and Landscape Architecture, 625 Agriculture Mall Drive, Purdue University, West Lafayette, IN 47907 USA.
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13
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Hosein FN, Bandyopadhyay A, Peer WA, Murphy AS. The catalytic and protein-protein interaction domains are required for APM1 function. PLANT PHYSIOLOGY 2010; 152:2158-72. [PMID: 20154099 PMCID: PMC2850015 DOI: 10.1104/pp.109.148742] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Aminopeptidase M1 (APM1) is essential for embryonic, vegetative, and reproductive development in Arabidopsis (Arabidopsis thaliana). Here, we show that, like mammalian M1 proteases, APM1 appears to have distinct enzymatic and protein-protein interaction domains and functions as a homodimer. Arabidopsis seedlings treated with ezetimibe, an inhibitor of M1 protein-protein interactions, mimicked a subset of apm1 phenotypes distinct from those resulting from treatment with PAQ-22, an inhibitor of M1 catalytic activity, suggesting that the APM1 catalytic and interaction domains can function independently. apm1-1 knockdown mutants transformed with catalytically inactive APM1 did not prevent seedling lethality. However, apm1-2 has a functional enzymatic domain but lacks the carboxyl (C) terminus, and transformation with catalytically inactive APM1 rescued the mutant. Overexpression of human insulin-responsive aminopeptidase/oxytocinase rescued all apm1 phenotypes, suggesting that the catalytic activity was sufficient to compensate for loss of APM1 function, while overexpression of catalytically inactive insulin-responsive aminopeptidase/oxytocinase only rescued apm1-2. Increased catalytic activity alone is not sufficient to compensate for loss of APM1 function, as overexpression of another Arabidopsis M1 family member lacking an extended C terminus did not rescue apm1-1. The protein interactions facilitating enzymatic activity appear to be dependent on the C terminus of APM1, as transformation with an open reading frame containing an internal deletion of a portion of the C terminus or a point mutation in a dileucine motif did not rescue the mutant. These results suggest that both the catalytic and interaction domains are necessary for APM1 function but that APM1 function and dimerization do not require these domains to be present in the same linear molecule.
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Peer WA, Hosein FN, Bandyopadhyay A, Makam SN, Otegui MS, Lee GJ, Blakeslee JJ, Cheng Y, Titapiwatanakun B, Yakubov B, Bangari B, Murphy AS. Mutation of the membrane-associated M1 protease APM1 results in distinct embryonic and seedling developmental defects in Arabidopsis. THE PLANT CELL 2009; 21:1693-721. [PMID: 19531600 PMCID: PMC2714933 DOI: 10.1105/tpc.108.059634] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2008] [Revised: 05/14/2009] [Accepted: 06/01/2009] [Indexed: 05/20/2023]
Abstract
Aminopeptidase M1 (APM1), a single copy gene in Arabidopsis thaliana, encodes a metallopeptidase originally identified via its affinity for, and hydrolysis of, the auxin transport inhibitor 1-naphthylphthalamic acid (NPA). Mutations in this gene result in haploinsufficiency. Loss-of-function mutants show irregular, uncoordinated cell divisions throughout embryogenesis, affecting the shape and number of cotyledons and the hypophysis, and is seedling lethal at 5 d after germination due to root growth arrest. Quiescent center and cell cycle markers show no signals in apm1-1 knockdown mutants, and the ground tissue specifiers SHORTROOT and SCARECROW are misexpressed or mislocalized. apm1 mutants have multiple, fused cotyledons and hypocotyls with enlarged epidermal cells with cell adhesion defects. apm1 alleles show defects in gravitropism and auxin transport. Gravistimulation decreases APM1 expression in auxin-accumulating root epidermal cells, and auxin treatment increases expression in the stele. On sucrose gradients, APM1 occurs in unique light membrane fractions. APM1 localizes at the margins of Golgi cisternae, plasma membrane, select multivesicular bodies, tonoplast, dense intravacuolar bodies, and maturing metaxylem cells. APM1 associates with brefeldin A-sensitive endomembrane structures and the plasma membrane in cortical and epidermal cells. The auxin-related phenotypes and mislocalization of auxin efflux proteins in apm1 are consistent with biochemical interactions between APM1 and NPA.
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Affiliation(s)
- Wendy Ann Peer
- Department of Horticulture, Purdue University, West Lafayette, Indiana 47907, USA
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Abstract
Advances in molecular biology and in the genetics of Arabidopsis thaliana have led to this organism becoming an important model for the analysis of meiosis in plants. Cytogenetic investigations are pivotal to meiotic studies and a number of technological improvements for Arabidopsis cytology have provided a range of tools to investigate chromosome behaviour during meiosis. This chapter includes protocols on basic cytology, FISH analysis, immunocytology, a procedure for a meiotic time course and electron microscopy.
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Higgins JD, Vignard J, Mercier R, Pugh AG, Franklin FCH, Jones GH. AtMSH5 partners AtMSH4 in the class I meiotic crossover pathway in Arabidopsis thaliana, but is not required for synapsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2008; 55:28-39. [PMID: 18318687 DOI: 10.1111/j.1365-313x.2008.03470.x] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
MSH5, a meiosis-specific member of the MutS-homologue family of genes, is required for normal levels of recombination in budding yeast, mouse and Caenorhabditis elegans. In this paper we report the identification and characterization of the Arabidopsis homologue of MSH5 (AtMSH5). Transcripts of AtMSH5 are specific to reproductive tissues, and immunofluorescence studies indicate that expression of the protein is abundant during prophase I of meiosis. In a T-DNA tagged insertional mutant (Atmsh5-1), recombination is reduced to about 13% of wild-type levels. The residual chiasmata are randomly distributed between cells and chromosomes. These data provide further evidence for at least two pathways of meiotic recombination in Arabidopsis and indicate that AtMSH5 protein is required for the formation of class I interference-sensitive crossovers. Localization of AtMSH5 to meiotic chromosomes occurs at leptotene and is dependent on DNA double-strand break formation and strand exchange. Localization of AtMSH5 to the chromatin at mid-prophase I is dependent on expression of AtMSH4. At late zygotene/early pachytene a proportion of AtMSH5 foci co-localize with AtMLH1 which marks crossover-designated sites. Chromosome synapsis appears to proceed normally, without significant delay, in Atmsh5-1 but the pachytene stage is extended by several hours, indicative of the operation of a surveillance system that monitors the progression of prophase I.
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Affiliation(s)
- James D Higgins
- School of Biosciences, University of Birmingham, Birmingham B15 2TT, UK
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Smolikov S, Schild-Prüfert K, Colaiácovo MP. CRA-1 uncovers a double-strand break-dependent pathway promoting the assembly of central region proteins on chromosome axes during C. elegans meiosis. PLoS Genet 2008; 4:e1000088. [PMID: 18535664 PMCID: PMC2408554 DOI: 10.1371/journal.pgen.1000088] [Citation(s) in RCA: 45] [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: 12/18/2007] [Accepted: 05/02/2008] [Indexed: 11/18/2022] Open
Abstract
The synaptonemal complex (SC), a tripartite proteinaceous structure that forms between homologous chromosomes during meiosis, is crucial for faithful chromosome segregation. Here we identify CRA-1, a novel and conserved protein that is required for the assembly of the central region of the SC during C. elegans meiosis. In the absence of CRA-1, central region components fail to extensively localize onto chromosomes at early prophase and instead mostly surround the chromatin at this stage. Later in prophase, central region proteins polymerize along chromosome axes, but for the most part fail to connect the axes of paired homologous chromosomes. This defect results in an inability to stabilize homologous pairing interactions, altered double-strand break (DSB) repair progression, and a lack of chiasmata. Surprisingly, DSB formation and repair are required to promote the polymerization of the central region components along meiotic chromosome axes in cra-1 mutants. In the absence of both CRA-1 and any one of the C. elegans homologs of SPO11, MRE11, RAD51, or MSH5, the polymerization observed along chromosome axes is perturbed, resulting in the formation of aggregates of the SC central region proteins. While radiation-induced DSBs rescue this polymerization in cra-1; spo-11 mutants, they fail to do so in cra-1; mre-11, cra-1; rad-51, and cra-1; msh-5 mutants. Taken together, our studies place CRA-1 as a key component in promoting the assembly of a tripartite SC structure. Moreover, they reveal a scenario in which DSB formation and repair can drive the polymerization of SC components along chromosome axes in C. elegans. Accurate meiotic chromosome segregation relies on homologous chromosome pairing, synapsis, and recombination. Although formation of the “zipper-like” structure known as the synaptonemal complex (SC) is critical for homologous chromosome synapsis in most sexually reproducing organisms, regulation of SC formation is still poorly understood. Previous studies revealed that whereas SC formation is dependent on the formation of double-strand breaks (DSBs) in yeast, plants, and mammals, it is DSB-independent in flies and nematodes. Here we introduce CRA-1, a novel and conserved protein required for the formation of the SC in the nematode C. elegans. In cra-1 mutants, SC central region components for the most part fail to link homologous chromosome axes and stabilize homologous pairing interactions. As a result, crossover recombination is impaired and there is increased chromosome nondisjunction. Analysis of cra-1 mutants also reveals that DSB formation and repair can promote the assembly of SC proteins along chromosome axes. Therefore, we propose that CRA-1 promotes a productive SC assembly, and demonstrate, in our analysis of cra-1 mutants, an unanticipated interconnection between the recruitment of central region components onto chromosome axes and the recombination pathway in C. elegans.
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Affiliation(s)
- Sarit Smolikov
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Kristina Schild-Prüfert
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Mónica P. Colaiácovo
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
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Sanchez-Moran E, Osman K, Higgins J, Pradillo M, Cuñado N, Jones G, Franklin F. ASY1 coordinates early events in the plant meiotic recombination pathway. Cytogenet Genome Res 2008; 120:302-12. [DOI: 10.1159/000121079] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/26/2007] [Indexed: 11/19/2022] Open
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19
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Siroky J. Chromosome landmarks as tools to study the genome of Arabidopsis thaliana. Cytogenet Genome Res 2008; 120:202-9. [DOI: 10.1159/000121068] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/17/2007] [Indexed: 12/17/2022] Open
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Sanchez-Moran E, Santos JL, Jones GH, Franklin FCH. ASY1 mediates AtDMC1-dependent interhomolog recombination during meiosis in Arabidopsis. Genes Dev 2007; 21:2220-33. [PMID: 17785529 PMCID: PMC1950860 DOI: 10.1101/gad.439007] [Citation(s) in RCA: 205] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
ASY1 is an Arabidopsis protein required for synapsis and crossover formation during meiosis. The chronology of meiotic recombination has been investigated in wild type and an asy1 mutant. We observe a delay between the appearance of chromatin-associated AtSPO11-1 foci and DNA double-strand break (DSB) formation, which occurs contemporaneously with chromosome axis formation and transition of ASY1 from chromatin-associated foci to a linear axis-associated signal. DSBs are formed independently of ASY1 in an AtSPO11-1-dependent manner. They are partially restored in Atspo11-1-3 using cisplatin, but their control appears abnormal. Axis morphogenesis is independent of ASY1, but axis structure may be compromised in asy1. Localization of the strand exchange proteins AtRAD51 and AtDMC1 to the chromatin occurs asynchronously shortly after DSB formation, with AtDMC1 localizing in advance of AtRAD51. In wild-type nuclei, both recombinases form numerous foci that persist for approximately 12 h before gradually decreasing in number. In asy1, initial localization of AtDMC1 is normal, but declines abruptly such that interhomolog recombination is severely compromised. Limited ASY1-independent, DMC1-dependent interhomolog recombination remains, but appears restricted to subtelomeric sequences where the homologs are fortuitously in proximity. Thus, ASY1 plays a key role in coordinating the activity of the RecA homologs to create a bias in favor of interhomolog recombination.
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Affiliation(s)
| | - Juan-Luis Santos
- Departamento de Genetica, Universidad Complutense de Madrid 28040, Spain
| | - Gareth H. Jones
- School of Biosciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - F. Christopher H. Franklin
- School of Biosciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
- Corresponding author.E-MAIL ; FAX 44-121-4145925
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Hartung F, Wurz-Wildersinn R, Fuchs J, Schubert I, Suer S, Puchta H. The catalytically active tyrosine residues of both SPO11-1 and SPO11-2 are required for meiotic double-strand break induction in Arabidopsis. THE PLANT CELL 2007; 19:3090-9. [PMID: 17965269 PMCID: PMC2174718 DOI: 10.1105/tpc.107.054817] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2007] [Revised: 10/10/2007] [Accepted: 10/15/2007] [Indexed: 05/18/2023]
Abstract
SPO11, a homolog of the subunit A of the archaebacterial topoisomerase VI, is essential for double-strand break (DSB)-induced initiation of meiotic recombination. In contrast with single homologs in animals and yeasts, three homologs are present in Arabidopsis thaliana and other higher plants. Whereas At SPO11-3 is involved in somatic endoreduplication, At SPO11-1 and, as recently shown, At SPO11-2 are essential for the initiation of meiotic recombination. Further defining the role of At SPO11-2, we were able to demonstrate that it is required for proper chromosome segregation, as its loss resulted in aneuploidy in the surviving progeny. The double mutant spo11-1 spo11-2 does not differ phenotypically from the single mutants, indicating that both proteins are required for the same step. Contrary to the observations for the At rad51-1 single mutant, the combination of spo11-2 and rad51-1 did not lead to chromosome fragmentation, indicating that SPO11-2, like SPO11-1, is required for DSB induction. As the meiotic phenotype of both single SPO11 mutants can be reversed by complementation using the full-length genes but not the same constructs mutated in their respective catalytically active Tyr, both proteins seem to participate directly in the DNA breakage reaction. The active involvement of two SPO11 homologs for DSB formation reveals a striking difference between plants and other eukaryotes in meiosis.
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Affiliation(s)
- Frank Hartung
- Botanisches Institut II, Universität Karlsruhe, 76128 Karlsruhe, Germany
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