1
|
Nguyen TH, Kang BY, Kim HH. Chromosomal dynamics in Senna: comparative PLOP-FISH analysis of tandem repeats and flow cytometric nuclear genome size estimations. FRONTIERS IN PLANT SCIENCE 2023; 14:1288220. [PMID: 38173930 PMCID: PMC10762312 DOI: 10.3389/fpls.2023.1288220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 11/08/2023] [Indexed: 01/05/2024]
Abstract
Introduction Tandem repeats (TRs) occur abundantly in plant genomes. They play essential roles that affect genome organization and evolution by inducing or generating chromosomal rearrangements such as duplications, deletions, inversions, and translocations. These impact gene expression and chromosome structure and even contribute to the emergence of new species. Method We investigated the effects of TRs on speciation in Senna genus by performing a comparative analysis using fluorescence in situ hybridization (FISH) with S. tora-specific TR probes. We examined the chromosomal distribution of these TRs and compared the genome sizes of seven Senna species (estimated using flow cytometry) to better understand their evolutionary relationships. Results Two (StoTR03_159 and StoTR04_55) of the nine studied TRs were not detected in any of the seven Senna species, whereas the remaining seven were found in all or some species with patterns that were similar to or contrasted with those of S. tora. Of these studies species, only S. angulata showed significant genome rearrangements and dysploid karyotypes resembling those of S. tora. The genome sizes varied among these species and did not positively correlate with chromosome number. Notably, S. angulata had the fewest chromosomes (2n = 22) but a relatively large genome size. Discussion These findings reveal the dynamics of TRs and provide a cytogenetic depiction of chromosomal rearrangements during speciation in Senna. To further elucidate the dynamics of repeat sequences in Senna, future studies must include related species and extensive repeatomic studies, including those on transposable elements.
Collapse
Affiliation(s)
| | | | - Hyun Hee Kim
- Chromosome Research Institute, Department of Chemistry & Life Science, Sahmyook University, Seoul, Republic of Korea
| |
Collapse
|
2
|
Dalíková M, Provazníková I, Provazník J, Grof-Tisza P, Pepi A, Nguyen P. The Role of Repetitive Sequences in Repatterning of Major Ribosomal DNA Clusters in Lepidoptera. Genome Biol Evol 2023; 15:evad090. [PMID: 37226278 PMCID: PMC10257491 DOI: 10.1093/gbe/evad090] [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: 05/31/2022] [Revised: 04/27/2023] [Accepted: 05/09/2023] [Indexed: 05/26/2023] Open
Abstract
Genes for major ribosomal RNAs (rDNA) are present in multiple copies mainly organized in tandem arrays. The number and position of rDNA loci can change dynamically and their repatterning is presumably driven by other repetitive sequences. We explored a peculiar rDNA organization in several representatives of Lepidoptera with either extremely large or numerous rDNA clusters. We combined molecular cytogenetics with analyses of second- and third-generation sequencing data to show that rDNA spreads as a transcription unit and reveal association between rDNA and various repeats. Furthermore, we performed comparative long read analyses among the species with derived rDNA distribution and moths with a single rDNA locus, which is considered ancestral. Our results suggest that satellite arrays, rather than mobile elements, facilitate homology-mediated spread of rDNA via either integration of extrachromosomal rDNA circles or ectopic recombination. The latter arguably better explains preferential spread of rDNA into terminal regions of lepidopteran chromosomes as efficiency of ectopic recombination depends on the proximity of homologous sequences to telomeres.
Collapse
Affiliation(s)
- Martina Dalíková
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
- Institute of Entomology, Biology Centre CAS, České Budějovice, Czech Republic
| | - Irena Provazníková
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
- Institute of Entomology, Biology Centre CAS, České Budějovice, Czech Republic
- European Molecular Biology Laboratory, Heidelberg, Germany
| | - Jan Provazník
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
- European Molecular Biology Laboratory, Heidelberg, Germany
| | - Patrick Grof-Tisza
- Institute of Biology, Laboratory of Evolutionary Entomology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Adam Pepi
- Department of Biology, Tufts University
| | - Petr Nguyen
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
- Institute of Entomology, Biology Centre CAS, České Budějovice, Czech Republic
| |
Collapse
|
3
|
Hua YP, Wu PJ, Zhang TY, Song HL, Zhang YF, Chen JF, Yue CP, Huang JY, Sun T, Zhou T. Genome-Scale Investigation of GARP Family Genes Reveals Their Pivotal Roles in Nutrient Stress Resistance in Allotetraploid Rapeseed. Int J Mol Sci 2022; 23:ijms232214484. [PMID: 36430962 PMCID: PMC9698747 DOI: 10.3390/ijms232214484] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 11/14/2022] [Accepted: 11/18/2022] [Indexed: 11/23/2022] Open
Abstract
The GARP genes are plant-specific transcription factors (TFs) and play key roles in regulating plant development and abiotic stress resistance. However, few systematic analyses of GARPs have been reported in allotetraploid rapeseed (Brassica napus L.) yet. In the present study, a total of 146 BnaGARP members were identified from the rapeseed genome based on the sequence signature. The BnaGARP TFs were divided into five subfamilies: ARR, GLK, NIGT1/HRS1/HHO, KAN, and PHL subfamilies, and the members within the same subfamilies shared similar exon-intron structures and conserved motif configuration. Analyses of the Ka/Ks ratios indicated that the GARP family principally underwent purifying selection. Several cis-acting regulatory elements, essential for plant growth and diverse biotic and abiotic stresses, were identified in the promoter regions of BnaGARPs. Further, 29 putative miRNAs were identified to be targeting BnaGARPs. Differential expression of BnaGARPs under low nitrate, ammonium toxicity, limited phosphate, deficient boron, salt stress, and cadmium toxicity conditions indicated their potential involvement in diverse nutrient stress responses. Notably, BnaA9.HHO1 and BnaA1.HHO5 were simultaneously transcriptionally responsive to these nutrient stresses in both hoots and roots, which indicated that BnaA9.HHO1 and BnaA1.HHO5 might play a core role in regulating rapeseed resistance to nutrient stresses. Therefore, this study would enrich our understanding of molecular characteristics of the rapeseed GARPs and will provide valuable candidate genes for further in-depth study of the GARP-mediated nutrient stress resistance in rapeseed.
Collapse
Affiliation(s)
- Ying-Peng Hua
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Peng-Jia Wu
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Tian-Yu Zhang
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Hai-Li Song
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Yi-Fan Zhang
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Jun-Fan Chen
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Cai-Peng Yue
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Jin-Yong Huang
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Tao Sun
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
- Correspondence: (T.S.); (T.Z.); Tel.: +86-187-0271-0749 (T.Z.)
| | - Ting Zhou
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
- Correspondence: (T.S.); (T.Z.); Tel.: +86-187-0271-0749 (T.Z.)
| |
Collapse
|
4
|
Mengozzi A, Pugliese NR, Taddei S, Masi S, Virdis A. Microvascular Inflammation and Cardiovascular Prevention: The Role of Microcirculation as Earlier Determinant of Cardiovascular Risk. High Blood Press Cardiovasc Prev 2021; 29:41-48. [PMID: 34855153 DOI: 10.1007/s40292-021-00493-3] [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: 11/13/2021] [Accepted: 11/20/2021] [Indexed: 12/18/2022] Open
Abstract
Healthcare systems encumbered by cardiovascular diseases demand adequate cardiovascular prevention. Indeed, even with the most novel therapies, the residual cardiovascular risk still fuels morbidity and mortality. Addressing inflammation as a putative mediator of this risk has brought along promising in vitro results, though large clinical trials have only in part confirmed them. To fully exploit the therapeutic potential between the inflammatory hypothesis, a change of viewpoint is required. Focus on microcirculation, whose dysfunction is the primary driver of cardiometabolic disease, is mandatory. Several factors play a pivotal role in the capacity of microvascular inflammation to promote a health-to-disease transition: the adipose tissue (in particular, perivascular and epicardial), the mitochondria function, the hyperglycemic damage and their epigenetic signature. Indeed, the low-grade inflammatory response, which is now an acknowledged hallmark of cardiometabolic disease, is promoted by these mediators and leaves a permanent epigenetic scar on the microvasculature. Even if a more profound knowledge about the mechanisms of metabolic memory has been brought to light by recent evidence, we still have to fully understand its mechanisms and clinical potential. Addressing the detrimental role of inflammation by targeting the microvascular phenotype and leveraging epigenetics is the road down which we must go to achieve satisfactory cardiovascular prevention, ultimately leading to disease-free ageing.
Collapse
Affiliation(s)
- Alessandro Mengozzi
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.,Institute of Life Sciences, Sant'Anna School of Advanced Studies, Pisa, Italy
| | | | - Stefano Taddei
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Stefano Masi
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.,Institute of Cardiovascular Science, University College London, London, UK
| | - Agostino Virdis
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
| |
Collapse
|
5
|
Subgenome Discrimination in Brassica and Raphanus Allopolyploids Using Microsatellites. Cells 2021; 10:cells10092358. [PMID: 34572008 PMCID: PMC8466703 DOI: 10.3390/cells10092358] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 09/01/2021] [Accepted: 09/03/2021] [Indexed: 01/11/2023] Open
Abstract
Intergeneric crosses between Brassica species and Raphanus sativus have produced crops with prominent shoot and root systems of Brassica and R. sativus, respectively. It is necessary to discriminate donor genomes when studying cytogenetic stability in distant crosses to identify homologous chromosome pairing, and microsatellite repeats have been used to discriminate subgenomes in allopolyploids. To identify genome-specific microsatellites, we explored the microsatellite content in three Brassica species (B. rapa, AA, B. oleracea, CC, and B. nigra, BB) and R. sativus (RR) genomes, and validated their genome specificity by fluorescence in situ hybridization. We identified three microsatellites showing A, C, and B/R genome specificity. ACBR_msat14 and ACBR_msat20 were detected in the A and C chromosomes, respectively, and ACBR_msat01 was detected in B and R genomes. However, we did not find a microsatellite that discriminated the B and R genomes. The localization of ACBR_msat20 in the 45S rDNA array in ×Brassicoraphanus 977 corroborated the association of the 45S rDNA array with genome rearrangement. Along with the rDNA and telomeric repeat probes, these microsatellites enabled the easy identification of homologous chromosomes. These data demonstrate the utility of microsatellites as probes in identifying subgenomes within closely related Brassica and Raphanus species for the analysis of genetic stability of new synthetic polyploids of these genomes.
Collapse
|
6
|
Park SG, Noh E, Choi S, Choi B, Shin IG, Yoo SI, Lee DJ, Ji S, Kim HS, Hwang YJ, Kim JS, Batley J, Lim YP, Edwards D, Hong CP. Draft Genome Assembly and Transcriptome Dataset for European Turnip ( Brassica rapa L. ssp. rapifera), ECD4 Carrying Clubroot Resistance. Front Genet 2021; 12:651298. [PMID: 34276765 PMCID: PMC8285094 DOI: 10.3389/fgene.2021.651298] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Accepted: 06/01/2021] [Indexed: 12/15/2022] Open
Affiliation(s)
| | - Eonji Noh
- Theragen Bio Co., Ltd., Suwon, South Korea
| | - SuRyun Choi
- Department of Horticulture, College of Agriculture and Life Science, Chungnam National University, Daejeon, South Korea
| | - Boram Choi
- Theragen Bio Co., Ltd., Suwon, South Korea
| | | | | | | | - Sumin Ji
- Theragen Bio Co., Ltd., Suwon, South Korea
| | | | - Yoon-Jung Hwang
- Department of Chemistry Life Science, Sahmyook University, Seoul, South Korea
| | - Jung Sun Kim
- Genomics Division, National Institute of Agricultural Sciences, Rural Development Administration, Jeonju, South Korea
| | - Jacqueline Batley
- School of Biological Sciences and Institute of Agriculture, University of Western Australia, Perth, WA, Australia
| | - Yong Pyo Lim
- Department of Horticulture, College of Agriculture and Life Science, Chungnam National University, Daejeon, South Korea
| | - David Edwards
- School of Biological Sciences and Institute of Agriculture, University of Western Australia, Perth, WA, Australia
| | | |
Collapse
|
7
|
Cuacos M, Lambing C, Pachon-Penalba M, Osman K, Armstrong SJ, Henderson IR, Sanchez-Moran E, Franklin FCH, Heckmann S. Meiotic chromosome axis remodelling is critical for meiotic recombination in Brassica rapa. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:3012-3027. [PMID: 33502451 PMCID: PMC8023211 DOI: 10.1093/jxb/erab035] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 01/21/2021] [Indexed: 05/23/2023]
Abstract
Meiosis generates genetic variation through homologous recombination (HR) that is harnessed during breeding. HR occurs in the context of meiotic chromosome axes and the synaptonemal complex. To study the role of axis remodelling in crossover (CO) formation in a crop species, we characterized mutants of the axis-associated protein ASY1 and the axis-remodelling protein PCH2 in Brassica rapa. asy1 plants form meiotic chromosome axes that fail to synapse. CO formation is almost abolished, and residual chiasmata are proportionally enriched in terminal chromosome regions, particularly in the nucleolar organizing region (NOR)-carrying chromosome arm. pch2 plants show impaired ASY1 loading and remodelling, consequently achieving only partial synapsis, which leads to reduced CO formation and loss of the obligatory CO. PCH2-independent chiasmata are proportionally enriched towards distal chromosome regions. Similarly, in Arabidopsis pch2, COs are increased towards telomeric regions at the expense of (peri-) centromeric COs compared with the wild type. Taken together, in B. rapa, axis formation and remodelling are critical for meiotic fidelity including synapsis and CO formation, and in asy1 and pch2 CO distributions are altered. While asy1 plants are sterile, pch2 plants are semi-sterile and thus PCH2 could be an interesting target for breeding programmes.
Collapse
Affiliation(s)
- Maria Cuacos
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) OT Gatersleben, D-06466 Seeland, Germany
| | - Christophe Lambing
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, UK
| | | | - Kim Osman
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Susan J Armstrong
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Ian R Henderson
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, UK
| | | | | | - Stefan Heckmann
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) OT Gatersleben, D-06466 Seeland, Germany
| |
Collapse
|
8
|
Ta TD, Waminal NE, Nguyen TH, Pellerin RJ, Kim HH. Comparative FISH analysis of Senna tora tandem repeats revealed insights into the chromosome dynamics in Senna. Genes Genomics 2021; 43:237-249. [PMID: 33655486 PMCID: PMC7966213 DOI: 10.1007/s13258-021-01051-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Accepted: 01/13/2021] [Indexed: 12/26/2022]
Abstract
BACKGROUND DNA tandem repeats (TRs) are often abundant and occupy discrete regions in eukaryotic genomes. These TRs often cause or generate chromosomal rearrangements, which, in turn, drive chromosome evolution and speciation. Tracing the chromosomal distribution of TRs could therefore provide insights into the chromosome dynamics and speciation among closely related taxa. The basic chromosome number in the genus Senna is 2n = 28, but dysploid species like Senna tora have also been observed. OBJECTIVE To understand the dynamics of these TRs and their impact on S. tora dysploidization. METHODS We performed a comparative fluorescence in situ hybridization (FISH) analysis among nine closely related Senna species and compared the chromosomal distribution of these repeats from a cytotaxonomic perspective by using the ITS1-5.8S-ITS2 sequence to infer phylogenetic relationships. RESULTS Of the nine S. tora TRs, two did not show any FISH signal whereas seven TRs showed similar and contrasting patterns to other Senna species. StoTR01_86, which was localized in the pericentromeric regions in all S. tora, but not at the nucleolar organizer region (NOR) site, was colocalized at the NOR site in all species except in S. siamea. StoTR02_7_tel was mostly localized at chromosome termini, but some species had an interstitial telomeric repeat in a few chromosomes. StoTR05_180 was distributed in the subtelomeric region in most species and was highly amplified in the pericentromeric region in some species. StoTR06_159 was either absent or colocalized in the NOR site in some species, and StoIGS_463, which was localized at the NOR site in S. tora, was either absent or localized at the subtelomeric or pericentromeric regions in other species. CONCLUSIONS These data suggest that TRs play important roles in S. tora dysploidy and suggest the involvement of 45S rDNA intergenic spacers in "carrying" repeats during genome reshuffling.
Collapse
Affiliation(s)
- Thanh Dat Ta
- Department of Chemistry and Life Science, Bioscience Institute, Sahmyook University, Seoul, 01795, Republic of Korea
| | - Nomar Espinosa Waminal
- Department of Chemistry and Life Science, Bioscience Institute, Sahmyook University, Seoul, 01795, Republic of Korea
| | - Thi Hong Nguyen
- Department of Chemistry and Life Science, Bioscience Institute, Sahmyook University, Seoul, 01795, Republic of Korea
| | - Remnyl Joyce Pellerin
- Department of Chemistry and Life Science, Bioscience Institute, Sahmyook University, Seoul, 01795, Republic of Korea
| | - Hyun Hee Kim
- Department of Chemistry and Life Science, Bioscience Institute, Sahmyook University, Seoul, 01795, Republic of Korea.
| |
Collapse
|
9
|
Waminal NE, Pellerin RJ, Kang SH, Kim HH. Chromosomal Mapping of Tandem Repeats Revealed Massive Chromosomal Rearrangements and Insights Into Senna tora Dysploidy. FRONTIERS IN PLANT SCIENCE 2021; 12:629898. [PMID: 33643358 PMCID: PMC7902697 DOI: 10.3389/fpls.2021.629898] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 01/21/2021] [Indexed: 05/16/2023]
Abstract
Tandem repeats can occupy a large portion of plant genomes and can either cause or result from chromosomal rearrangements, which are important drivers of dysploidy-mediated karyotype evolution and speciation. To understand the contribution of tandem repeats in shaping the extant Senna tora dysploid karyotype, we analyzed the composition and abundance of tandem repeats in the S. tora genome and compared the chromosomal distribution of these repeats between S. tora and a closely related euploid, Senna occidentalis. Using a read clustering algorithm, we identified the major S. tora tandem repeats and visualized their chromosomal distribution by fluorescence in situ hybridization. We identified eight independent repeats covering ~85 Mb or ~12% of the S. tora genome. The unit lengths and copy numbers had ranges of 7-5,833 bp and 325-2.89 × 106, respectively. Three short duplicated sequences were found in the 45S rDNA intergenic spacer, one of which was also detected at an extra-NOR locus. The canonical plant telomeric repeat (TTTAGGG)n was also detected as very intense signals in numerous pericentromeric and interstitial loci. StoTR05_180, which showed subtelomeric distribution in Senna occidentalis, was predominantly pericentromeric in S. tora. The unusual chromosomal distribution of tandem repeats in S. tora not only enabled easy identification of individual chromosomes but also revealed the massive chromosomal rearrangements that have likely played important roles in shaping its dysploid karyotype.
Collapse
Affiliation(s)
- Nomar Espinosa Waminal
- Department of Chemistry and Life Science, BioScience Institute, Sahmyook University, Seoul, South Korea
| | - Remnyl Joyce Pellerin
- Department of Chemistry and Life Science, BioScience Institute, Sahmyook University, Seoul, South Korea
| | - Sang-Ho Kang
- Genomics Division, National Institute of Agricultural Sciences, Rural Development Administration, Jeonju, South Korea
| | - Hyun Hee Kim
- Department of Chemistry and Life Science, BioScience Institute, Sahmyook University, Seoul, South Korea
- *Correspondence: Hyun Hee Kim
| |
Collapse
|
10
|
Rousseau-Gueutin M, Belser C, Da Silva C, Richard G, Istace B, Cruaud C, Falentin C, Boideau F, Boutte J, Delourme R, Deniot G, Engelen S, de Carvalho JF, Lemainque A, Maillet L, Morice J, Wincker P, Denoeud F, Chèvre AM, Aury JM. Long-read assembly of the Brassica napus reference genome Darmor-bzh. Gigascience 2020; 9:giaa137. [PMID: 33319912 PMCID: PMC7736779 DOI: 10.1093/gigascience/giaa137] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 09/18/2020] [Accepted: 11/09/2020] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND The combination of long reads and long-range information to produce genome assemblies is now accepted as a common standard. This strategy not only allows access to the gene catalogue of a given species but also reveals the architecture and organization of chromosomes, including complex regions such as telomeres and centromeres. The Brassica genus is not exempt, and many assemblies based on long reads are now available. The reference genome for Brassica napus, Darmor-bzh, which was published in 2014, was produced using short reads and its contiguity was extremely low compared with current assemblies of the Brassica genus. FINDINGS Herein, we report the new long-read assembly of Darmor-bzh genome (Brassica napus) generated by combining long-read sequencing data and optical and genetic maps. Using the PromethION device and 6 flowcells, we generated ∼16 million long reads representing 93× coverage and, more importantly, 6× with reads longer than 100 kb. This ultralong-read dataset allows us to generate one of the most contiguous and complete assemblies of a Brassica genome to date (contig N50 > 10 Mb). In addition, we exploited all the advantages of the nanopore technology to detect modified bases and sequence transcriptomic data using direct RNA to annotate the genome and focus on resistance genes. CONCLUSION Using these cutting-edge technologies, and in particular by relying on all the advantages of the nanopore technology, we provide the most contiguous Brassica napus assembly, a resource that will be valuable to the Brassica community for crop improvement and will facilitate the rapid selection of agronomically important traits.
Collapse
Affiliation(s)
| | - Caroline Belser
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 2 rue Gaston Crémieux, 91057 Evry, France
| | - Corinne Da Silva
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 2 rue Gaston Crémieux, 91057 Evry, France
| | - Gautier Richard
- IGEPP, INRAE, Institut Agro, Université de Rennes, Domaine de la Motte, 35653 Le Rheu, France
| | - Benjamin Istace
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 2 rue Gaston Crémieux, 91057 Evry, France
| | - Corinne Cruaud
- Genoscope, Institut François Jacob, Commissariat à l'Energie Atomique (CEA), Université Paris-Saclay, 2 rue Gaston Crémieux, 91057 Evry, France
| | - Cyril Falentin
- IGEPP, INRAE, Institut Agro, Université de Rennes, Domaine de la Motte, 35653 Le Rheu, France
| | - Franz Boideau
- IGEPP, INRAE, Institut Agro, Université de Rennes, Domaine de la Motte, 35653 Le Rheu, France
| | - Julien Boutte
- IGEPP, INRAE, Institut Agro, Université de Rennes, Domaine de la Motte, 35653 Le Rheu, France
| | - Regine Delourme
- IGEPP, INRAE, Institut Agro, Université de Rennes, Domaine de la Motte, 35653 Le Rheu, France
| | - Gwenaëlle Deniot
- IGEPP, INRAE, Institut Agro, Université de Rennes, Domaine de la Motte, 35653 Le Rheu, France
| | - Stefan Engelen
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 2 rue Gaston Crémieux, 91057 Evry, France
| | | | - Arnaud Lemainque
- Genoscope, Institut François Jacob, Commissariat à l'Energie Atomique (CEA), Université Paris-Saclay, 2 rue Gaston Crémieux, 91057 Evry, France
| | - Loeiz Maillet
- IGEPP, INRAE, Institut Agro, Université de Rennes, Domaine de la Motte, 35653 Le Rheu, France
| | - Jérôme Morice
- IGEPP, INRAE, Institut Agro, Université de Rennes, Domaine de la Motte, 35653 Le Rheu, France
| | - Patrick Wincker
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 2 rue Gaston Crémieux, 91057 Evry, France
| | - France Denoeud
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 2 rue Gaston Crémieux, 91057 Evry, France
| | - Anne-Marie Chèvre
- IGEPP, INRAE, Institut Agro, Université de Rennes, Domaine de la Motte, 35653 Le Rheu, France
| | - Jean-Marc Aury
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 2 rue Gaston Crémieux, 91057 Evry, France
| |
Collapse
|
11
|
Jiang J. Fluorescence in situ hybridization in plants: recent developments and future applications. Chromosome Res 2019; 27:153-165. [PMID: 30852707 DOI: 10.1007/s00425-00018-03033-00424] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 02/27/2019] [Accepted: 03/01/2019] [Indexed: 05/20/2023]
Abstract
Fluorescence in situ hybridization (FISH) was developed more than 30 years ago and has been the most paradigm-changing technique in cytogenetic research. FISH has been used to answer questions related to structure, mutation, and evolution of not only individual chromosomes but also entire genomes. FISH has served as an important tool for chromosome identification in many plant species. This review intends to summarize and discuss key technical development and applications of FISH in plants since 2006. The most significant recent advance of FISH is the development and application of probes based on synthetic oligonucleotides (oligos). Oligos specific to a repetitive DNA sequence, to a specific chromosomal region, or to an entire chromosome can be computationally identified, synthesized in parallel, and fluorescently labeled. Oligo probes designed from conserved DNA sequences from one species can be used among genetically related species, allowing comparative cytogenetic mapping of these species. The advances with synthetic oligo probes will significantly expand the applications of FISH especially in non-model plant species. Recent achievements and future applications of FISH and oligo-FISH are discussed.
Collapse
Affiliation(s)
- Jiming Jiang
- Department of Plant Biology, Department of Horticulture, Michigan State University, East Lansing, MI, 48824, USA.
| |
Collapse
|
12
|
Jiang J. Fluorescence in situ hybridization in plants: recent developments and future applications. Chromosome Res 2019; 27:153-165. [PMID: 30852707 DOI: 10.1007/s10577-019-09607-z] [Citation(s) in RCA: 94] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 02/27/2019] [Accepted: 03/01/2019] [Indexed: 01/20/2023]
Abstract
Fluorescence in situ hybridization (FISH) was developed more than 30 years ago and has been the most paradigm-changing technique in cytogenetic research. FISH has been used to answer questions related to structure, mutation, and evolution of not only individual chromosomes but also entire genomes. FISH has served as an important tool for chromosome identification in many plant species. This review intends to summarize and discuss key technical development and applications of FISH in plants since 2006. The most significant recent advance of FISH is the development and application of probes based on synthetic oligonucleotides (oligos). Oligos specific to a repetitive DNA sequence, to a specific chromosomal region, or to an entire chromosome can be computationally identified, synthesized in parallel, and fluorescently labeled. Oligo probes designed from conserved DNA sequences from one species can be used among genetically related species, allowing comparative cytogenetic mapping of these species. The advances with synthetic oligo probes will significantly expand the applications of FISH especially in non-model plant species. Recent achievements and future applications of FISH and oligo-FISH are discussed.
Collapse
Affiliation(s)
- Jiming Jiang
- Department of Plant Biology, Department of Horticulture, Michigan State University, East Lansing, MI, 48824, USA.
| |
Collapse
|
13
|
Re-exploration of U's Triangle Brassica Species Based on Chloroplast Genomes and 45S nrDNA Sequences. Sci Rep 2018; 8:7353. [PMID: 29743507 PMCID: PMC5943242 DOI: 10.1038/s41598-018-25585-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 04/24/2018] [Indexed: 12/31/2022] Open
Abstract
The concept of U's triangle, which revealed the importance of polyploidization in plant genome evolution, described natural allopolyploidization events in Brassica using three diploids [B. rapa (A genome), B. nigra (B), and B. oleracea (C)] and derived allotetraploids [B. juncea (AB genome), B. napus (AC), and B. carinata (BC)]. However, comprehensive understanding of Brassica genome evolution has not been fully achieved. Here, we performed low-coverage (2-6×) whole-genome sequencing of 28 accessions of Brassica as well as of Raphanus sativus [R genome] to explore the evolution of six Brassica species based on chloroplast genome and ribosomal DNA variations. Our phylogenomic analyses led to two main conclusions. (1) Intra-species-level chloroplast genome variations are low in the three allotetraploids (2~7 SNPs), but rich and variable in each diploid species (7~193 SNPs). (2) Three allotetraploids maintain two 45SnrDNA types derived from both ancestral species with maternal dominance. Furthermore, this study sheds light on the maternal origin of the AC chloroplast genome. Overall, this study clarifies the genetic relationships of U's triangle species based on a comprehensive genomics approach and provides important genomic resources for correlative and evolutionary studies.
Collapse
|