1
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Heitkam T, Schulte L, Weber B, Liedtke S, Breitenbach S, Kögler A, Morgenstern K, Brückner M, Tröber U, Wolf H, Krabel D, Schmidt T. Comparative Repeat Profiling of Two Closely Related Conifers ( Larix decidua and Larix kaempferi) Reveals High Genome Similarity With Only Few Fast-Evolving Satellite DNAs. Front Genet 2021; 12:683668. [PMID: 34322154 PMCID: PMC8312256 DOI: 10.3389/fgene.2021.683668] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Accepted: 05/25/2021] [Indexed: 12/26/2022] Open
Abstract
In eukaryotic genomes, cycles of repeat expansion and removal lead to large-scale genomic changes and propel organisms forward in evolution. However, in conifers, active repeat removal is thought to be limited, leading to expansions of their genomes, mostly exceeding 10 giga base pairs. As a result, conifer genomes are largely littered with fragmented and decayed repeats. Here, we aim to investigate how the repeat landscapes of two related conifers have diverged, given the conifers' accumulative genome evolution mode. For this, we applied low-coverage sequencing and read clustering to the genomes of European and Japanese larch, Larix decidua (Lamb.) Carrière and Larix kaempferi (Mill.), that arose from a common ancestor, but are now geographically isolated. We found that both Larix species harbored largely similar repeat landscapes, especially regarding the transposable element content. To pin down possible genomic changes, we focused on the repeat class with the fastest sequence turnover: satellite DNAs (satDNAs). Using comparative bioinformatics, Southern, and fluorescent in situ hybridization, we reveal the satDNAs' organizational patterns, their abundances, and chromosomal locations. Four out of the five identified satDNAs are widespread in the Larix genus, with two even present in the more distantly related Pseudotsuga and Abies genera. Unexpectedly, the EulaSat3 family was restricted to L. decidua and absent from L. kaempferi, indicating its evolutionarily young age. Taken together, our results exemplify how the accumulative genome evolution of conifers may limit the overall divergence of repeats after speciation, producing only few repeat-induced genomic novelties.
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Affiliation(s)
- Tony Heitkam
- Institute of Botany, Technische Universität Dresden, Dresden, Germany
| | - Luise Schulte
- Institute of Botany, Technische Universität Dresden, Dresden, Germany.,Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany
| | - Beatrice Weber
- Institute of Botany, Technische Universität Dresden, Dresden, Germany
| | - Susan Liedtke
- Institute of Botany, Technische Universität Dresden, Dresden, Germany
| | - Sarah Breitenbach
- Institute of Botany, Technische Universität Dresden, Dresden, Germany
| | - Anja Kögler
- Institute of Botany, Technische Universität Dresden, Dresden, Germany
| | - Kristin Morgenstern
- Institute of Forest Botany and Forest Zoology, Technische Universität Dresden, Tharandt, Germany
| | | | - Ute Tröber
- Staatsbetrieb Sachsenforst, Pirna, Germany
| | - Heino Wolf
- Staatsbetrieb Sachsenforst, Pirna, Germany
| | - Doris Krabel
- Institute of Forest Botany and Forest Zoology, Technische Universität Dresden, Tharandt, Germany
| | - Thomas Schmidt
- Institute of Botany, Technische Universität Dresden, Dresden, Germany
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2
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Shang J, Tian J, Cheng H, Yan Q, Li L, Jamal A, Xu Z, Xiang L, Saski CA, Jin S, Zhao K, Liu X, Chen L. The chromosome-level wintersweet (Chimonanthus praecox) genome provides insights into floral scent biosynthesis and flowering in winter. Genome Biol 2020; 21:200. [PMID: 32778152 PMCID: PMC7419205 DOI: 10.1186/s13059-020-02088-y] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 06/29/2020] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Wintersweet (Chimonanthus praecox), an important ornamental plant, has evolved unique fragrant aroma and winter-flowering properties, which are critical for its successful sexual reproduction. However, the molecular mechanisms underlying these traits are largely unknown in this species. In addition, wintersweet is also a typical representative species of the magnoliids, where the phylogenetic position of which relative to eudicots and monocots has not been conclusively resolved. RESULTS Here, we present a chromosome-level wintersweet genome assembly with a total size of 695.36 Mb and a draft genome assembly of Calycanthus chinensis. Phylogenetic analyses of 17 representative angiosperm genomes suggest that Magnoliids and eudicots are sister to monocots. Whole-genome duplication signatures reveal two major duplication events in the evolutionary history of the wintersweet genome, with an ancient one shared by Laurales, and a more recent one shared by the Calycantaceae. Whole-genome duplication and tandem duplication events have significant impacts on copy numbers of genes related to terpene and benzenoid/phenylpropanoid (the main floral scent volatiles) biosynthesis, which may contribute to the characteristic aroma formation. An integrative analysis combining cytology with genomic and transcriptomic data reveals biological characteristics of wintersweet, such as floral transition in spring, floral organ specification, low temperature-mediated floral bud break, early blooming in winter, and strong cold tolerance. CONCLUSIONS These findings provide insights into the evolutionary history of wintersweet and the relationships among the Magnoliids, monocots, and eudicots; the molecular basis underlying floral scent biosynthesis; and winter flowering, and highlight the utility of multi-omics data in deciphering important ornamental traits in wintersweet.
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Affiliation(s)
- Junzhong Shang
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, Hubei 430070 People’s Republic of China
| | - Jingpu Tian
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, Hubei 430070 People’s Republic of China
| | - Huihui Cheng
- Novogene Bioinformatics Institute, Beijing, 100083 People’s Republic of China
| | - Qiaomu Yan
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, Hubei 430070 People’s Republic of China
| | - Lai Li
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, Hubei 430070 People’s Republic of China
| | - Abbas Jamal
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, Hubei 430070 People’s Republic of China
| | - Zhongping Xu
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070 People’s Republic of China
- Xinjiang Production and Construction Corps Key Laboratory of Protection and Utilization of Biological Resources in Tarim Basin, Tarim University, Alaer, Xinjiang, 843300 China
| | - Lin Xiang
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, Hubei 430070 People’s Republic of China
| | | | - Shuangxia Jin
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei 430070 People’s Republic of China
- Xinjiang Production and Construction Corps Key Laboratory of Protection and Utilization of Biological Resources in Tarim Basin, Tarim University, Alaer, Xinjiang, 843300 China
| | - Kaige Zhao
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, Hubei 430070 People’s Republic of China
| | - Xiuqun Liu
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, Wuhan, Hubei 430070 People’s Republic of China
| | - Longqing Chen
- Southwest Engineering Technology and Research Center of Landscape Architecture, State Forestry Administration, Southwest Forestry University, Kunming, Yunnan 650224 People’s Republic of China
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3
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Orozco-Arias S, Isaza G, Guyot R. Retrotransposons in Plant Genomes: Structure, Identification, and Classification through Bioinformatics and Machine Learning. Int J Mol Sci 2019; 20:E3837. [PMID: 31390781 PMCID: PMC6696364 DOI: 10.3390/ijms20153837] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 07/31/2019] [Accepted: 08/02/2019] [Indexed: 01/26/2023] Open
Abstract
Transposable elements (TEs) are genomic units able to move within the genome of virtually all organisms. Due to their natural repetitive numbers and their high structural diversity, the identification and classification of TEs remain a challenge in sequenced genomes. Although TEs were initially regarded as "junk DNA", it has been demonstrated that they play key roles in chromosome structures, gene expression, and regulation, as well as adaptation and evolution. A highly reliable annotation of these elements is, therefore, crucial to better understand genome functions and their evolution. To date, much bioinformatics software has been developed to address TE detection and classification processes, but many problematic aspects remain, such as the reliability, precision, and speed of the analyses. Machine learning and deep learning are algorithms that can make automatic predictions and decisions in a wide variety of scientific applications. They have been tested in bioinformatics and, more specifically for TEs, classification with encouraging results. In this review, we will discuss important aspects of TEs, such as their structure, importance in the evolution and architecture of the host, and their current classifications and nomenclatures. We will also address current methods and their limitations in identifying and classifying TEs.
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Affiliation(s)
- Simon Orozco-Arias
- Department of Computer Science, Universidad Autónoma de Manizales, Manizales 170001, Colombia
- Department of Systems and Informatics, Universidad de Caldas, Manizales 170001, Colombia
| | - Gustavo Isaza
- Department of Systems and Informatics, Universidad de Caldas, Manizales 170001, Colombia
| | - Romain Guyot
- Department of Electronics and Automatization, Universidad Autónoma de Manizales, Manizales 170001, Colombia.
- Institut de Recherche pour le Développement, CIRAD, University Montpellier, 34000 Montpellier, France.
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4
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Cossu RM, Casola C, Giacomello S, Vidalis A, Scofield DG, Zuccolo A. LTR Retrotransposons Show Low Levels of Unequal Recombination and High Rates of Intraelement Gene Conversion in Large Plant Genomes. Genome Biol Evol 2018; 9:3449-3462. [PMID: 29228262 PMCID: PMC5751070 DOI: 10.1093/gbe/evx260] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/07/2017] [Indexed: 12/29/2022] Open
Abstract
The accumulation and removal of transposable elements (TEs) is a major driver of genome size evolution in eukaryotes. In plants, long terminal repeat (LTR) retrotransposons (LTR-RTs) represent the majority of TEs and form most of the nuclear DNA in large genomes. Unequal recombination (UR) between LTRs leads to removal of intervening sequence and formation of solo-LTRs. UR is a major mechanism of LTR-RT removal in many angiosperms, but our understanding of LTR-RT-associated recombination within the large, LTR-RT-rich genomes of conifers is quite limited. We employ a novel read-based methodology to estimate the relative rates of LTR-RT-associated UR within the genomes of four conifer and seven angiosperm species. We found the lowest rates of UR in the largest genomes studied, conifers and the angiosperm maize. Recombination may also resolve as gene conversion, which does not remove sequence, so we analyzed LTR-RT-associated gene conversion events (GCEs) in Norway spruce and six angiosperms. Opposite the trend for UR, we found the highest rates of GCEs in Norway spruce and maize. Unlike previous work in angiosperms, we found no evidence that rates of UR correlate with retroelement structural features in the conifers, suggesting that another process is suppressing UR in these species. Recent results from diverse eukaryotes indicate that heterochromatin affects the resolution of recombination, by favoring gene conversion over crossing-over, similar to our observation of opposed rates of UR and GCEs. Control of LTR-RT proliferation via formation of heterochromatin would be a likely step toward large genomes in eukaryotes carrying high LTR-RT content.
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Affiliation(s)
- Rosa Maria Cossu
- Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, Italy.,Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia (IIT), Genova, Italy
| | - Claudio Casola
- Department of Ecosystem Science and Management, Texas A&M University
| | - Stefania Giacomello
- Science for Life Laboratory, School of Biotechnology, Royal Institute of Technology, Solna, Sweden.,Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Solna, Sweden
| | - Amaryllis Vidalis
- Department of Ecology and Environmental Science, Umeå University, Sweden.,Section of Population Epigenetics and Epigenomics, Center of Life and Food Sciences Weihenstephan, Technische Universität München, Freising, Germany
| | - Douglas G Scofield
- Department of Ecology and Environmental Science, Umeå University, Sweden.,Department of Ecology and Genetics: Evolutionary Biology, Uppsala University, Sweden.,Uppsala Multidisciplinary Center for Advanced Computational Science, Uppsala University, Sweden
| | - Andrea Zuccolo
- Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, Italy.,Istituto di Genomica Applicata, Udine, Italy
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5
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Cañas RA, Li Z, Pascual MB, Castro-Rodríguez V, Ávila C, Sterck L, Van de Peer Y, Cánovas FM. The gene expression landscape of pine seedling tissues. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 91:1064-1087. [PMID: 28635135 DOI: 10.1111/tpj.13617] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Revised: 05/13/2017] [Accepted: 05/31/2017] [Indexed: 05/20/2023]
Abstract
Conifers dominate vast regions of the Northern hemisphere. They are the main source of raw materials for timber industry as well as a wide range of biomaterials. Despite their inherent difficulties as experimental models for classical plant biology research, the technological advances in genomics research are enabling fundamental studies on these plants. The use of laser capture microdissection followed by transcriptomic analysis is a powerful tool for unravelling the molecular and functional organization of conifer tissues and specialized cells. In the present work, 14 different tissues from 1-month-old maritime pine (Pinus pinaster) seedlings have been isolated and their transcriptomes analysed. The results increased the sequence information and number of full-length transcripts from a previous reference transcriptome and added 39 841 new transcripts. In total, 2376 transcripts were ubiquitously expressed in all of the examined tissues. These transcripts could be considered the core 'housekeeping genes' in pine. The genes have been clustered in function to their expression profiles. This analysis reduced the number of profiles to 38, most of these defined by their expression in a unique tissue that is much higher than in the other tissues. The expression and localization data are accessible at ConGenIE.org (http://v22.popgenie.org/microdisection/). This study presents an overview of the gene expression distribution in different pine tissues, specifically highlighting the relationships between tissue gene expression and function. This transcriptome atlas is a valuable resource for functional genomics research in conifers.
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Affiliation(s)
- Rafael A Cañas
- Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Campus Universitario de Teatinos s/n, 29071, Málaga, Spain
| | - Zhen Li
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 927, B-9052, Ghent, Belgium
- Center for Plant Systems Biology, VIB, B-9052, Ghent, Belgium
- Bioinformatics Institute Ghent, Ghent University, Technologiepark 927, B-9052, Ghent, Belgium
| | - M Belén Pascual
- Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Campus Universitario de Teatinos s/n, 29071, Málaga, Spain
| | - Vanessa Castro-Rodríguez
- Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Campus Universitario de Teatinos s/n, 29071, Málaga, Spain
| | - Concepción Ávila
- Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Campus Universitario de Teatinos s/n, 29071, Málaga, Spain
| | - Lieven Sterck
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 927, B-9052, Ghent, Belgium
- Center for Plant Systems Biology, VIB, B-9052, Ghent, Belgium
- Bioinformatics Institute Ghent, Ghent University, Technologiepark 927, B-9052, Ghent, Belgium
| | - Yves Van de Peer
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 927, B-9052, Ghent, Belgium
- Center for Plant Systems Biology, VIB, B-9052, Ghent, Belgium
- Bioinformatics Institute Ghent, Ghent University, Technologiepark 927, B-9052, Ghent, Belgium
| | - Francisco M Cánovas
- Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Campus Universitario de Teatinos s/n, 29071, Málaga, Spain
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6
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Yao J, Xiaoyu L, Cheng P, Yeyun L, Jiayue J, Changjun J. Cloning and analysis of reverse transcriptases from Ty1- copia retrotransposons in Camellia sinensis. BIOTECHNOL BIOTEC EQ 2017. [DOI: 10.1080/13102818.2017.1332492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Affiliation(s)
- Jin Yao
- State Key Laboratory of Tea Plant Biology and Utilization, College of Tea and Food Technology, Anhui Agricultural University, Hefei, PR China
| | - Li Xiaoyu
- State Key Laboratory of Tea Plant Biology and Utilization, College of Tea and Food Technology, Anhui Agricultural University, Hefei, PR China
- Department of Biological Resources, School of Life Science and Environmental Science, Huangshan University, Huangshan, PR China
| | - Pan Cheng
- State Key Laboratory of Tea Plant Biology and Utilization, College of Tea and Food Technology, Anhui Agricultural University, Hefei, PR China
| | - Li Yeyun
- State Key Laboratory of Tea Plant Biology and Utilization, College of Tea and Food Technology, Anhui Agricultural University, Hefei, PR China
| | - Jiang Jiayue
- State Key Laboratory of Tea Plant Biology and Utilization, College of Tea and Food Technology, Anhui Agricultural University, Hefei, PR China
| | - Jiang Changjun
- State Key Laboratory of Tea Plant Biology and Utilization, College of Tea and Food Technology, Anhui Agricultural University, Hefei, PR China
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7
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Guan R, Zhao Y, Zhang H, Fan G, Liu X, Zhou W, Shi C, Wang J, Liu W, Liang X, Fu Y, Ma K, Zhao L, Zhang F, Lu Z, Lee SMY, Xu X, Wang J, Yang H, Fu C, Ge S, Chen W. Draft genome of the living fossil Ginkgo biloba. Gigascience 2016. [PMID: 27871309 DOI: 10.1186/s13742-016-0154-1pmid:27871309] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023] Open
Abstract
BACKGROUND Ginkgo biloba L. (Ginkgoaceae) is one of the most distinctive plants. It possesses a suite of fascinating characteristics including a large genome, outstanding resistance/tolerance to abiotic and biotic stresses, and dioecious reproduction, making it an ideal model species for biological studies. However, the lack of a high-quality genome sequence has been an impediment to our understanding of its biology and evolution. FINDINGS The 10.61 Gb genome sequence containing 41,840 annotated genes was assembled in the present study. Repetitive sequences account for 76.58% of the assembled sequence, and long terminal repeat retrotransposons (LTR-RTs) are particularly prevalent. The diversity and abundance of LTR-RTs is due to their gradual accumulation and a remarkable amplification between 16 and 24 million years ago, and they contribute to the long introns and large genome. Whole genome duplication (WGD) may have occurred twice, with an ancient WGD consistent with that shown to occur in other seed plants, and a more recent event specific to ginkgo. Abundant gene clusters from tandem duplication were also evident, and enrichment of expanded gene families indicates a remarkable array of chemical and antibacterial defense pathways. CONCLUSIONS The ginkgo genome consists mainly of LTR-RTs resulting from ancient gradual accumulation and two WGD events. The multiple defense mechanisms underlying the characteristic resilience of ginkgo are fostered by a remarkable enrichment in ancient duplicated and ginkgo-specific gene clusters. The present study sheds light on sequencing large genomes, and opens an avenue for further genetic and evolutionary research.
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Affiliation(s)
- Rui Guan
- BGI-Shenzhen, Shenzhen, 518083, China
- BGI-Qingdao, Qingdao, 266555, China
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, China
| | - Yunpeng Zhao
- The Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
- Laboratory of Systematic & Evolutionary Botany and Biodiversity, Institute of Ecology and Conservation Center for Gene Resources of Endangered Wildlife, Zhejiang University, Hangzhou, 310058, China
| | - He Zhang
- BGI-Shenzhen, Shenzhen, 518083, China
- BGI-Qingdao, Qingdao, 266555, China
- Stanley Ho Centre for Emerging Infectious Diseases, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Guangyi Fan
- BGI-Shenzhen, Shenzhen, 518083, China
- BGI-Qingdao, Qingdao, 266555, China
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, Macao, China
| | - Xin Liu
- BGI-Shenzhen, Shenzhen, 518083, China
| | - Wenbin Zhou
- The Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
- Laboratory of Systematic & Evolutionary Botany and Biodiversity, Institute of Ecology and Conservation Center for Gene Resources of Endangered Wildlife, Zhejiang University, Hangzhou, 310058, China
| | | | | | - Weiqing Liu
- BGI-Wuhan, BGI-Shenzhen, Wuhan, 430074, China
| | | | - Yuanyuan Fu
- BGI-Shenzhen, Shenzhen, 518083, China
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, China
| | | | - Lijun Zhao
- The Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
- Laboratory of Systematic & Evolutionary Botany and Biodiversity, Institute of Ecology and Conservation Center for Gene Resources of Endangered Wildlife, Zhejiang University, Hangzhou, 310058, China
| | - Fumin Zhang
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Zuhong Lu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, China
| | - Simon Ming-Yuen Lee
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, Macao, China
| | - Xun Xu
- BGI-Shenzhen, Shenzhen, 518083, China
| | - Jian Wang
- BGI-Shenzhen, Shenzhen, 518083, China
- James D. Watson Institute of Genome Sciences, Hangzhou, 310058, China
| | - Huanming Yang
- BGI-Shenzhen, Shenzhen, 518083, China
- James D. Watson Institute of Genome Sciences, Hangzhou, 310058, China
| | - Chengxin Fu
- The Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China.
- Laboratory of Systematic & Evolutionary Botany and Biodiversity, Institute of Ecology and Conservation Center for Gene Resources of Endangered Wildlife, Zhejiang University, Hangzhou, 310058, China.
| | - Song Ge
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
| | - Wenbin Chen
- BGI-Shenzhen, Shenzhen, 518083, China.
- BGI-Qingdao, Qingdao, 266555, China.
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8
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Guan R, Zhao Y, Zhang H, Fan G, Liu X, Zhou W, Shi C, Wang J, Liu W, Liang X, Fu Y, Ma K, Zhao L, Zhang F, Lu Z, Lee SMY, Xu X, Wang J, Yang H, Fu C, Ge S, Chen W. Draft genome of the living fossil Ginkgo biloba. Gigascience 2016; 5:49. [PMID: 27871309 PMCID: PMC5118899 DOI: 10.1186/s13742-016-0154-1] [Citation(s) in RCA: 156] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 11/01/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Ginkgo biloba L. (Ginkgoaceae) is one of the most distinctive plants. It possesses a suite of fascinating characteristics including a large genome, outstanding resistance/tolerance to abiotic and biotic stresses, and dioecious reproduction, making it an ideal model species for biological studies. However, the lack of a high-quality genome sequence has been an impediment to our understanding of its biology and evolution. FINDINGS The 10.61 Gb genome sequence containing 41,840 annotated genes was assembled in the present study. Repetitive sequences account for 76.58% of the assembled sequence, and long terminal repeat retrotransposons (LTR-RTs) are particularly prevalent. The diversity and abundance of LTR-RTs is due to their gradual accumulation and a remarkable amplification between 16 and 24 million years ago, and they contribute to the long introns and large genome. Whole genome duplication (WGD) may have occurred twice, with an ancient WGD consistent with that shown to occur in other seed plants, and a more recent event specific to ginkgo. Abundant gene clusters from tandem duplication were also evident, and enrichment of expanded gene families indicates a remarkable array of chemical and antibacterial defense pathways. CONCLUSIONS The ginkgo genome consists mainly of LTR-RTs resulting from ancient gradual accumulation and two WGD events. The multiple defense mechanisms underlying the characteristic resilience of ginkgo are fostered by a remarkable enrichment in ancient duplicated and ginkgo-specific gene clusters. The present study sheds light on sequencing large genomes, and opens an avenue for further genetic and evolutionary research.
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Affiliation(s)
- Rui Guan
- BGI-Shenzhen, Shenzhen, 518083, China
- BGI-Qingdao, Qingdao, 266555, China
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, China
| | - Yunpeng Zhao
- The Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
- Laboratory of Systematic & Evolutionary Botany and Biodiversity, Institute of Ecology and Conservation Center for Gene Resources of Endangered Wildlife, Zhejiang University, Hangzhou, 310058, China
| | - He Zhang
- BGI-Shenzhen, Shenzhen, 518083, China
- BGI-Qingdao, Qingdao, 266555, China
- Stanley Ho Centre for Emerging Infectious Diseases, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Guangyi Fan
- BGI-Shenzhen, Shenzhen, 518083, China
- BGI-Qingdao, Qingdao, 266555, China
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, Macao, China
| | - Xin Liu
- BGI-Shenzhen, Shenzhen, 518083, China
| | - Wenbin Zhou
- The Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
- Laboratory of Systematic & Evolutionary Botany and Biodiversity, Institute of Ecology and Conservation Center for Gene Resources of Endangered Wildlife, Zhejiang University, Hangzhou, 310058, China
| | | | | | - Weiqing Liu
- BGI-Wuhan, BGI-Shenzhen, Wuhan, 430074, China
| | | | - Yuanyuan Fu
- BGI-Shenzhen, Shenzhen, 518083, China
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, China
| | | | - Lijun Zhao
- The Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
- Laboratory of Systematic & Evolutionary Botany and Biodiversity, Institute of Ecology and Conservation Center for Gene Resources of Endangered Wildlife, Zhejiang University, Hangzhou, 310058, China
| | - Fumin Zhang
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Zuhong Lu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, China
| | - Simon Ming-Yuen Lee
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, Macao, China
| | - Xun Xu
- BGI-Shenzhen, Shenzhen, 518083, China
| | - Jian Wang
- BGI-Shenzhen, Shenzhen, 518083, China
- James D. Watson Institute of Genome Sciences, Hangzhou, 310058, China
| | - Huanming Yang
- BGI-Shenzhen, Shenzhen, 518083, China
- James D. Watson Institute of Genome Sciences, Hangzhou, 310058, China
| | - Chengxin Fu
- The Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China.
- Laboratory of Systematic & Evolutionary Botany and Biodiversity, Institute of Ecology and Conservation Center for Gene Resources of Endangered Wildlife, Zhejiang University, Hangzhou, 310058, China.
| | - Song Ge
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
| | - Wenbin Chen
- BGI-Shenzhen, Shenzhen, 518083, China.
- BGI-Qingdao, Qingdao, 266555, China.
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Abstract
Until very recently, complete characterization of the megagenomes of conifers has remained elusive. The diploid genome of sugar pine (Pinus lambertiana Dougl.) has a highly repetitive, 31 billion bp genome. It is the largest genome sequenced and assembled to date, and the first from the subgenus Strobus, or white pines, a group that is notable for having the largest genomes among the pines. The genome represents a unique opportunity to investigate genome "obesity" in conifers and white pines. Comparative analysis of P. lambertiana and P. taeda L. reveals new insights on the conservation, age, and diversity of the highly abundant transposable elements, the primary factor determining genome size. Like most North American white pines, the principal pathogen of P. lambertiana is white pine blister rust (Cronartium ribicola J.C. Fischer ex Raben.). Identification of candidate genes for resistance to this pathogen is of great ecological importance. The genome sequence afforded us the opportunity to make substantial progress on locating the major dominant gene for simple resistance hypersensitive response, Cr1 We describe new markers and gene annotation that are both tightly linked to Cr1 in a mapping population, and associated with Cr1 in unrelated sugar pine individuals sampled throughout the species' range, creating a solid foundation for future mapping. This genomic variation and annotated candidate genes characterized in our study of the Cr1 region are resources for future marker-assisted breeding efforts as well as for investigations of fundamental mechanisms of invasive disease and evolutionary response.
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10
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Lwin AK, Bertolini E, Pè ME, Zuccolo A. Genomic skimming for identification of medium/highly abundant transposable elements in Arundo donax and Arundo plinii. Mol Genet Genomics 2016; 292:157-171. [PMID: 27778102 DOI: 10.1007/s00438-016-1263-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 10/17/2016] [Indexed: 11/29/2022]
Abstract
Transposable elements (TEs) are the most abundant genetic material for almost all eukaryotic genomes. Their effects on the host genomes range from an extensive size variation to the regulation of gene expression, altering gene function and creating new genes. Because of TEs pivotal contribute to the host genome structure and regulation, their identification and characterization provide a wealth of useful data for gaining an in-depth understanding of host genome functioning. The giant reed (Arundo donax) is a perennial rhizomatous C3 grass, octadecaploid, with an estimated nuclear genome size of 2744 Mbp. It is a promising feedstock for second-generation biofuels and biomethane production. To identify and characterize the most repetitive TEs in the genomes of A. donax and its ancestral A. plinii species, we carried out low-coverage whole genome shotgun sequencing for both species. Using a de novo repeat identification approach, 33,041 and 28,237 non-redundant repetitive sequences were identified and characterized in A. donax and A. plinii genomes, representing 37.55 and 31.68% of each genome, respectively. Comparative phylogenetic analyses, including the major TE classes identified in A. donax and A. plinii, together with rice and maize TE paralogs, were carried out to understand the evolutionary relationship of the most abundant TE classes. Highly conserved copies of RIRE1-like Ty1-Copia elements were discovered in two Arundo spp. in which they represented nearly 3% of each genomic sequence. We identified and characterized the medium/highly repetitive TEs in two unexplored polyploid genomes, thus generating useful information for the study of the genomic structure, composition, and functioning of these two non-model species. We provided a valuable resource that could be exploited in any effort aimed at sequencing and assembling these two genomes.
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Affiliation(s)
- Aung Kyaw Lwin
- Institute of Life Sciences, Scuola Superiore Sant'Anna, Piazza Martiri della Libertà, 33, 56127, Pisa, Italy.,Sugarcane Research and Seed Farm, Pyinmana, Nay Pyi Taw, Myanmar
| | - Edoardo Bertolini
- Institute of Life Sciences, Scuola Superiore Sant'Anna, Piazza Martiri della Libertà, 33, 56127, Pisa, Italy
| | - Mario Enrico Pè
- Institute of Life Sciences, Scuola Superiore Sant'Anna, Piazza Martiri della Libertà, 33, 56127, Pisa, Italy
| | - Andrea Zuccolo
- Institute of Life Sciences, Scuola Superiore Sant'Anna, Piazza Martiri della Libertà, 33, 56127, Pisa, Italy.
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11
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Fawcett JA, Innan H. High Similarity between Distantly Related Species of a Plant SINE Family Is Consistent with a Scenario of Vertical Transmission without Horizontal Transfers. Mol Biol Evol 2016; 33:2593-604. [PMID: 27436006 DOI: 10.1093/molbev/msw130] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Many transposable element (TE) families show surprisingly high levels of similarity between distantly related species. This high similarity, coupled with a "patchy" phylogenetic distribution, has often been attributed to frequent horizontal transfers of TEs between species, even though the mechanistic basis tends to be speculative. Here, we studied the evolution of the Au SINE (Short INterspersed Element) family, in which high similarity between distantly related plant species has been reported. We were able to identify several copies present in orthologous regions of various species, including species that diverged ∼90 Ma, thereby confirming the presence of Au SINE at multiple evolutionary time points. We also found that the Au SINE has been degenerating and is en route to disappearing in many species, indicating that the loss of Au SINE is common. Our results suggest that the evolution of the Au SINE can be readily explained by a scenario of vertical transmission without having to invoke hypothetical scenarios of rampant horizontal transfers. The Au SINE was likely present in the common ancestor of all angiosperms and was retained in some lineages while lost from others. The high level of conservation is probably because the sequences were important for ensuring their transpositional activity. This model of TE evolution should provide a basic framework for understanding the evolution of TEs in general.
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Affiliation(s)
- Jeffrey A Fawcett
- SOKENDAI (The Graduate University for Advanced Studies), Hayama, Kanagawa, Japan
| | - Hideki Innan
- SOKENDAI (The Graduate University for Advanced Studies), Hayama, Kanagawa, Japan
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12
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Gebre YG, Bertolini E, Pè ME, Zuccolo A. Identification and characterization of abundant repetitive sequences in Eragrostis tef cv. Enatite genome. BMC PLANT BIOLOGY 2016; 16:39. [PMID: 26833063 PMCID: PMC4736629 DOI: 10.1186/s12870-016-0725-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 01/28/2016] [Indexed: 06/05/2023]
Abstract
BACKGROUND Eragrostis tef is an allotetraploid (2n = 4 × = 40) annual, C4 grass with an estimated nuclear genome size of 730 Mbp. It is widely grown in Ethiopia, where it provides basic nutrition for more than half of the population. Although a draft assembly of the E. tef genome was made available in 2014, characterization of the repetitive portion of the E. tef genome has not been a subject of a detailed analysis. Repetitive sequences constitute most of the DNA in eukaryotic genomes. Transposable elements are usually the most abundant repetitive component in plant genomes. They contribute to genome size variation, cause mutations, can result in chromosomal rearrangements, and influence gene regulation. An extensive and in depth characterization of the repetitive component is essential in understanding the evolution and function of the genome. RESULTS Using new paired-end sequence data and a de novo repeat identification strategy, we identified the most repetitive elements in the E. tef genome. Putative repeat sequences were annotated based on similarity to known repeat groups in other grasses. Altogether we identified 1,389 medium/highly repetitive sequences that collectively represent about 27% of the teff genome. Phylogenetic analyses of the most important classes of TEs were carried out in a comparative framework including paralog elements from rice and maize. Finally, an abundant tandem repeat accounting for more than 4% of the whole genome was identified and partially characterized. CONCLUSIONS Analyzing a large sample of randomly sheared reads we obtained a library of the repetitive sequences of E. tef. The approach we used was designed to avoid underestimation of repeat contribution; such underestimation is characteristic of whole genome assembly projects. The data collected represent a valuable resource for further analysis of the genome of this important orphan crop.
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Affiliation(s)
- Yohannes Gedamu Gebre
- Institute of Life Sciences, Scuola Superiore Sant'Anna, Piazza Martiri della Libertà, 33-56127, Pisa, Italy.
- Department of Dryland Crop and Horticultural Sciences, College of Dryland Agriculture and Natural Resources, Mekelle University, P.O.Box 231, Mekelle, Ethiopia.
| | - Edoardo Bertolini
- Institute of Life Sciences, Scuola Superiore Sant'Anna, Piazza Martiri della Libertà, 33-56127, Pisa, Italy.
| | - Mario Enrico Pè
- Institute of Life Sciences, Scuola Superiore Sant'Anna, Piazza Martiri della Libertà, 33-56127, Pisa, Italy.
| | - Andrea Zuccolo
- Institute of Life Sciences, Scuola Superiore Sant'Anna, Piazza Martiri della Libertà, 33-56127, Pisa, Italy.
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13
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Macas J, Novák P, Pellicer J, Čížková J, Koblížková A, Neumann P, Fuková I, Doležel J, Kelly LJ, Leitch IJ. In Depth Characterization of Repetitive DNA in 23 Plant Genomes Reveals Sources of Genome Size Variation in the Legume Tribe Fabeae. PLoS One 2015; 10:e0143424. [PMID: 26606051 PMCID: PMC4659654 DOI: 10.1371/journal.pone.0143424] [Citation(s) in RCA: 118] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Accepted: 11/04/2015] [Indexed: 01/30/2023] Open
Abstract
The differential accumulation and elimination of repetitive DNA are key drivers of genome size variation in flowering plants, yet there have been few studies which have analysed how different types of repeats in related species contribute to genome size evolution within a phylogenetic context. This question is addressed here by conducting large-scale comparative analysis of repeats in 23 species from four genera of the monophyletic legume tribe Fabeae, representing a 7.6-fold variation in genome size. Phylogenetic analysis and genome size reconstruction revealed that this diversity arose from genome size expansions and contractions in different lineages during the evolution of Fabeae. Employing a combination of low-pass genome sequencing with novel bioinformatic approaches resulted in identification and quantification of repeats making up 55–83% of the investigated genomes. In turn, this enabled an analysis of how each major repeat type contributed to the genome size variation encountered. Differential accumulation of repetitive DNA was found to account for 85% of the genome size differences between the species, and most (57%) of this variation was found to be driven by a single lineage of Ty3/gypsy LTR-retrotransposons, the Ogre elements. Although the amounts of several other lineages of LTR-retrotransposons and the total amount of satellite DNA were also positively correlated with genome size, their contributions to genome size variation were much smaller (up to 6%). Repeat analysis within a phylogenetic framework also revealed profound differences in the extent of sequence conservation between different repeat types across Fabeae. In addition to these findings, the study has provided a proof of concept for the approach combining recent developments in sequencing and bioinformatics to perform comparative analyses of repetitive DNAs in a large number of non-model species without the need to assemble their genomes.
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Affiliation(s)
- Jiří Macas
- Biology Centre of the Czech Academy of Sciences, Institute of Plant Molecular Biology, České Budějovice, Czech Republic
- * E-mail:
| | - Petr Novák
- Biology Centre of the Czech Academy of Sciences, Institute of Plant Molecular Biology, České Budějovice, Czech Republic
| | - Jaume Pellicer
- Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey, United Kingdom
| | - Jana Čížková
- Institute of Experimental Botany, Olomouc, Centre of the Region Haná for Biotechnological and Agricultural Research, Olomouc, Czech Republic
| | - Andrea Koblížková
- Biology Centre of the Czech Academy of Sciences, Institute of Plant Molecular Biology, České Budějovice, Czech Republic
| | - Pavel Neumann
- Biology Centre of the Czech Academy of Sciences, Institute of Plant Molecular Biology, České Budějovice, Czech Republic
| | - Iva Fuková
- Biology Centre of the Czech Academy of Sciences, Institute of Plant Molecular Biology, České Budějovice, Czech Republic
| | - Jaroslav Doležel
- Institute of Experimental Botany, Olomouc, Centre of the Region Haná for Biotechnological and Agricultural Research, Olomouc, Czech Republic
| | - Laura J. Kelly
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom
| | - Ilia J. Leitch
- Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey, United Kingdom
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