1
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Fang C, Jiang N, Teresi SJ, Platts AE, Agarwal G, Niederhuth C, Edger PP, Jiang J. Dynamics of accessible chromatin regions and subgenome dominance in octoploid strawberry. Nat Commun 2024; 15:2491. [PMID: 38509076 PMCID: PMC10954716 DOI: 10.1038/s41467-024-46861-0] [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: 08/07/2023] [Accepted: 03/12/2024] [Indexed: 03/22/2024] Open
Abstract
Subgenome dominance has been reported in diverse allopolyploid species, where genes from one subgenome are preferentially retained and are more highly expressed than those from other subgenome(s). However, the molecular mechanisms responsible for subgenome dominance remain poorly understood. Here, we develop genome-wide map of accessible chromatin regions (ACRs) in cultivated strawberry (2n = 8x = 56, with A, B, C, D subgenomes). Each ACR is identified as an MNase hypersensitive site (MHS). We discover that the dominant subgenome A contains a greater number of total MHSs and MHS per gene than the submissive B/C/D subgenomes. Subgenome A suffers fewer losses of MHS-related DNA sequences and fewer MHS fragmentations caused by insertions of transposable elements. We also discover that genes and MHSs related to stress response have been preferentially retained in subgenome A. We conclude that preservation of genes and their cognate ACRs, especially those related to stress responses, play a major role in the establishment of subgenome dominance in octoploid strawberry.
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Affiliation(s)
- Chao Fang
- Department of Plant Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Ning Jiang
- Department of Horticulture, Michigan State University, East Lansing, MI, 48824, USA
- Michigan State University AgBioResearch, East Lansing, MI, 48824, USA
- Genetics and Genome Sciences Program, Michigan State University, East Lansing, MI, 48824, USA
| | - Scott J Teresi
- Department of Horticulture, Michigan State University, East Lansing, MI, 48824, USA
- Genetics and Genome Sciences Program, Michigan State University, East Lansing, MI, 48824, USA
| | - Adrian E Platts
- Department of Horticulture, Michigan State University, East Lansing, MI, 48824, USA
| | - Gaurav Agarwal
- Department of Plant Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Chad Niederhuth
- Department of Plant Biology, Michigan State University, East Lansing, MI, 48824, USA
- Michigan State University AgBioResearch, East Lansing, MI, 48824, USA
| | - Patrick P Edger
- Department of Horticulture, Michigan State University, East Lansing, MI, 48824, USA.
- Michigan State University AgBioResearch, East Lansing, MI, 48824, USA.
- Genetics and Genome Sciences Program, Michigan State University, East Lansing, MI, 48824, USA.
| | - Jiming Jiang
- Department of Plant Biology, Michigan State University, East Lansing, MI, 48824, USA.
- Department of Horticulture, Michigan State University, East Lansing, MI, 48824, USA.
- Michigan State University AgBioResearch, East Lansing, MI, 48824, USA.
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2
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Hassan AH, Mokhtar MM, El Allali A. Transposable elements: multifunctional players in the plant genome. FRONTIERS IN PLANT SCIENCE 2024; 14:1330127. [PMID: 38239225 PMCID: PMC10794571 DOI: 10.3389/fpls.2023.1330127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 12/06/2023] [Indexed: 01/22/2024]
Abstract
Transposable elements (TEs) are indispensable components of eukaryotic genomes that play diverse roles in gene regulation, recombination, and environmental adaptation. Their ability to mobilize within the genome leads to gene expression and DNA structure changes. TEs serve as valuable markers for genetic and evolutionary studies and facilitate genetic mapping and phylogenetic analysis. They also provide insight into how organisms adapt to a changing environment by promoting gene rearrangements that lead to new gene combinations. These repetitive sequences significantly impact genome structure, function and evolution. This review takes a comprehensive look at TEs and their applications in biotechnology, particularly in the context of plant biology, where they are now considered "genomic gold" due to their extensive functionalities. The article addresses various aspects of TEs in plant development, including their structure, epigenetic regulation, evolutionary patterns, and their use in gene editing and plant molecular markers. The goal is to systematically understand TEs and shed light on their diverse roles in plant biology.
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Affiliation(s)
- Asmaa H. Hassan
- Bioinformatics Laboratory, College of Computing, Mohammed VI Polytechnic University, Ben Guerir, Morocco
- Agricultural Genetic Engineering Research Institute, Agriculture Research Center, Giza, Egypt
| | - Morad M. Mokhtar
- Bioinformatics Laboratory, College of Computing, Mohammed VI Polytechnic University, Ben Guerir, Morocco
- Agricultural Genetic Engineering Research Institute, Agriculture Research Center, Giza, Egypt
| | - Achraf El Allali
- Bioinformatics Laboratory, College of Computing, Mohammed VI Polytechnic University, Ben Guerir, Morocco
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3
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Ma H, Wang M, Zhang YE, Tan S. The power of "controllers": Transposon-mediated duplicated genes evolve towards neofunctionalization. J Genet Genomics 2023; 50:462-472. [PMID: 37068629 DOI: 10.1016/j.jgg.2023.04.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 04/04/2023] [Accepted: 04/05/2023] [Indexed: 04/19/2023]
Abstract
Since the discovery of the first transposon by Dr. Barbara McClintock, the prevalence and diversity of transposable elements (TEs) have been gradually recognized. As fundamental genetic components, TEs drive organismal evolution not only by contributing functional sequences (e.g., regulatory elements or "controllers" as phrased by Dr. McClintock) but also by shuffling genomic sequences. In the latter respect, TE-mediated gene duplications have contributed to the origination of new genes and attracted extensive interest. In response to the development of this field, we herein attempt to provide an overview of TE-mediated duplication by focusing on common rules emerging across duplications generated by different TE types. Specifically, despite the huge divergence of transposition machinery across TEs, we identify three common features of various TE-mediated duplication mechanisms, including end bypass, template switching, and recurrent transposition. These three features lead to one common functional outcome, namely, TE-mediated duplicates tend to be subjected to exon shuffling and neofunctionalization. Therefore, the intrinsic properties of the mutational mechanism constrain the evolutionary trajectories of these duplicates. We finally discuss the future of this field including an in-depth characterization of both the duplication mechanisms and functions of TE-mediated duplicates.
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Affiliation(s)
- Huijing Ma
- Key Laboratory of Zoological Systematics and Evolution & State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Mengxia Wang
- Key Laboratory of Zoological Systematics and Evolution & State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yong E Zhang
- Key Laboratory of Zoological Systematics and Evolution & State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; CAS Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, Yunnan 650223, China; Chinese Institute for Brain Research, Beijing 102206, China.
| | - Shengjun Tan
- Key Laboratory of Zoological Systematics and Evolution & State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
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4
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Gisby JS, Catoni M. The widespread nature of Pack-TYPE transposons reveals their importance for plant genome evolution. PLoS Genet 2022; 18:e1010078. [PMID: 35202390 PMCID: PMC8903248 DOI: 10.1371/journal.pgen.1010078] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 03/08/2022] [Accepted: 02/06/2022] [Indexed: 11/29/2022] Open
Abstract
Pack-TYPE transposable elements (TEs) are a group of non-autonomous DNA transposons found in plants. These elements can efficiently capture and shuffle coding DNA across the host genome, accelerating the evolution of genes. Despite their relevance for plant genome plasticity, the detection and study of Pack-TYPE TEs are challenging due to the high similarity these elements have with genes. Here, we produced an automated annotation pipeline designed to study Pack-TYPE elements and used it to successfully annotate and analyse more than 10,000 new Pack-TYPE TEs in the rice and maize genomes. Our analysis indicates that Pack-TYPE TEs are an abundant and heterogeneous group of elements. We found that these elements are associated with all main superfamilies of Class II DNA transposons in plants and likely share a similar mechanism to capture new chromosomal DNA sequences. Furthermore, we report examples of the direct contribution of these TEs to coding genes, suggesting a generalised and extensive role of Pack-TYPE TEs in plant genome evolution. Transposable Elements (TEs) are genetic DNA sequences able to move across the genome, and their transposition activity is associated with genome plasticity and gene evolution. However, most of these elements exhibit “selfish” behaviour, meaning that they mainly transpose their own DNA sequence and only exceptionally might rearrange the DNA of coding genes. Pack-TYPE TEs, found in plants, represent an important exception, and they can efficiently capture and shuffle DNA sequences captured from the genome, accelerating the evolution of genes. We provide here the first automatic pipeline designed explicitly for the annotation of Pack-TYPE TEs. We used our approach to systematically investigate Pack-TYPE TEs in the rice and maize reference genomes, and annotated thousands of new elements in these species. We demonstrate that Pack-TYPE elements are abundant in plants and we report several examples of coding genes originated as a consequence of the mobilization of these elements.
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Affiliation(s)
- Jack S. Gisby
- School of Biosciences, University of Birmingham, Birmingham, United Kingdom
- * E-mail: (JSG); (MC)
| | - Marco Catoni
- School of Biosciences, University of Birmingham, Birmingham, United Kingdom
- Institute for Sustainable Plant Protection, National Research Council of Italy, Torino, Italy
- * E-mail: (JSG); (MC)
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5
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Zhang YC, Zhou YF, Cheng Y, Huang JH, Lian JP, Yang L, He RR, Lei MQ, Liu YW, Yuan C, Zhao WL, Xiao S, Chen YQ. Genome-wide analysis and functional annotation of chromatin-enriched noncoding RNAs in rice during somatic cell regeneration. Genome Biol 2022; 23:28. [PMID: 35045887 PMCID: PMC8772118 DOI: 10.1186/s13059-022-02608-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 01/12/2022] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Plants have the remarkable ability to generate callus, a pluripotent cell mass that acquires competence for subsequent tissue regeneration. Global chromatin remodeling is required for this cell fate transition, but how the process is regulated is not fully understood. Chromatin-enriched noncoding RNAs (cheRNAs) are thought to play important roles in maintaining chromatin state. However, whether cheRNAs participate in somatic cell regeneration in plants has not yet been clarified. RESULTS To uncover the characteristics and functions of cheRNAs during somatic cell reprogramming in plants, we systematically investigate cheRNAs during callus induction, proliferation and regeneration in rice. We identify 2284 cheRNAs, most of which are novel long non-coding RNAs or small nucleolar RNAs. These cheRNAs, which are highly conserved across plant species, shuttle between chromatin and the nucleoplasm during somatic cell regeneration. They positively regulate the expression of neighboring genes via specific RNA motifs, which may interact with DNA motifs around cheRNA loci. Large-scale mutant analysis shows that cheRNAs are associated with plant size and seed morphology. Further detailed functional investigation of two che-lncRNAs demonstrates that their loss of function impairs cell dedifferentiation and plant regeneration, highlighting the functions of cheRNAs in regulating the expression of neighboring genes via specific motifs. These findings support cis- regulatory roles of cheRNAs in influencing a variety of rice traits. CONCLUSIONS cheRNAs are a distinct subclass of regulatory non-coding RNAs that are required for somatic cell regeneration and regulate rice traits. Targeting cheRNAs has great potential for crop trait improvement and breeding in future.
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Affiliation(s)
- Yu-Chan Zhang
- Guangdong Provincial Key Laboratory of Plant Resources, State Key Laboratory for Biocontrol, School of Life Science, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China.
- MOE Key Laboratory of Gene Function and Regulation, Sun Yat-sen University, Guangzhou, 510275, People's Republic of China.
| | - Yan-Fei Zhou
- Guangdong Provincial Key Laboratory of Plant Resources, State Key Laboratory for Biocontrol, School of Life Science, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Yu Cheng
- Guangdong Provincial Key Laboratory of Plant Resources, State Key Laboratory for Biocontrol, School of Life Science, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Jia-Hui Huang
- Guangdong Provincial Key Laboratory of Plant Resources, State Key Laboratory for Biocontrol, School of Life Science, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Jian-Ping Lian
- Guangdong Provincial Key Laboratory of Plant Resources, State Key Laboratory for Biocontrol, School of Life Science, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Lu Yang
- Guangdong Provincial Key Laboratory of Plant Resources, State Key Laboratory for Biocontrol, School of Life Science, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Rui-Rui He
- Guangdong Provincial Key Laboratory of Plant Resources, State Key Laboratory for Biocontrol, School of Life Science, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Meng-Qi Lei
- Guangdong Provincial Key Laboratory of Plant Resources, State Key Laboratory for Biocontrol, School of Life Science, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Yu-Wei Liu
- Guangdong Provincial Key Laboratory of Plant Resources, State Key Laboratory for Biocontrol, School of Life Science, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Chao Yuan
- Guangdong Provincial Key Laboratory of Plant Resources, State Key Laboratory for Biocontrol, School of Life Science, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Wen-Long Zhao
- Guangdong Provincial Key Laboratory of Plant Resources, State Key Laboratory for Biocontrol, School of Life Science, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Shi Xiao
- Guangdong Provincial Key Laboratory of Plant Resources, State Key Laboratory for Biocontrol, School of Life Science, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China
| | - Yue-Qin Chen
- Guangdong Provincial Key Laboratory of Plant Resources, State Key Laboratory for Biocontrol, School of Life Science, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China.
- MOE Key Laboratory of Gene Function and Regulation, Sun Yat-sen University, Guangzhou, 510275, People's Republic of China.
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6
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Tan S, Ma H, Wang J, Wang M, Wang M, Yin H, Zhang Y, Zhang X, Shen J, Wang D, Banes GL, Zhang Z, Wu J, Huang X, Chen H, Ge S, Chen CL, Zhang YE. DNA transposons mediate duplications via transposition-independent and -dependent mechanisms in metazoans. Nat Commun 2021; 12:4280. [PMID: 34257290 PMCID: PMC8277862 DOI: 10.1038/s41467-021-24585-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Accepted: 06/23/2021] [Indexed: 01/06/2023] Open
Abstract
Despite long being considered as "junk", transposable elements (TEs) are now accepted as catalysts of evolution. One example is Mutator-like elements (MULEs, one type of terminal inverted repeat DNA TEs, or TIR TEs) capturing sequences as Pack-MULEs in plants. However, their origination mechanism remains perplexing, and whether TIR TEs mediate duplication in animals is almost unexplored. Here we identify 370 Pack-TIRs in 100 animal reference genomes and one Pack-TIR (Ssk-FB4) family in fly populations. We find that single-copy Pack-TIRs are mostly generated via transposition-independent gap filling, and multicopy Pack-TIRs are likely generated by transposition after replication fork switching. We show that a proportion of Pack-TIRs are transcribed and often form chimeras with hosts. We also find that Ssk-FB4s represent a young protein family, as supported by proteomics and signatures of positive selection. Thus, TIR TEs catalyze new gene structures and new genes in animals via both transposition-independent and -dependent mechanisms.
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Affiliation(s)
- Shengjun Tan
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Huijing Ma
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jinbo Wang
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Man Wang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Center for Cancer Bioinformatics, Peking University Cancer Hospital & Institute, Beijing, China
| | - Mengxia Wang
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Haodong Yin
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yaqiong Zhang
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Xinying Zhang
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jieyu Shen
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Danyang Wang
- University of Chinese Academy of Sciences, Beijing, China
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, and China National Center for Bioinformation, Chinese Academy of Sciences, Beijing, China
| | - Graham L Banes
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, WI, USA
- CAS Key Laboratory of Computational Biology, Shanghai Institute of Nutrition and Health, Chinese Academy of Sciences, Shanghai, China
| | - Zhihua Zhang
- University of Chinese Academy of Sciences, Beijing, China
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, and China National Center for Bioinformation, Chinese Academy of Sciences, Beijing, China
| | - Jianmin Wu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Center for Cancer Bioinformatics, Peking University Cancer Hospital & Institute, Beijing, China
| | - Xun Huang
- University of Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Hua Chen
- University of Chinese Academy of Sciences, Beijing, China
- CAS Key Laboratory of Genomics and Precision Medicine, Beijing Institute of Genomics, and China National Center for Bioinformation, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, China
| | - Siqin Ge
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Chun-Long Chen
- Curie Institute, PSL Research University, CNRS UMR 3244, Paris, France.
- Sorbonne University, Paris, France.
| | - Yong E Zhang
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
- University of Chinese Academy of Sciences, Beijing, China.
- CAS Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, China.
- Chinese Institute for Brain Research, Beijing, China.
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7
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Muyle A, Seymour D, Darzentas N, Primetis E, Gaut BS, Bousios A. Gene capture by transposable elements leads to epigenetic conflict in maize. MOLECULAR PLANT 2021; 14:237-252. [PMID: 33171302 DOI: 10.1016/j.molp.2020.11.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 10/15/2020] [Accepted: 11/05/2020] [Indexed: 06/11/2023]
Abstract
Transposable elements (TEs) regularly capture fragments of genes. When the host silences these TEs, siRNAs homologous to the captured regions may also target the genes. This epigenetic crosstalk establishes an intragenomic conflict: silencing the TEs has the cost of silencing the genes. If genes are important, however, natural selection may maintain function by moderating the silencing response, which may also advantage the TEs. In this study, we examined this model by focusing on Helitrons, Pack-MULEs, and Sirevirus LTR retrotransposons in the maize genome. We documented 1263 TEs containing exon fragments from 1629 donor genes. Consistent with epigenetic conflict, donor genes mapped more siRNAs and were more methylated than genes with no evidence of capture. However, these patterns differed between syntelog versus translocated donor genes. Syntelogs appeared to maintain function, as measured by gene expression, consistent with moderation of silencing for functionally important genes. Epigenetic marks did not spread beyond their captured regions and 24nt crosstalk siRNAs were linked with CHH methylation. Translocated genes, in contrast, bore the signature of silencing. They were highly methylated and less expressed, but also overrepresented among donor genes and located away from chromosomal arms, which suggests a link between capture and gene movement. Splitting genes into potential functional categories based on evolutionary constraint supported the synteny-based findings. TE families captured genes in different ways, but the evidence for their advantage was generally less obvious; nevertheless, TEs with captured fragments were older, mapped fewer siRNAs, and were slightly less methylated than TEs without captured fragments. Collectively, our results argue that TE capture triggers an intragenomic conflict that may not affect the function of important genes but may lead to the pseudogenization of less-constrained genes.
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Affiliation(s)
- Aline Muyle
- Department of Ecology and Evolutionary Biology, UC Irvine, Irvine, CA 92697, USA
| | - Danelle Seymour
- Department of Ecology and Evolutionary Biology, UC Irvine, Irvine, CA 92697, USA; Department of Botany and Plant Sciences, UC Riverside, Riverside, CA 92521, USA
| | - Nikos Darzentas
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Elias Primetis
- School of Life Sciences, University of Sussex, Brighton, UK
| | - Brandon S Gaut
- Department of Ecology and Evolutionary Biology, UC Irvine, Irvine, CA 92697, USA.
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8
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Zhang X, Zhao M, McCarty DR, Lisch D. Transposable elements employ distinct integration strategies with respect to transcriptional landscapes in eukaryotic genomes. Nucleic Acids Res 2020; 48:6685-6698. [PMID: 32442316 PMCID: PMC7337890 DOI: 10.1093/nar/gkaa370] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 04/24/2020] [Accepted: 04/29/2020] [Indexed: 12/27/2022] Open
Abstract
Transposable elements (TEs) are ubiquitous DNA segments capable of moving from one site to another within host genomes. The extant distributions of TEs in eukaryotic genomes have been shaped by both bona fide TE integration preferences in eukaryotic genomes and by selection following integration. Here, we compare TE target site distribution in host genomes using multiple de novo transposon insertion datasets in both plants and animals and compare them in the context of genome-wide transcriptional landscapes. We showcase two distinct types of transcription-associated TE targeting strategies that suggest a process of convergent evolution among eukaryotic TE families. The integration of two precision-targeting elements are specifically associated with initiation of RNA Polymerase II transcription of highly expressed genes, suggesting the existence of novel mechanisms of precision TE targeting in addition to passive targeting of open chromatin. We also highlight two features that can facilitate TE survival and rapid proliferation: tissue-specific transposition and minimization of negative impacts on nearby gene function due to precision targeting.
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Affiliation(s)
- Xinyan Zhang
- Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120, China
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA
| | - Meixia Zhao
- Department of Biology, Miami University, Oxford, OH 45056, USA
| | - Donald R McCarty
- Horticultural Sciences Department, University of Florida, Gainesville, FL 32611, USA
| | - Damon Lisch
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA
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9
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Cerbin S, Wai CM, VanBuren R, Jiang N. GingerRoot: A Novel DNA Transposon Encoding Integrase-Related Transposase in Plants and Animals. Genome Biol Evol 2020; 11:3181-3193. [PMID: 31633753 PMCID: PMC6839031 DOI: 10.1093/gbe/evz230] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/20/2019] [Indexed: 02/06/2023] Open
Abstract
Transposable elements represent the largest components of many eukaryotic genomes and different genomes harbor different combinations of elements. Here, we discovered a novel DNA transposon in the genome of the clubmoss Selaginella lepidophylla. Further searching for related sequences to the conserved DDE region uncovered the presence of this superfamily of elements in fish, coral, sea anemone, and other animal species. However, this element appears restricted to Bryophytes and Lycophytes in plants. This transposon, named GingerRoot, is associated with a 6 bp (base pair) target site duplication, and 100-150 bp terminal inverted repeats. Analysis of transposase sequences identified the DDE motif, a catalytic domain, which shows similarity to the integrase of Gypsy-like long terminal repeat retrotransposons, the most abundant component in plant genomes. A total of 77 intact and several hundred truncated copies of GingerRoot elements were identified in S. lepidophylla. Like Gypsy retrotransposons, GingerRoots show a lack of insertion preference near genes, which contrasts to the compact genome size of about 100 Mb. Nevertheless, a considerable portion of GingerRoot elements was found to carry gene fragments, suggesting the capacity of duplicating gene sequences is unlikely attributed to the proximity to genes. Elements carrying gene fragments appear to be less methylated, more diverged, and more distal to genes than those without gene fragments, indicating they are preferentially retained in gene-poor regions. This study has identified a broadly dispersed, novel DNA transposon, and the first plant DNA transposon with an integrase-related transposase, suggesting the possibility of de novo formation of Gypsy-like elements in plants.
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Affiliation(s)
- Stefan Cerbin
- Department of Horticulture, Michigan State University, East Lansing, MI 48824
| | - Ching Man Wai
- Department of Horticulture, Michigan State University, East Lansing, MI 48824
| | - Robert VanBuren
- Department of Horticulture, Michigan State University, East Lansing, MI 48824
| | - Ning Jiang
- Department of Horticulture, Michigan State University, East Lansing, MI 48824
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10
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Broad RC, Bonneau JP, Beasley JT, Roden S, Philips JG, Baumann U, Hellens RP, Johnson AAT. Genome-wide identification and characterization of the GDP-L-galactose phosphorylase gene family in bread wheat. BMC PLANT BIOLOGY 2019; 19:515. [PMID: 31771507 PMCID: PMC6878703 DOI: 10.1186/s12870-019-2123-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Accepted: 11/07/2019] [Indexed: 05/26/2023]
Abstract
BACKGROUND Ascorbate is a powerful antioxidant in plants and an essential micronutrient for humans. The GDP-L-galactose phosphorylase (GGP) gene encodes the rate-limiting enzyme of the L-galactose pathway-the dominant ascorbate biosynthetic pathway in plants-and is a promising gene candidate for increasing ascorbate in crops. In addition to transcriptional regulation, GGP production is regulated at the translational level through an upstream open reading frame (uORF) in the long 5'-untranslated region (5'UTR). The GGP genes have yet to be identified in bread wheat (Triticum aestivum L.), one of the most important food grain sources for humans. RESULTS Bread wheat chromosomal groups 4 and 5 were found to each contain three homoeologous TaGGP genes on the A, B, and D subgenomes (TaGGP2-A/B/D and TaGGP1-A/B/D, respectively) and a highly conserved uORF was present in the long 5'UTR of all six genes. Phylogenetic analyses demonstrated that the TaGGP genes separate into two distinct groups and identified a duplication event of the GGP gene in the ancestor of the Brachypodium/Triticeae lineage. A microsynteny analysis revealed that the TaGGP1 and TaGGP2 subchromosomal regions have no shared synteny suggesting that TaGGP2 may have been duplicated via a transposable element. The two groups of TaGGP genes have distinct expression patterns with the TaGGP1 homoeologs broadly expressed across different tissues and developmental stages and the TaGGP2 homoeologs highly expressed in anthers. Transient transformation of the TaGGP coding sequences in Nicotiana benthamiana leaf tissue increased ascorbate concentrations more than five-fold, confirming their functional role in ascorbate biosynthesis in planta. CONCLUSIONS We have identified six TaGGP genes in the bread wheat genome, each with a highly conserved uORF. Phylogenetic and microsynteny analyses highlight that a transposable element may have been responsible for the duplication and specialized expression of GGP2 in anthers in the Brachypodium/Triticeae lineage. Transient transformation of the TaGGP coding sequences in N. benthamiana demonstrated their activity in planta. The six TaGGP genes and uORFs identified in this study provide a valuable genetic resource for increasing ascorbate concentrations in bread wheat.
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Affiliation(s)
- Ronan C Broad
- School of BioSciences, The University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - Julien P Bonneau
- School of BioSciences, The University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - Jesse T Beasley
- School of BioSciences, The University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - Sally Roden
- Centre for Tropical Crops and Biocommodities, Institute for Future Environments, Queensland University of Technology, Brisbane, Queensland, 4001, Australia
| | - Joshua G Philips
- Centre for Tropical Crops and Biocommodities, Institute for Future Environments, Queensland University of Technology, Brisbane, Queensland, 4001, Australia
| | - Ute Baumann
- School of Agriculture, The University of Adelaide, Adelaide, South Australia, 5064, Australia
| | - Roger P Hellens
- Centre for Tropical Crops and Biocommodities, Institute for Future Environments, Queensland University of Technology, Brisbane, Queensland, 4001, Australia
| | - Alexander A T Johnson
- School of BioSciences, The University of Melbourne, Melbourne, Victoria, 3010, Australia.
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Cerbin S, Jiang N. Duplication of host genes by transposable elements. Curr Opin Genet Dev 2018; 49:63-69. [PMID: 29571044 DOI: 10.1016/j.gde.2018.03.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 02/07/2018] [Accepted: 03/08/2018] [Indexed: 12/12/2022]
Abstract
The availability of large amounts of genomic and transcriptome sequences have allowed systematic surveys about the host gene sequences that have been duplicated by transposable elements. It is now clear that all super-families of transposons are capable of duplicating genes or gene fragments, and such incidents have been detected in a wide spectrum of organisms. Emerging evidence suggests that a considerable portion of them function as coding or non-coding sequences, driving innovations at molecular and phenotypic levels. Interestingly, the duplication events not only have to occur in the reproductive tissues to become heritable, but the duplicated copies are also preferentially expressed in those tissues. As a result, reproductive tissues may serve as the 'incubator' for genes generated by transposable elements.
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Affiliation(s)
- Stefan Cerbin
- Department of Horticulture, 1066 Bogue Street, Michigan State University, East Lansing, MI 48824, USA
| | - Ning Jiang
- Department of Horticulture, 1066 Bogue Street, Michigan State University, East Lansing, MI 48824, USA.
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