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Cagliani R, Forni D, Mozzi A, Fuchs R, Tussia-Cohen D, Arrigoni F, Pozzoli U, De Gioia L, Hagai T, Sironi M. Evolution of Virus-like Features and Intrinsically Disordered Regions in Retrotransposon-derived Mammalian Genes. Mol Biol Evol 2024; 41:msae154. [PMID: 39101471 PMCID: PMC11299033 DOI: 10.1093/molbev/msae154] [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: 05/29/2024] [Revised: 07/16/2024] [Accepted: 07/19/2024] [Indexed: 08/06/2024] Open
Abstract
Several mammalian genes have originated from the domestication of retrotransposons, selfish mobile elements related to retroviruses. Some of the proteins encoded by these genes have maintained virus-like features; including self-processing, capsid structure formation, and the generation of different isoforms through -1 programmed ribosomal frameshifting. Using quantitative approaches in molecular evolution and biophysical analyses, we studied 28 retrotransposon-derived genes, with a focus on the evolution of virus-like features. By analyzing the rate of synonymous substitutions, we show that the -1 programmed ribosomal frameshifting mechanism in three of these genes (PEG10, PNMA3, and PNMA5) is conserved across mammals and originates alternative proteins. These genes were targets of positive selection in primates, and one of the positively selected sites affects a B-cell epitope on the spike domain of the PNMA5 capsid, a finding reminiscent of observations in infectious viruses. More generally, we found that retrotransposon-derived proteins vary in their intrinsically disordered region content and this is directly associated with their evolutionary rates. Most positively selected sites in these proteins are located in intrinsically disordered regions and some of them impact protein posttranslational modifications, such as autocleavage and phosphorylation. Detailed analyses of the biophysical properties of intrinsically disordered regions showed that positive selection preferentially targeted regions with lower conformational entropy. Furthermore, positive selection introduces variation in binary sequence patterns across orthologues, as well as in chain compaction. Our results shed light on the evolutionary trajectories of a unique class of mammalian genes and suggest a novel approach to study how intrinsically disordered region biophysical characteristics are affected by evolution.
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Affiliation(s)
- Rachele Cagliani
- Scientific Institute IRCCS E. MEDEA, Computational Biology Unit, Bosisio Parini 23842, Italy
| | - Diego Forni
- Scientific Institute IRCCS E. MEDEA, Computational Biology Unit, Bosisio Parini 23842, Italy
| | - Alessandra Mozzi
- Scientific Institute IRCCS E. MEDEA, Computational Biology Unit, Bosisio Parini 23842, Italy
| | - Rotem Fuchs
- Shmunis School of Biomedicine and Cancer Research, George S Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Dafna Tussia-Cohen
- Shmunis School of Biomedicine and Cancer Research, George S Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Federica Arrigoni
- Department of Biotechnology and Biosciences, University of Milan-Bicocca, Milan 20126, Italy
| | - Uberto Pozzoli
- Scientific Institute IRCCS E. MEDEA, Computational Biology Unit, Bosisio Parini 23842, Italy
| | - Luca De Gioia
- Department of Biotechnology and Biosciences, University of Milan-Bicocca, Milan 20126, Italy
| | - Tzachi Hagai
- Shmunis School of Biomedicine and Cancer Research, George S Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Manuela Sironi
- Scientific Institute IRCCS E. MEDEA, Computational Biology Unit, Bosisio Parini 23842, Italy
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Chang NC, Wells JN, Wang AY, Schofield P, Huang YC, Truong VH, Simoes-Costa M, Feschotte C. Gag proteins encoded by endogenous retroviruses are required for zebrafish development. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.25.586437. [PMID: 38585793 PMCID: PMC10996621 DOI: 10.1101/2024.03.25.586437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Transposable elements (TEs) make up the bulk of eukaryotic genomes and examples abound of TE-derived sequences repurposed for organismal function. The process by which TEs become coopted remains obscure because most cases involve ancient, transpositionally inactive elements. Reports of active TEs serving beneficial functions are scarce and often contentious due to difficulties in manipulating repetitive sequences. Here we show that recently active TEs in zebrafish encode products critical for embryonic development. Knockdown and rescue experiments demonstrate that the endogenous retrovirus family BHIKHARI-1 (Bik-1) encodes a Gag protein essential for mesoderm development. Mechanistically, Bik-1 Gag associates with the cell membrane and its ectopic expression in chicken embryos alters cell migration. Similarly, depletion of BHIKHARI-2 Gag, a relative of Bik-1, causes defects in neural crest development in zebrafish. We propose an "addiction" model to explain how active TEs can be integrated into conserved developmental processes.
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Affiliation(s)
- Ni-Chen Chang
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14850, USA
| | - Jonathan N Wells
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14850, USA
| | - Andrew Y Wang
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14850, USA
| | - Phillip Schofield
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14850, USA
| | - Yi-Chia Huang
- Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
- Department of Pathology, Boston Children's Hospital, Boston, MA 02115, USA
| | - Vinh H Truong
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14850, USA
| | - Marcos Simoes-Costa
- Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
- Department of Pathology, Boston Children's Hospital, Boston, MA 02115, USA
| | - Cédric Feschotte
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14850, USA
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3
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Garcia S, Kovarik A, Maiwald S, Mann L, Schmidt N, Pascual-Díaz JP, Vitales D, Weber B, Heitkam T. The Dynamic Interplay Between Ribosomal DNA and Transposable Elements: A Perspective From Genomics and Cytogenetics. Mol Biol Evol 2024; 41:msae025. [PMID: 38306580 PMCID: PMC10946416 DOI: 10.1093/molbev/msae025] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 12/06/2023] [Accepted: 01/29/2024] [Indexed: 02/04/2024] Open
Abstract
Although both are salient features of genomes, at first glance ribosomal DNAs and transposable elements are genetic elements with not much in common: whereas ribosomal DNAs are mainly viewed as housekeeping genes that uphold all prime genome functions, transposable elements are generally portrayed as selfish and disruptive. These opposing characteristics are also mirrored in other attributes: organization in tandem (ribosomal DNAs) versus organization in a dispersed manner (transposable elements); evolution in a concerted manner (ribosomal DNAs) versus evolution by diversification (transposable elements); and activity that prolongs genomic stability (ribosomal DNAs) versus activity that shortens it (transposable elements). Re-visiting relevant instances in which ribosomal DNA-transposable element interactions have been reported, we note that both repeat types share at least four structural and functional hallmarks: (1) they are repetitive DNAs that shape genomes in evolutionary timescales, (2) they exchange structural motifs and can enter co-evolution processes, (3) they are tightly controlled genomic stress sensors playing key roles in senescence/aging, and (4) they share common epigenetic marks such as DNA methylation and histone modification. Here, we give an overview of the structural, functional, and evolutionary characteristics of both ribosomal DNAs and transposable elements, discuss their roles and interactions, and highlight trends and future directions as we move forward in understanding ribosomal DNA-transposable element associations.
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Affiliation(s)
- Sònia Garcia
- Institut Botànic de Barcelona (IBB), CSIC-CMCNB, 08038 Barcelona, Catalonia, Spain
| | - Ales Kovarik
- Institute of Biophysics, Academy of Sciences of the Czech Republic, 61265 Brno, Czech Republic
| | - Sophie Maiwald
- Faculty of Biology, Technische Universität Dresden, D-01069 Dresden, Germany
| | - Ludwig Mann
- Faculty of Biology, Technische Universität Dresden, D-01069 Dresden, Germany
| | - Nicola Schmidt
- Faculty of Biology, Technische Universität Dresden, D-01069 Dresden, Germany
| | | | - Daniel Vitales
- Institut Botànic de Barcelona (IBB), CSIC-CMCNB, 08038 Barcelona, Catalonia, Spain
- Laboratori de Botànica–Unitat Associada CSIC, Facultat de Farmàcia i Ciències de l’Alimentació, Universitat de Barcelona, 08028 Barcelona, Catalonia, Spain
| | - Beatrice Weber
- Faculty of Biology, Technische Universität Dresden, D-01069 Dresden, Germany
| | - Tony Heitkam
- Faculty of Biology, Technische Universität Dresden, D-01069 Dresden, Germany
- Institute of Biology, NAWI Graz, Karl-Franzens-Universität, A-8010 Graz, Austria
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4
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Maiwald S, Mann L, Garcia S, Heitkam T. Evolving Together: Cassandra Retrotransposons Gradually Mirror Promoter Mutations of the 5S rRNA Genes. Mol Biol Evol 2024; 41:msae010. [PMID: 38262464 PMCID: PMC10853983 DOI: 10.1093/molbev/msae010] [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: 07/21/2023] [Revised: 10/26/2023] [Accepted: 12/11/2023] [Indexed: 01/25/2024] Open
Abstract
The 5S rRNA genes are among the most conserved nucleotide sequences across all species. Similar to the 5S preservation we observe the occurrence of 5S-related nonautonomous retrotransposons, so-called Cassandras. Cassandras harbor highly conserved 5S rDNA-related sequences within their long terminal repeats, advantageously providing them with the 5S internal promoter. However, the dynamics of Cassandra retrotransposon evolution in the context of 5S rRNA gene sequence information and structural arrangement are still unclear, especially: (1) do we observe repeated or gradual domestication of the highly conserved 5S promoter by Cassandras and (2) do changes in 5S organization such as in the linked 35S-5S rDNA arrangements impact Cassandra evolution? Here, we show evidence for gradual co-evolution of Cassandra sequences with their corresponding 5S rDNAs. To follow the impact of 5S rDNA variability on Cassandra TEs, we investigate the Asteraceae family where highly variable 5S rDNAs, including 5S promoter shifts and both linked and separated 35S-5S rDNA arrangements have been reported. Cassandras within the Asteraceae mirror 5S rDNA promoter mutations of their host genome, likely as an adaptation to the host's specific 5S transcription factors and hence compensating for evolutionary changes in the 5S rDNA sequence. Changes in the 5S rDNA sequence and in Cassandras seem uncorrelated with linked/separated rDNA arrangements. We place all these observations into the context of angiosperm 5S rDNA-Cassandra evolution, discuss Cassandra's origin hypotheses (single or multiple) and Cassandra's possible impact on rDNA and plant genome organization, giving new insights into the interplay of ribosomal genes and transposable elements.
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Affiliation(s)
- Sophie Maiwald
- Faculty of Biology, Technische Universität Dresden, 01069 Dresden, Germany
| | - Ludwig Mann
- Faculty of Biology, Technische Universität Dresden, 01069 Dresden, Germany
| | - Sònia Garcia
- Institut Botànic de Barcelona, IBB (CSIC-MCNB), 08038 Barcelona, Catalonia, Spain
| | - Tony Heitkam
- Faculty of Biology, Technische Universität Dresden, 01069 Dresden, Germany
- Institute of Biology, NAWI Graz, Karl-Franzens-Universität, 8010 Graz, Austria
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Oggenfuss U, Badet T, Croll D. A systematic screen for co-option of transposable elements across the fungal kingdom. Mob DNA 2024; 15:2. [PMID: 38245743 PMCID: PMC10799480 DOI: 10.1186/s13100-024-00312-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Accepted: 01/04/2024] [Indexed: 01/22/2024] Open
Abstract
How novel protein functions are acquired is a central question in molecular biology. Key paths to novelty include gene duplications, recombination or horizontal acquisition. Transposable elements (TEs) are increasingly recognized as a major source of novel domain-encoding sequences. However, the impact of TE coding sequences on the evolution of the proteome remains understudied. Here, we analyzed 1237 genomes spanning the phylogenetic breadth of the fungal kingdom. We scanned proteomes for evidence of co-occurrence of TE-derived domains along with other conventional protein functional domains. We detected more than 13,000 predicted proteins containing potentially TE-derived domain, of which 825 were identified in more than five genomes, indicating that many host-TE fusions may have persisted over long evolutionary time scales. We used the phylogenetic context to identify the origin and retention of individual TE-derived domains. The most common TE-derived domains are helicases derived from Academ, Kolobok or Helitron. We found putative TE co-options at a higher rate in genomes of the Saccharomycotina, providing an unexpected source of protein novelty in these generally TE depleted genomes. We investigated in detail a candidate host-TE fusion with a heterochromatic transcriptional silencing function that may play a role in TE and gene regulation in ascomycetes. The affected gene underwent multiple full or partial losses within the phylum. Overall, our work establishes a kingdom-wide view of putative host-TE fusions and facilitates systematic investigations of candidate fusion proteins.
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Affiliation(s)
- Ursula Oggenfuss
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, CH-2000, Neuchâtel, Switzerland
- Department of Microbiology and Immunology, University of Minnesota, Medical School, Minneapolis, Minnesota, United States of America
| | - Thomas Badet
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, CH-2000, Neuchâtel, Switzerland
| | - Daniel Croll
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, CH-2000, Neuchâtel, Switzerland.
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Kirov I, Merkulov P, Polkhovskaya E, Konstantinov Z, Kazancev M, Saenko K, Polkhovskiy A, Dudnikov M, Garibyan T, Demurin Y, Soloviev A. Epigenetic Stress and Long-Read cDNA Sequencing of Sunflower ( Helianthus annuus L.) Revealed the Origin of the Plant Retrotranscriptome. PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11243579. [PMID: 36559691 PMCID: PMC9784723 DOI: 10.3390/plants11243579] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 12/13/2022] [Accepted: 12/13/2022] [Indexed: 06/12/2023]
Abstract
Transposable elements (TEs) contribute not only to genome diversity but also to transcriptome diversity in plants. To unravel the sources of LTR retrotransposon (RTE) transcripts in sunflower, we exploited a recently developed transposon activation method ('TEgenesis') along with long-read cDNA Nanopore sequencing. This approach allows for the identification of 56 RTE transcripts from different genomic loci including full-length and non-autonomous RTEs. Using the mobilome analysis, we provided a new set of expressed and transpositional active sunflower RTEs for future studies. Among them, a Ty3/Gypsy RTE called SUNTY3 exhibited ongoing transposition activity, as detected by eccDNA analysis. We showed that the sunflower genome contains a diverse set of non-autonomous RTEs encoding a single RTE protein, including the previously described TR-GAG (terminal repeat with the GAG domain) as well as new categories, TR-RT-RH, TR-RH, and TR-INT-RT. Our results demonstrate that 40% of the loci for RTE-related transcripts (nonLTR-RTEs) lack their LTR sequences and resemble conventional eucaryotic genes encoding RTE-related proteins with unknown functions. It was evident based on phylogenetic analysis that three nonLTR-RTEs encode GAG (HadGAG1-3) fused to a host protein. These HadGAG proteins have homologs found in other plant species, potentially indicating GAG domestication. Ultimately, we found that the sunflower retrotranscriptome originated from the transcription of active RTEs, non-autonomous RTEs, and gene-like RTE transcripts, including those encoding domesticated proteins.
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Affiliation(s)
- Ilya Kirov
- All-Russia Research Institute of Agricultural Biotechnology, Timiryazevskaya Str. 42, 127550 Moscow, Russia
- Moscow Institute of Physics and Technology, 141701 Dolgoprudny, Russia
| | - Pavel Merkulov
- All-Russia Research Institute of Agricultural Biotechnology, Timiryazevskaya Str. 42, 127550 Moscow, Russia
- Moscow Institute of Physics and Technology, 141701 Dolgoprudny, Russia
| | - Ekaterina Polkhovskaya
- All-Russia Research Institute of Agricultural Biotechnology, Timiryazevskaya Str. 42, 127550 Moscow, Russia
| | - Zakhar Konstantinov
- All-Russia Research Institute of Agricultural Biotechnology, Timiryazevskaya Str. 42, 127550 Moscow, Russia
| | - Mikhail Kazancev
- All-Russia Research Institute of Agricultural Biotechnology, Timiryazevskaya Str. 42, 127550 Moscow, Russia
- Moscow Institute of Physics and Technology, 141701 Dolgoprudny, Russia
| | - Ksenia Saenko
- All-Russia Research Institute of Agricultural Biotechnology, Timiryazevskaya Str. 42, 127550 Moscow, Russia
- Federal Research Center of Biological Plant Protection, 350039 Krasnodar, Russia
| | - Alexander Polkhovskiy
- All-Russia Research Institute of Agricultural Biotechnology, Timiryazevskaya Str. 42, 127550 Moscow, Russia
- Moscow Institute of Physics and Technology, 141701 Dolgoprudny, Russia
- Skolkovo Institute of Science and Technology, 121205 Moscow, Russia
| | - Maxim Dudnikov
- All-Russia Research Institute of Agricultural Biotechnology, Timiryazevskaya Str. 42, 127550 Moscow, Russia
- Moscow Institute of Physics and Technology, 141701 Dolgoprudny, Russia
| | - Tsovinar Garibyan
- All-Russia Research Institute of Agricultural Biotechnology, Timiryazevskaya Str. 42, 127550 Moscow, Russia
| | - Yakov Demurin
- Pustovoit All-Russia Research Institute of Oilseed Crops, Filatova St. 17, 350038 Krasnodar, Russia
| | - Alexander Soloviev
- All-Russia Research Institute of Agricultural Biotechnology, Timiryazevskaya Str. 42, 127550 Moscow, Russia
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A Genome-Wide Search for Candidate Genes of Meat Production in Jalgin Merino Considering Known Productivity Genes. Genes (Basel) 2022; 13:genes13081337. [PMID: 35893074 PMCID: PMC9331477 DOI: 10.3390/genes13081337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 07/23/2022] [Accepted: 07/24/2022] [Indexed: 11/17/2022] Open
Abstract
In a group of Jalgin merino rams with no significant influence on the dispersion of the phenotypes of known productivity genes (MSTN, MEF2B, FABP4, etc.), a genome-wide search for associations of individual polymorphisms with intravital indicators of meat productivity was performed. Using the Ovine Infinium HD BeadChip 600K, 606,000 genome loci were evaluated. Twenty-three substitutions were found to be significantly associated with external measurements of the body and ultrasonic parameters. This made it possible to describe 14 candidate genes, the structural features of which can cause changes in animal phenotypes. No closely spaced genes were found for two substitutions. The identified polymorphisms were found in the exons, introns, and adjacent regions of the following genes and transcripts: CDCA2, ENSOARG00000014477, C4BPA, RIPOR2, ENSOARG00000007198, ENSOARG00000026965 (LincRNA), ENSOARG00000026436 (LincRNA), ENSOARG00000026782 (LincRNA), TENM3, RTL8A, MOSPD1, RTL8С, RIMS2, and P4HA3. The detected genes affect the metabolic pathways of cell differentiation and proliferation and are associated with the regulation of the immune system. This confirms their possible participation in the formation of the phenotypes of productivity parameters in animals and indicates the need for further study of the structure of candidate genes in order to identify their internal polymorphisms.
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Zheng J, Wei Y, Han GZ. The diversity and evolution of retroviruses: perspectives from viral “fossils”. Virol Sin 2022; 37:11-18. [PMID: 35234634 PMCID: PMC8922424 DOI: 10.1016/j.virs.2022.01.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 10/12/2021] [Indexed: 01/19/2023] Open
Abstract
Retroviruses exclusively infect vertebrates, causing a variety of diseases. The replication of retroviruses requires reverse transcription and integration into host genomes. When infecting germline cells, retroviruses become inherited vertically, forming endogenous retroviruses (ERVs). ERVs document past viral infections, providing molecular fossils for studying the evolutionary history of retroviruses. In this review, we summarize the recent advances in understanding the diversity and evolution of retroviruses from the perspectives of viral fossils, and discuss the effects of ERVs on the evolution of host biology. Recent advances in understanding the diversity and evolution of retroviruses. Methods to analyze ERVs. The effects of ERVs on the evolution of host biology.
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Affiliation(s)
- Jialu Zheng
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
| | - Yutong Wei
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
| | - Guan-Zhu Han
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China.
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Taming, Domestication and Exaptation: Trajectories of Transposable Elements in Genomes. Cells 2021; 10:cells10123590. [PMID: 34944100 PMCID: PMC8700633 DOI: 10.3390/cells10123590] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 11/30/2021] [Accepted: 12/06/2021] [Indexed: 02/06/2023] Open
Abstract
During evolution, several types of sequences pass through genomes. Along with mutations and internal genetic tinkering, they are a useful source of genetic variability for adaptation and evolution. Most of these sequences are acquired by horizontal transfers (HT), but some of them may come from the genomes themselves. If they are not lost or eliminated quickly, they can be tamed, domesticated, or even exapted. Each of these processes results from a series of events, depending on the interactions between these sequences and the host genomes, but also on environmental constraints, through their impact on individuals or population fitness. After a brief reminder of the characteristics of each of these states (taming, domestication, exaptation), the evolutionary trajectories of these new or acquired sequences will be presented and discussed, emphasizing that they are not totally independent insofar as the first can constitute a step towards the second, and the second is another step towards the third.
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Wang Y, Wang Q, Wu Z, Han GZ. Segregating Complete Tf2 Elements Are Largely Neutral in Fission Yeast. Genome Biol Evol 2021; 13:6430117. [PMID: 34791222 PMCID: PMC8634392 DOI: 10.1093/gbe/evab254] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/10/2021] [Indexed: 11/14/2022] Open
Abstract
Transposable elements (TEs) comprise a large proportion of the eukaryote genomes. Yet it remains poorly understood how TEs influence the fitness of the hosts carrying them. Here, we empirically test the impact of TEs on the host fitness in the fission yeast Schizosaccharomyces pombe. We find that two families of TEs (Tf1 and Tf2 elements), both of which belong to long terminal repeat retrotransposons, are highly polymorphic among individual S. pombe strains. Only 13 complete Tf2 elements are identified in S. pombe laboratory strain 972. These 13 Tf2 elements integrated into host genomes in very recent time and are segregating within the S. pombe population. Through knocking out each of the 13 Tf2 elements in S. pombe strain 972, we find Tf2 knockout does not affect the host fitness, and Tf2 elements do not alter the expression of nearby genes. Challenged by diverse forms of stress, the Tf2 knockout strains do not exhibit different growth rates from wild-type strain. Together, we conclude that segregating complete Tf2 elements insertions are largely neutral to host fitness in the fission yeast. Our study provides genome-wide empirical support for the selfish nature of TEs in fission yeast.
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Affiliation(s)
- Yan Wang
- College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Qin Wang
- College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Zhiwei Wu
- College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Guan-Zhu Han
- College of Life Sciences, Nanjing Normal University, Nanjing, China
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