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Kojima KK. AcademH, a lineage of Academ DNA transposons encoding helicase found in animals and fungi. Mob DNA 2020; 11:15. [PMID: 32328173 PMCID: PMC7165386 DOI: 10.1186/s13100-020-00211-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 04/06/2020] [Indexed: 01/04/2023] Open
Abstract
Background DNA transposons are ubiquitous components of eukaryotic genomes. Academ superfamily of DNA transposons is one of the least characterized DNA transposon superfamilies in eukaryotes. DNA transposons belonging to the Academ superfamily have been reported from various animals, one red algal species Chondrus crispus, and one fungal species Puccinia graminis. Six Academ families from P. graminis encode a helicase in addition to putative transposase, while some other families encode a single protein which contains a putative transposase and an XPG nuclease. Results Systematic searches on Repbase and BLAST searches against publicly available genome sequences revealed that several species of fungi and animals contain multiple Academ transposon families encoding a helicase. These AcademH families generate 9 or 10-bp target site duplications (TSDs) while Academ families lacking helicase generate 3 or 4-bp TSDs. Phylogenetic analysis clearly shows two lineages inside of Academ, designated here as AcademH and AcademX for encoding helicase or XPG nuclease, respectively. One sublineage of AcademH in animals encodes plant homeodomain (PHD) finger in its transposase, and its remnants are found in several fish genomes. Conclusions The AcademH lineage of TEs is widely distributed in animals and fungi, and originated early in the evolution of Academ DNA transposons. This analysis highlights the structural diversity in one less studied superfamily of eukaryotic DNA transposons.
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Affiliation(s)
- Kenji K Kojima
- Genetic Information Research Institute, Cupertino, CA 95014 USA
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2
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Hou F, Ma B, Xin Y, Kuang L, He N. Horizontal transfers of LTR retrotransposons in seven species of Rosales. Genome 2018; 61:587-594. [PMID: 29958091 DOI: 10.1139/gen-2017-0208] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Horizontal transposable element transfer (HTT) events have occurred among a large number of species and play important roles in the composition and evolution of eukaryotic genomes. HTTs are also regarded as effective forces in promoting genomic variation and biological innovation. In the present study, HTT events were identified and analyzed in seven sequenced species of Rosales using bioinformatics methods by comparing sequence conservation and Ka/Ks value of reverse transcriptase (RT) with 20 conserved genes, estimating the dating of HTTs, and analyzing the phylogenetic relationships. Seven HTT events involving long terminal repeat (LTR) retrotransposons, two HTTs between Morus notabilis and Ziziphus jujuba, and five between Malus domestica and Pyrus bretschneideri were identified. Further analysis revealed that these LTR retrotransposons had functional structures, and the copy insertion times were lower than the dating of HTTs, particularly in Mn.Zj.1 and Md.Pb.3. Altogether, the results demonstrate that LTR retrotransposons still have potential transposition activity in host genomes. These results indicate that HTT events are another strategy for exchanging genetic material among species and are important for the evolution of genomes.
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Affiliation(s)
- Fei Hou
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Beibei, Chongqing 400715, China.,State Key Laboratory of Silkworm Genome Biology, Southwest University, Beibei, Chongqing 400715, China
| | - Bi Ma
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Beibei, Chongqing 400715, China.,State Key Laboratory of Silkworm Genome Biology, Southwest University, Beibei, Chongqing 400715, China
| | - Youchao Xin
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Beibei, Chongqing 400715, China.,State Key Laboratory of Silkworm Genome Biology, Southwest University, Beibei, Chongqing 400715, China
| | - Lulu Kuang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Beibei, Chongqing 400715, China.,State Key Laboratory of Silkworm Genome Biology, Southwest University, Beibei, Chongqing 400715, China
| | - Ningjia He
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Beibei, Chongqing 400715, China.,State Key Laboratory of Silkworm Genome Biology, Southwest University, Beibei, Chongqing 400715, China
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3
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Horizontal acquisition of transposable elements and viral sequences: patterns and consequences. Curr Opin Genet Dev 2018; 49:15-24. [PMID: 29505963 DOI: 10.1016/j.gde.2018.02.007] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 02/13/2018] [Accepted: 02/14/2018] [Indexed: 12/30/2022]
Abstract
It is becoming clear that most eukaryotic transposable elements (TEs) owe their evolutionary success in part to horizontal transfer events, which enable them to invade new species. Recent large-scale studies are beginning to unravel the mechanisms and ecological factors underlying this mode of transmission. Viruses are increasingly recognized as vectors in the process but also as a direct source of genetic material horizontally acquired by eukaryotic organisms. Because TEs and endogenous viruses are major catalysts of variation and innovation in genomes, we argue that horizontal inheritance has had a more profound impact in eukaryotic evolution than is commonly appreciated. To support this proposal, we compile a list of examples, including some previously unrecognized, whereby new host functions and phenotypes can be directly attributed to horizontally acquired TE or viral sequences. We predict that the number of examples will rapidly grow in the future as the prevalence of horizontal transfer in the life cycle of TEs becomes even more apparent, firmly establishing this form of non-Mendelian inheritance as a consequential facet of eukaryotic evolution.
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Wallau GL, Vieira C, Loreto ÉLS. Genetic exchange in eukaryotes through horizontal transfer: connected by the mobilome. Mob DNA 2018; 9:6. [PMID: 29422954 PMCID: PMC5791352 DOI: 10.1186/s13100-018-0112-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 01/24/2018] [Indexed: 12/11/2022] Open
Abstract
Background All living species contain genetic information that was once shared by their common ancestor. DNA is being inherited through generations by vertical transmission (VT) from parents to offspring and from ancestor to descendant species. This process was considered the sole pathway by which biological entities exchange inheritable information. However, Horizontal Transfer (HT), the exchange of genetic information by other means than parents to offspring, was discovered in prokaryotes along with strong evidence showing that it is a very important process by which prokaryotes acquire new genes. Main body For some time now, it has been a scientific consensus that HT events were rare and non-relevant for evolution of eukaryotic species, but there is growing evidence supporting that HT is an important and frequent phenomenon in eukaryotes as well. Conclusion Here, we will discuss the latest findings regarding HT among eukaryotes, mainly HT of transposons (HTT), establishing HTT once and for all as an important phenomenon that should be taken into consideration to fully understand eukaryotes genome evolution. In addition, we will discuss the latest development methods to detect such events in a broader scale and highlight the new approaches which should be pursued by researchers to fill the knowledge gaps regarding HTT among eukaryotes.
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Affiliation(s)
- Gabriel Luz Wallau
- 1Entomology Department, Aggeu Magalhães Institute, Oswaldo Cruz Foundation, Recife, PE Brazil
| | - Cristina Vieira
- 2Université de Lyon, Université Lyon 1, CNRS, Laboratoire de Biométrie et Biologie Evolutive, UMR5558, F-69622 Villeurbanne, France
| | - Élgion Lúcio Silva Loreto
- 3Department of Biochemistry and Molecular Biology, Federal University of Santa Maria, Santa Maria, RS Brazil
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Heringer P, Dias GB, Kuhn GCS. A Horizontally Transferred Autonomous Helitron Became a Full Polydnavirus Segment in Cotesia vestalis. G3 (BETHESDA, MD.) 2017; 7:3925-3935. [PMID: 29042411 PMCID: PMC5714489 DOI: 10.1534/g3.117.300280] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 10/11/2017] [Indexed: 12/17/2022]
Abstract
Bracoviruses associate symbiotically with thousands of parasitoid wasp species in the family Braconidae, working as virulence gene vectors, and allowing the development of wasp larvae within hosts. These viruses are composed of multiple DNA circles that are packaged into infective particles, and injected together with wasp's eggs during parasitization. One of the viral segments of Cotesia vestalis bracovirus contains a gene that has been previously described as a helicase of unknown origin. Here, we demonstrate that this gene is a Rep/Helicase from an intact Helitron transposable element that covers the viral segment almost entirely. We also provide evidence that this element underwent at least two horizontal transfers, which appear to have occurred consecutively: first from a Drosophila host ancestor to the genome of the parasitoid wasp C. vestalis and its bracovirus, and then from C. vestalis to a lepidopteran host (Bombyx mori). Our results reinforce the idea of parasitoid wasps as frequent agents of horizontal transfers in eukaryotes. Additionally, this Helitron-bracovirus segment is the first example of a transposable element that effectively became a whole viral circle.
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Affiliation(s)
- Pedro Heringer
- Departamento de Biologia Geral, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil
| | - Guilherme B Dias
- Departamento de Biologia Geral, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil
| | - Gustavo C S Kuhn
- Departamento de Biologia Geral, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil
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Drezen JM, Josse T, Bézier A, Gauthier J, Huguet E, Herniou EA. Impact of Lateral Transfers on the Genomes of Lepidoptera. Genes (Basel) 2017; 8:E315. [PMID: 29120392 PMCID: PMC5704228 DOI: 10.3390/genes8110315] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2017] [Revised: 10/31/2017] [Accepted: 11/01/2017] [Indexed: 11/25/2022] Open
Abstract
Transfer of DNA sequences between species regardless of their evolutionary distance is very common in bacteria, but evidence that horizontal gene transfer (HGT) also occurs in multicellular organisms has been accumulating in the past few years. The actual extent of this phenomenon is underestimated due to frequent sequence filtering of "alien" DNA before genome assembly. However, recent studies based on genome sequencing have revealed, and experimentally verified, the presence of foreign DNA sequences in the genetic material of several species of Lepidoptera. Large DNA viruses, such as baculoviruses and the symbiotic viruses of parasitic wasps (bracoviruses), have the potential to mediate these transfers in Lepidoptera. In particular, using ultra-deep sequencing, newly integrated transposons have been identified within baculovirus genomes. Bacterial genes have also been acquired by genomes of Lepidoptera, as in other insects and nematodes. In addition, insertions of bracovirus sequences were present in the genomes of certain moth and butterfly lineages, that were likely corresponding to rearrangements of ancient integrations. The viral genes present in these sequences, sometimes of hymenopteran origin, have been co-opted by lepidopteran species to confer some protection against pathogens.
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Affiliation(s)
- Jean-Michel Drezen
- Institut de Recherche sur la Biologie de l'Insecte, UMR CNRS 7261, UFR des Sciences et Techniques, Université de Tours-François Rabelais, 37200 Tours, France.
| | - Thibaut Josse
- Institut de Recherche sur la Biologie de l'Insecte, UMR CNRS 7261, UFR des Sciences et Techniques, Université de Tours-François Rabelais, 37200 Tours, France.
| | - Annie Bézier
- Institut de Recherche sur la Biologie de l'Insecte, UMR CNRS 7261, UFR des Sciences et Techniques, Université de Tours-François Rabelais, 37200 Tours, France.
| | - Jérémy Gauthier
- Institut de Recherche sur la Biologie de l'Insecte, UMR CNRS 7261, UFR des Sciences et Techniques, Université de Tours-François Rabelais, 37200 Tours, France.
| | - Elisabeth Huguet
- Institut de Recherche sur la Biologie de l'Insecte, UMR CNRS 7261, UFR des Sciences et Techniques, Université de Tours-François Rabelais, 37200 Tours, France.
| | - Elisabeth Anne Herniou
- Institut de Recherche sur la Biologie de l'Insecte, UMR CNRS 7261, UFR des Sciences et Techniques, Université de Tours-François Rabelais, 37200 Tours, France.
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