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Miyao A, Yamanouchi U. Transposable element finder (TEF): finding active transposable elements from next generation sequencing data. BMC Bioinformatics 2022; 23:500. [PMID: 36418944 PMCID: PMC9682801 DOI: 10.1186/s12859-022-05011-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 10/26/2022] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Detection of newly transposed events by transposable elements (TEs) from next generation sequence (NGS) data is difficult, due to their multiple distribution sites over the genome containing older TEs. The previously reported Transposon Insertion Finder (TIF) detects TE transpositions on the reference genome from NGS short reads using end sequences of target TE. TIF requires the sequence of target TE and is not able to detect transpositions for TEs with an unknown sequence. RESULT The new algorithm Transposable Element Finder (TEF) enables the detection of TE transpositions, even for TEs with an unknown sequence. TEF is a finding tool of transposed TEs, in contrast to TIF as a detection tool of transposed sites for TEs with a known sequence. The transposition event is often accompanied with a target site duplication (TSD). Focusing on TSD, two algorithms to detect both ends of TE, TSDs and target sites are reported here. One is based on the grouping with TSDs and direct comparison of k-mers from NGS without similarity search. The other is based on the junction mapping of TE end sequence candidates. Both methods succeed to detect both ends and TSDs of known active TEs in several tests with rice, Arabidopsis and Drosophila data and discover several new TEs in new locations. PCR confirmed the detected transpositions of TEs in several test cases in rice. CONCLUSIONS TEF detects transposed TEs with TSDs as a result of TE transposition, sequences of both ends and their inserted positions of transposed TEs by direct comparison of NGS data between two samples. Genotypes of transpositions are verified by counting of junctions of head and tail, and non-insertion sequences in NGS reads. TEF is easy to run and independent of any TE library, which makes it useful to detect insertions from unknown TEs bypassed by common TE annotation pipelines.
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Affiliation(s)
- Akio Miyao
- grid.416835.d0000 0001 2222 0432Institute of Crop Science, National Agriculture and Food Research Organization, 2-1-2, Kannondai, Tsukuba, Ibaraki 305-8518 Japan
| | - Utako Yamanouchi
- grid.416835.d0000 0001 2222 0432Institute of Crop Science, National Agriculture and Food Research Organization, 2-1-2, Kannondai, Tsukuba, Ibaraki 305-8518 Japan
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2
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Yushkova E. Contribution of transposable elements to transgenerational effects of chronic radioactive exposure of natural populations of Drosophila melanogaster living for a long time in the zone of the Chernobyl nuclear disaster. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2022; 251-252:106945. [PMID: 35696883 DOI: 10.1016/j.jenvrad.2022.106945] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 05/17/2022] [Accepted: 06/06/2022] [Indexed: 06/15/2023]
Abstract
The accident at the Chernobyl Nuclear Power Plant (ChNPP) led to the negative impact of chronic radioactive contamination on populations of organisms associated with the transgenerational transmission of genome instability. When the destabilization of genome, different genetic damages occur, the accumulation of which leads to the formation of mutations, morphological anomalies, and mortality in the offspring. The mechanisms underlying the manifestation of transgenerational events in the offspring of irradiated parents are not well understood. In this study, for the first time, the features of the influence of transposable elements (TEs) on the long-term biological consequences of the ChNPP are considered. In this work, specimens of D. melanogaster obtained from natural populations in 2007 in the areas of the ChNPP with heterogeneous radioactive contamination were studied. The descendants from these populations were maintained in laboratory (inbred) conditions for 160 generations. A stable transgenerational transmission of dominant lethal mutations (DLMs) to the offspring of all studied populations was shown. The DLM frequencies strongly were correlated with the level of survival of offspring. The mean frequencies of recessive sex-linked lethal mutations varied at the level of spontaneous point mutations. The simultaneous presence of P, hobo and I elements indicates that the studied populations do not have a definite cytotype, their phenotypic status is unstable. The behavior of TEs in the genomes of offspring depends not only on parental exposure, but also on origin of population, distance to the ChNPP, and inbred conditions. The obtained results confirm the hypothesis that TEs are involved in transgenerational transmission and accumulation of mutations by the offspring of irradiated parents. The TEs pattern present in the Chernobyl genomes of D. melanogaster is a peculiar of epigenetic mechanism for the regulation of plasticity and adaptation of populations living for many generations under conditions of a technogenically caused radiation background.
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Affiliation(s)
- Elena Yushkova
- Institute of Biology of Komi Scientific Centre of the Ural Branch of the Russian Academy of Science, Syktyvkar, Russia.
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3
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Bertocchi NÁ, Oliveira TDD, Deprá M, Goñi B, Valente VLS. Interpopulation variation of transposable elements of the hAT superfamily in Drosophila willistoni (Diptera: Drosophilidae): in-situ approach. Genet Mol Biol 2022; 45:e20210287. [PMID: 35297941 PMCID: PMC8961557 DOI: 10.1590/1678-4685-gmb-2021-0287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 01/31/2022] [Indexed: 11/22/2022] Open
Abstract
Transposable elements are abundant and dynamic part of the genome, influencing
organisms in different ways through their presence or mobilization, or by acting
directly on pre- and post-transcriptional regulatory regions. We compared and
evaluated the presence, structure, and copy number of three hAT
superfamily transposons (hobo, BuT2, and mar)
in five strains of Drosophila willistoni
species. These D. willistoni strains are
of different geographical origins, sampled across the north-south occurrence of
this species. We used sequenced clones of the hAT elements in
fluorescence in-situ hybridizations in the polytene chromosomes
of three strains of D. willistoni. We also analyzed the
structural characteristics and number of copies of these hAT
elements in the 10 currently available sequenced genomes of the
willistoni group. We found that hobo,
BuT2, and mar were widely distributed in
D. willistoni polytene chromosomes and sequenced genomes of
the willistoni group, except for mar, which is
restricted to the subgroup willistoni. Furthermore, the
elements hobo, BuT2, and mar have different
evolutionary histories. The transposon differences among D.
willistoni strains, such as variation in the number, structure, and
chromosomal distribution of hAT transposons, could reflect the
genomic and chromosomal plasticity of D. willistoni species in
adapting to highly variable environments.
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Affiliation(s)
- Natasha Ávila Bertocchi
- Universidade Federal do Rio Grande do Sul, Programa de Pós-Graduação em Genética e Biologia Molecular, Porto Alegre, RS, Brazil
| | - Thays Duarte de Oliveira
- Universidade Federal do Rio Grande do Sul, Programa de Pós-Graduação em Biologia Animal, Porto Alegre, RS, Brazil
| | - Maríndia Deprá
- Universidade Federal do Rio Grande do Sul, Programa de Pós-Graduação em Genética e Biologia Molecular, Porto Alegre, RS, Brazil.,Universidade Federal do Rio Grande do Sul, Programa de Pós-Graduação em Biologia Animal, Porto Alegre, RS, Brazil
| | - Beatriz Goñi
- Universidad de la República, Facultad de Ciencias, Montevideo, Uruguay
| | - Vera Lúcia S Valente
- Universidade Federal do Rio Grande do Sul, Programa de Pós-Graduação em Genética e Biologia Molecular, Porto Alegre, RS, Brazil.,Universidade Federal do Rio Grande do Sul, Programa de Pós-Graduação em Biologia Animal, Porto Alegre, RS, Brazil
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4
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What Have We Learned in 30 Years of Investigations on Bari Transposons? Cells 2022; 11:cells11030583. [PMID: 35159391 PMCID: PMC8834629 DOI: 10.3390/cells11030583] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 02/03/2022] [Accepted: 02/07/2022] [Indexed: 12/17/2022] Open
Abstract
Transposable elements (TEs) have been historically depicted as detrimental genetic entities that selfishly aim at perpetuating themselves, invading genomes, and destroying genes. Scientists often co-opt "special" TEs to develop new and powerful genetic tools, that will hopefully aid in changing the future of the human being. However, many TEs are gentle, rarely unleash themselves to harm the genome, and bashfully contribute to generating diversity and novelty in the genomes they have colonized, yet they offer the opportunity to develop new molecular tools. In this review we summarize 30 years of research focused on the Bari transposons. Bari is a "normal" transposon family that has colonized the genomes of several Drosophila species and introduced genomic novelties in the melanogaster species. We discuss how these results have contributed to advance the field of TE research and what future studies can still add to the current knowledge.
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5
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Yushkova E. Involvement of DNA Repair Genes and System of Radiation-Induced Activation of Transposons in Formation of Transgenerational Effects. Front Genet 2020; 11:596947. [PMID: 33329741 PMCID: PMC7729008 DOI: 10.3389/fgene.2020.596947] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 11/04/2020] [Indexed: 11/13/2022] Open
Abstract
The study of the genetic basis of the manifestation of radiation-induced effects and their transgenerational inheritance makes it possible to identify the mechanisms of adaptation and possible effective strategies for the survival of organisms in response to chronic radioactive stress. One persistent hypothesis is that the activation of certain genes involved in cellular defense is a specific response of the cell to irradiation. There is also data indicating the important role of transposable elements in the formation of radiosensitivity/radioresistance of biological systems. In this work, we studied the interaction of the systems of hobo transposon activity and DNA repair in the cell under conditions of chronic low-dose irradiation and its participation in the inheritance of radiation-induced transgenerational instability in Drosophila. Our results showed a significant increase of sterility and locus-specific mutability, a decrease of survival, fertility and genome stability (an increase the frequency of dominant lethal mutations and DNA damage) in non-irradiated F1/F2 offspring of irradiated parents with dysfunction of the mus304 gene which is responsible for excision and post-replicative recombination repair and repair of double-stranded DNA breaks. The combined action of dysfunction of the mus309 gene and transpositional activity of hobo elements also led to the transgenerational effects of irradiation but only in the F1 offspring. Dysfunction of the genes of other DNA repair systems (mus101 and mus210) showed no visible effects inherited from irradiated parents subjected to hobo transpositions. The mei-41 gene showed specificity in this type of interaction, which consists in its higher efficiency in sensing events induced by transpositional activity rather than irradiation.
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Affiliation(s)
- Elena Yushkova
- Department of Radioecology, Institute of Biology of Komi Scientific Centre of the Ural Branch of the Russian Academy of Science, Syktyvkar, Russia
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6
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Yushkova E. Effects of ionizing radiation at Drosophila melanogaster with differently active hobo transposons. Int J Radiat Biol 2019; 95:1564-1572. [PMID: 31287364 DOI: 10.1080/09553002.2019.1642534] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Purpose: The role of transposable elements in formation of radiobiological effects is understudied and contradictory. The aim of this study was to investigate the response of Drosophila melanogaster to irradiation depending on the level of activity hobo transposons and the role of hobo transposons in formation of ionizing radiation late effects.Materials and methods: The individuals of Drosophila melanogaster with different level activity of hobo-elements were exposed to acute irradiation in doses of 1-100 Gy at early ontogenesis stages. The reaction of individuals to exposure was studied using the larvae survival rate, morphological parameters of reproduction system, DNA damage rate, and mutability of mini-white locus.Results: We found the pronounced linear deferred effects of irradiation for animals with a high activity level of full-size hobo copies. The radiosensitivity of individuals with a mean level of activity transposon was whether higher or did not differ from the radiosensitivity of animals with a low activity hobo.Conclusion: The obtained results suggest that full-size hobo-elements with a high activity level (less often with a mean activity level) are responsible for delayed deleterious irradiation effects.
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Affiliation(s)
- Elena Yushkova
- Institute of Biology of Komi Science Centre of the Ural Branch of the Russian Academy of Sciences, Syktyvkar, Russia
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7
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Solares EA, Chakraborty M, Miller DE, Kalsow S, Hall K, Perera AG, Emerson JJ, Hawley RS. Rapid Low-Cost Assembly of the Drosophila melanogaster Reference Genome Using Low-Coverage, Long-Read Sequencing. G3 (BETHESDA, MD.) 2018; 8:3143-3154. [PMID: 30018084 PMCID: PMC6169397 DOI: 10.1534/g3.118.200162] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 07/03/2018] [Indexed: 12/27/2022]
Abstract
Accurate and comprehensive characterization of genetic variation is essential for deciphering the genetic basis of diseases and other phenotypes. A vast amount of genetic variation stems from large-scale sequence changes arising from the duplication, deletion, inversion, and translocation of sequences. In the past 10 years, high-throughput short reads have greatly expanded our ability to assay sequence variation due to single nucleotide polymorphisms. However, a recent de novo assembly of a second Drosophila melanogaster reference genome has revealed that short read genotyping methods miss hundreds of structural variants, including those affecting phenotypes. While genomes assembled using high-coverage long reads can achieve high levels of contiguity and completeness, concerns about cost, errors, and low yield have limited widespread adoption of such sequencing approaches. Here we resequenced the reference strain of D. melanogaster (ISO1) on a single Oxford Nanopore MinION flow cell run for 24 hr. Using only reads longer than 1 kb or with at least 30x coverage, we assembled a highly contiguous de novo genome. The addition of inexpensive paired reads and subsequent scaffolding using an optical map technology achieved an assembly with completeness and contiguity comparable to the D. melanogaster reference assembly. Comparison of our assembly to the reference assembly of ISO1 uncovered a number of structural variants (SVs), including novel LTR transposable element insertions and duplications affecting genes with developmental, behavioral, and metabolic functions. Collectively, these SVs provide a snapshot of the dynamics of genome evolution. Furthermore, our assembly and comparison to the D. melanogaster reference genome demonstrates that high-quality de novo assembly of reference genomes and comprehensive variant discovery using such assemblies are now possible by a single lab for under $1,000 (USD).
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Affiliation(s)
- Edwin A Solares
- Department of Ecology and Evolutionary Biology, University of California Irvine, CA
| | - Mahul Chakraborty
- Department of Ecology and Evolutionary Biology, University of California Irvine, CA
| | - Danny E Miller
- Stowers Institute for Medical Research, Kansas City, MO
- MD-PhD Physician Scientist Training Program, University of Kansas Medical Center, Kansas City, KS
| | - Shannon Kalsow
- Department of Ecology and Evolutionary Biology, University of California Irvine, CA
| | - Kate Hall
- Stowers Institute for Medical Research, Kansas City, MO
| | | | - J J Emerson
- Department of Ecology and Evolutionary Biology, University of California Irvine, CA
| | - R Scott Hawley
- Stowers Institute for Medical Research, Kansas City, MO
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS
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8
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Loreto ELS, Deprá M, Diesel JF, Panzera Y, Valente-Gaiesky VLS. Drosophila relics hobo and hobo-MITEs transposons as raw material for new regulatory networks. Genet Mol Biol 2018; 41:198-205. [PMID: 29668013 PMCID: PMC5913719 DOI: 10.1590/1678-4685-gmb-2017-0068] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 08/01/2017] [Indexed: 12/22/2022] Open
Abstract
Hypermutable strains of Drosophila simulans have been studied
for 20 years. Several mutants were isolated and characterized, some of which had
phenotypes associated with alteration in development; for example, showing
ectopic legs with eyes being expressed in place of antennae. The causal agent of
this hypermutability is a non-autonomous hobo-related sequence
(hoboVA). Around 100 mobilizable copies of this element are
present in the D. simulans genome, and these are likely
mobilized by the autonomous and canonical hobo element. We have
shown that hoboVA has transcription factor binding sites for
the developmental genes, hunchback and
even-skipped, and that this transposon is expressed in
embryos, following the patterns of these genes. We suggest that
hobo and hobo-related elements can be
material for the emergence of new regulatory networks.
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Affiliation(s)
- Elgion L S Loreto
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.,Departamento de Bioquímica e Biologia Molecular (CCNE), Universidade Federal de Santa Maria (UFSM), Santa Maria, RS, Brazil
| | - Maríndia Deprá
- Departamento de Genética, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - José F Diesel
- Departamento de Bioquímica e Biologia Molecular (CCNE), Universidade Federal de Santa Maria (UFSM), Santa Maria, RS, Brazil
| | - Yanina Panzera
- Departamento de Genetica, Universidad de la República de Uruguay (UDELAR), Montevideo, Uruguay
| | - Vera Lucia S Valente-Gaiesky
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.,Departamento de Genética, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
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9
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Ragagnin GT, Bernardo LP, Loreto ELS. Unraveling the evolutionary scenario of the hobo element in populations of Drosophila melanogaster and D. simulans in South America using the TPE repeats as markers. Genet Mol Biol 2016; 39:145-50. [PMID: 27007908 PMCID: PMC4807377 DOI: 10.1590/1678-4685-gmb-2015-0049] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Accepted: 08/11/2015] [Indexed: 11/22/2022] Open
Abstract
Transposable elements (TEs) are nucleotide sequences found in most studied genomes. These elements are highly diversified and have a large variation in nucleotide structure and mechanisms of transposition. hobo is a member of class II, belonging to hAT superfamily, described inDrosophila melanogaster, and it presents in its Open Reading Frame, a repetitive region encoding the amino acids threonine-proline-glutamic acid (TPE), which shows variability in the number of repeats in some regions of the world. Due to this variability some evolutionary scenarios of the hobo element are discussed, such as the scenario of the invasion of hobo element in populations ofD. melanogaster. In the present study, we investigated 22 DNA sequences of D. melanogaster and seven sequences ofD. simulans, both from South America, to check the number of repetitions of TPE, in order to clarify the evolutionary scenario of thehobo element in these populations. Our results showed a monomorphism in populations of both species in South America, with only three TPE repeats. Hence, we discuss and propose an evolutionary scenario of the invasion of the hobo element in populations of D. melanogaster and D. simulans.
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Affiliation(s)
| | | | - Elgion L S Loreto
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
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10
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Wallau GL, Capy P, Loreto E, Hua-Van A. Genomic landscape and evolutionary dynamics of mariner transposable elements within the Drosophila genus. BMC Genomics 2014; 15:727. [PMID: 25163909 PMCID: PMC4161770 DOI: 10.1186/1471-2164-15-727] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 08/01/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The mariner family of transposable elements is one of the most widespread in the Metazoa. It is subdivided into several subfamilies that do not mirror the phylogeny of these species, suggesting an ancient diversification. Previous hybridization and PCR studies allowed a partial survey of mariner diversity in the Metazoa. In this work, we used a comparative genomics approach to access the genus-wide diversity and evolution of mariner transposable elements in twenty Drosophila sequenced genomes. RESULTS We identified 36 different mariner lineages belonging to six distinct subfamilies, including a subfamily not described previously. Wide variation in lineage abundance and copy number were observed among species and among mariner lineages, suggesting continuous turn-over. Most mariner lineages are inactive and contain a high proportion of damaged copies. We showed that, in addition to substitutions that rapidly inactivate copies, internal deletion is a major mechanism contributing to element decay and the generation of non-autonomous sublineages. Hence, 23% of copies correspond to several Miniature Inverted-repeat Transposable Elements (MITE) sublineages, the first ever described in Drosophila for mariner. In the most successful MITEs, internal deletion is often associated with internal rearrangement, which sheds light on the process of MITE origin. The estimation of the transposition rates over time revealed that all lineages followed a similar progression consisting of a rapid amplification burst followed by a rapid decrease in transposition. We detected some instances of multiple or ongoing transposition bursts. Different amplification times were observed for mariner lineages shared by different species, a finding best explained by either horizontal transmission or a reactivation process. Different lineages within one species have also amplified at different times, corresponding to successive invasions. Finally, we detected a preference for insertion into short TA-rich regions, which appears to be specific to some subfamilies. CONCLUSIONS This analysis is the first comprehensive survey of this family of transposable elements at a genus scale. It provides precise measures of the different evolutionary processes that were hypothesized previously for this family based on PCR data analysis. mariner lineages were observed at almost all "life cycle" stages: recent amplification, subsequent decay and potential (re)-invasion or invasion of genomes.
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Affiliation(s)
- Gabriel Luz Wallau
- Pós-Graduaíão em Biodiversidade Animal, Universidade Federal de Santa Maria, Santa Maria, Brasil.
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11
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Rossato DO, Ludwig A, Deprá M, Loreto ELS, Ruiz A, Valente VLS. BuT2 is a member of the third major group of hAT transposons and is involved in horizontal transfer events in the genus Drosophila. Genome Biol Evol 2014; 6:352-65. [PMID: 24459285 PMCID: PMC3942097 DOI: 10.1093/gbe/evu017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/15/2014] [Indexed: 12/24/2022] Open
Abstract
The hAT superfamily comprises a large and diverse array of DNA transposons found in all supergroups of eukaryotes. Here we characterized the Drosophila buzzatii BuT2 element and found that it harbors a five-exon gene encoding a 643-aa putatively functional transposase. A phylogeny built with 85 hAT transposases yielded, in addition to the two major groups already described, Ac and Buster, a third one comprising 20 sequences that includes BuT2, Tip100, hAT-4_BM, and RP-hAT1. This third group is here named Tip. In addition, we studied the phylogenetic distribution and evolution of BuT2 by in silico searches and molecular approaches. Our data revealed BuT2 was, most often, vertically transmitted during the evolution of genus Drosophila being lost independently in several species. Nevertheless, we propose the occurrence of three horizontal transfer events to explain its distribution and conservation among species. Another aspect of BuT2 evolution and life cycle is the presence of short related sequences, which contain similar 5' and 3' regions, including the terminal inverted repeats. These sequences that can be considered as miniature inverted repeat transposable elements probably originated by internal deletion of complete copies and show evidences of recent mobilization.
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Affiliation(s)
- Dirleane Ottonelli Rossato
- Programa de Pós-Graduação em
Ecologia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do
Sul, Brazil
| | - Adriana Ludwig
- Laboratório de Genômica Funcional, Instituto
Carlos Chagas (ICC), Fiocruz-PR, Curitiba, Paraná, Brazil
| | - Maríndia Deprá
- Programa de Pós-Graduação em Biologia
Animal, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do
Sul, Brazil
- Departamento de Genética, Universidade Federal do
Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do Sul, Brazil
| | - Elgion L. S. Loreto
- Programa de Pós-Graduação em
Genética e Biologia Molecular Universidade Federal do Rio Grande do Sul (UFRGS),
Porto Alegre, Rio Grande do Sul, Brazil
- Departamento de Biologia, Universidade Federal de Santa
Maria (UFSM), Santa Maria, Rio Grande do Sul, Brazil
| | - Alfredo Ruiz
- Departament de Genètica i Microbiologia, Facultat
de Biociènces, Universitat Autònoma de Barcelona, Spain
| | - Vera L. S. Valente
- Programa de Pós-Graduação em Biologia
Animal, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do
Sul, Brazil
- Departamento de Genética, Universidade Federal do
Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do Sul, Brazil
- Programa de Pós-Graduação em
Genética e Biologia Molecular Universidade Federal do Rio Grande do Sul (UFRGS),
Porto Alegre, Rio Grande do Sul, Brazil
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12
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hobo-brothers elements and their time and place for horizontal transfer. Genetica 2013; 141:471-8. [PMID: 24158527 DOI: 10.1007/s10709-013-9746-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 10/18/2013] [Indexed: 01/02/2023]
Abstract
Transposable elements (TEs) are ubiquitous components of nearly all genomes studied. These elements are highly variable in copy number, molecular structure and transposition strategies. They can move within and between genomes, thus increasing their copy numbers and avoiding being eliminated by stochastic and deterministic processes. hobo is a class II element isolated from Drosophila melanogaster. Previous phylogenetic analyses have shown that the canonical hobo element from D. melanogaster has a sister group formed by sequences found in D. willistoni (called howilli2) and D. mojavensis (called homo1). In the present study, we investigated 36 Drosophilidae species for sequences similar to howilli2 and homo1 using degenerate primers. Additionally, in silico searches were performed in 21 available Drosophila genomes. The obtained sequences formed a monophyletic sister group with the canonical hobo element; we termed these sequences 'hobo-brothers' elements. These elements showed a patch distribution and incongruities with the TE and host species phylogenies, suggesting possible cases of horizontal transfer (HT). Species that possess hobo-brothers sequences are from the New World, mainly Neotropical areas. In addition, the estimated divergence of the sequences found showed that these elements are or were recently active; the large number of HT events observed suggests that these elements could be experiencing an expansion process in Neotropical genomes. A comparison of these results with the literature is discussed with regard to the importance of the time and location of horizontal transposon transfer events.
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Abstract
Background Miniature inverted-repeat transposable elements (MITEs) are short, nonautonomous DNA elements flanked by subterminal or terminal inverted repeats (TIRs) with no coding capacity. MITEs were originally recognized as important components of plant genomes, where they can attain extremely high copy numbers, and are also found in several animal genomes, including mosquitoes, fish and humans. So far, few MITEs have been described in Drosophila. Results Herein we describe the distribution and evolution of Mar, a MITE family of hAT transposons, in Drosophilidae species. In silico searches and PCR screening showed that Mar distribution is restricted to the willistoni subgroup of the Drosophila species, and a phylogenetic analysis of Mar indicates that this element may have originated prior to the diversification of these species. Most of the Mar copies in D. willistoni present conserved target site duplications and TIRs, indicating recent mobilization of these sequences. We also identified relic copies of potentially full-length Mar transposon in D. tropicalis and D. willistoni. The phylogenetic relationship among transposases from the putative full-length Mar and other hAT superfamily elements revealed that Mar is placed into the recently determined Buster group of hAT transposons. Conclusion On the basis of the obtained data, we can suggest that the origin of these Mar MITEs occurred before the subgroup willistoni speciation, which started about 5.7 Mya. The Mar relic transposase existence indicates that these MITEs originated by internal deletions and suggests that the full-length transposon was recently functional in D. willistoni, promoting Mar MITEs mobilization.
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Kim YJ, Hice RH, O'Brochta DA, Atkinson PW. DNA sequence requirements for hobo transposable element transposition in Drosophila melanogaster. Genetica 2011; 139:985-97. [PMID: 21805320 DOI: 10.1007/s10709-011-9600-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Accepted: 07/18/2011] [Indexed: 01/08/2023]
Abstract
We have conducted a structure and functional analysis of the hobo transposable element of Drosophila melanogaster. A minimum of 141 bp of the left (L) end and 65 bp of the right (R) end of the hobo were shown to contain sequences sufficient for transposition. Both ends of hobo contain multiple copies of the motifs GGGTG and GTGGC and we show that the frequency of hobo transposition increases as a function of the copy number of these motifs. The R end of hobo contains a unique 12 bp internal inverted repeat that is identical to the hobo terminal inverted repeats. We show that this internal inverted repeat suppresses transposition activity in a hobo element containing an intact L end and only 475 bp of the R end. In addition to establishing cis-sequences requirements for transposition, we analyzed trans-sequence effects of the hobo transposase. We show a hobo transposase lacking the first 49 amino acids catalyzed hobo transposition at a higher frequency than the full-length transposase suggesting that, similar to the related Ac transposase, residues at the amino end of the transposase reduce transposition. Finally, we compared target site sequences of hobo with those of the related Hermes element and found both transposons have strong preferences for the same insertion sites.
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Affiliation(s)
- Yu Jung Kim
- Graduate Program in Department of Biochemistry and Molecular Biology, University of California, Riverside, CA 92521, USA
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15
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hAT transposable elements and their derivatives: an analysis in the 12 Drosophila genomes. Genetica 2010; 138:649-55. [PMID: 20127503 DOI: 10.1007/s10709-010-9439-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2009] [Accepted: 01/19/2010] [Indexed: 10/19/2022]
Abstract
Transposable elements (TEs) comprise a significant fraction of the genome, and some models of the TE "life cycle" suggest that, in the last phases of the cycle, TEs should be represented, in the genomes, by inactive and degenerated copies. In this study, we analyzed, using a bioinformatics approach, the autonomous hAT elements and their derivatives (active non-autonomous, MITE relatives and degenerated copies) in 12 Drosophila genomes. We found 28 hAT elements that had derivatives. Most copies had features that suggested that they were active, while only a few degenerated copies were found. Because hAT elements comprise an evolutionarily old superfamily, one should expect to find many degenerated copies within the genome, although this was not observed in our study. These results suggest that primarily active copies of hAT elements are maintained in the euchromatic regions of the genome and that degenerated copies are removed from the genome by natural selection.
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16
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Deprá M, Valente VLDS, Margis R, Loreto ELS. The hobo transposon and hobo-related elements are expressed as developmental genes in Drosophila. Gene 2009; 448:57-63. [PMID: 19720121 DOI: 10.1016/j.gene.2009.08.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Revised: 08/10/2009] [Accepted: 08/22/2009] [Indexed: 02/02/2023]
Abstract
Transposable elements comprise a significant part of genomes and are involved in their evolvability. The hobo element is found as an active class II transposable element in Drosophila melanogaster that is able to induce gonadal dysgenesis. Some hobo-related sequences (hRSs) are thought to be relics of old "hobo" invasions, and are therefore ancient genomic constituents. However, some of these hRSs are still mobile. The present study analyzed the expression pattern of hobo and a particular type of hRSs, hobo(VAHS). Both elements were shown to be expressed as sense and antisense mRNA transcripts. Expression analysis in whole mount embryos revealed a pattern similar to that of some developmental regulatory genes. Here we suggest that cis-regulatory sequences similar to those in developmental genes exist in hobo sequences. Therefore, hobo mobilization may contribute to the development of new regulatory networks during genomic evolution.
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Affiliation(s)
- Maríndia Deprá
- Programa de Pós-Graduação em Genética e Biologia Molecular, Departamento de Genética, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
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