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Beck RM, Voss RS, Jansa SA. Craniodental Morphology and Phylogeny of Marsupials. BULLETIN OF THE AMERICAN MUSEUM OF NATURAL HISTORY 2022. [DOI: 10.1206/0003-0090.457.1.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Robin M.D. Beck
- School of Science, Engineering and Environment University of Salford, U.K. School of Biological, Earth & Environmental Sciences University of New South Wales, Australia Division of Vertebrate Zoology (Mammalogy) American Museum of Natural History
| | - Robert S. Voss
- Division of Vertebrate Zoology (Mammalogy) American Museum of Natural History
| | - Sharon A. Jansa
- Bell Museum and Department of Ecology, Evolution, and Behavior University of Minnesota
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2
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Shridharan RV, Kalakuntla N, Chirmule N, Tiwari B. The Happy Hopping of Transposons: The Origins of V(D)J Recombination in Adaptive Immunity. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.836066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Nearly 50% of the human genome is derived from transposable elements (TEs). Though dysregulated transposons are deleterious to humans and can lead to diseases, co-opted transposons play an important role in generating alternative or new DNA sequence combinations to perform novel cellular functions. The appearance of an adaptive immune system in jawed vertebrates, wherein the somatic rearrangement of T and B cells generates a repertoire of antibodies and receptors, is underpinned by Class II TEs. This review follows the evolution of recombination activation genes (RAGs), components of adaptive immunity, from TEs, focusing on the structural and mechanistic similarities between RAG recombinases and DNA transposases. As evolution occurred from a transposon precursor, DNA transposases developed a more targeted and constrained mechanism of mobilization. As DNA repair is integral to transposition and recombination, we note key similarities and differences in the choice of DNA repair pathways following these processes. Understanding the regulation of V(D)J recombination from its evolutionary origins may help future research to specifically target RAG proteins to rectify diseases associated with immune dysregulation.
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Skobel O, Kosovsky G, Glazko V. Candidate vectors of horizontal transfer of BovB retrotransposon. BIO WEB OF CONFERENCES 2022. [DOI: 10.1051/bioconf/20224301014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The horizontal transfer of retrotransposons has a significant impact on the regulatory system of a multicellular organism, but the biological basis of horizontal transfer has been sufficiently studied up to date. Earlier, we identified the conserved sequence of retrotransposons recombination products of the bovine chromosome 1 nucleotide sequence region. This conserved sequence has a high percent identity with LINE BovB, which is widely known as horizontal transfer participant. The current study analyzes the presence of the conserved sequence of retrotransposons recombination products of cattle in members of different taxonomic groups to detect potential vectors of horizontal transfer. It was shown that the conserved sequence with a high percent identity can be found in 43 members of different species, including eukaryotes, prokaryotes and viruses. The identified potential vectors of horizontal retrotransposon transfer associated with various diseases of farm animals are of particular interest. Such potential vectors are hemiparasites Babesia ovata and Babesia bigemina (pathogens causing babesiosis), bacterium Clostridium botulinum (the causative agent of botulism), Jaagsiekte sheep retrovirus (the causative agent of lung cancer in sheep). They all have regions with a high percent identity (not lower than 95%) to the studied bovine conserved sequence. Thus, we identify new potential vectors of horizontal retrotransposon transfer as well as the possible influence of retrotransposons on regulatory networks affecting host protection from infectious diseases.
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Peel E, Silver L, Brandies P, Hogg CJ, Belov K. A reference genome for the critically endangered woylie, Bettongia penicillata ogilbyi. GIGABYTE 2021; 2021:gigabyte35. [PMID: 36824341 PMCID: PMC9650285 DOI: 10.46471/gigabyte.35] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 12/08/2021] [Indexed: 11/09/2022] Open
Abstract
Biodiversity is declining globally, and Australia has one of the worst extinction records for mammals. The development of sequencing technologies means that genomic approaches are now available as important tools for wildlife conservation and management. Despite this, genome sequences are available for only 5% of threatened Australian species. Here we report the first reference genome for the woylie (Bettongia penicillata ogilbyi), a critically endangered marsupial from Western Australia, and the first genome within the Potoroidae family. The woylie reference genome was generated using Pacific Biosciences HiFi long-reads, resulting in a 3.39 Gbp assembly with a scaffold N50 of 6.49 Mbp and 86.5% complete mammalian BUSCOs. Assembly of a global transcriptome from pouch skin, tongue, heart and blood RNA-seq reads was used to guide annotation with Fgenesh++, resulting in the annotation of 24,655 genes. The woylie reference genome is a valuable resource for conservation, management and investigations into disease-induced decline of this critically endangered marsupial.
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Affiliation(s)
- Emma Peel
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
| | - Luke Silver
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
| | - Parice Brandies
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
| | - Carolyn J. Hogg
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
| | - Katherine Belov
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia, Corresponding author. E-mail:
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5
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Petersen M, Winter S, Coimbra R, J de Jong M, Kapitonov VV, Nilsson MA. Population analysis of retrotransposons in giraffe genomes supports RTE decline and widespread LINE1 activity in Giraffidae. Mob DNA 2021; 12:27. [PMID: 34836553 PMCID: PMC8620236 DOI: 10.1186/s13100-021-00254-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 10/25/2021] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND The majority of structural variation in genomes is caused by insertions of transposable elements (TEs). In mammalian genomes, the main TE fraction is made up of autonomous and non-autonomous non-LTR retrotransposons commonly known as LINEs and SINEs (Long and Short Interspersed Nuclear Elements). Here we present one of the first population-level analysis of TE insertions in a non-model organism, the giraffe. Giraffes are ruminant artiodactyls, one of the few mammalian groups with genomes that are colonized by putatively active LINEs of two different clades of non-LTR retrotransposons, namely the LINE1 and RTE/BovB LINEs as well as their associated SINEs. We analyzed TE insertions of both types, and their associated SINEs in three giraffe genome assemblies, as well as across a population level sampling of 48 individuals covering all extant giraffe species. RESULTS The comparative genome screen identified 139,525 recent LINE1 and RTE insertions in the sampled giraffe population. The analysis revealed a drastically reduced RTE activity in giraffes, whereas LINE1 is still actively propagating in the genomes of extant (sub)-species. In concert with the extremely low activity of the giraffe RTE, we also found that RTE-dependent SINEs, namely Bov-tA and Bov-A2, have been virtually immobile in the last 2 million years. Despite the high current activity of the giraffe LINE1, we did not find evidence for the presence of currently active LINE1-dependent SINEs. TE insertion heterozygosity rates differ among the different (sub)-species, likely due to divergent population histories. CONCLUSIONS The horizontally transferred RTE/BovB and its derived SINEs appear to be close to inactivation and subsequent extinction in the genomes of extant giraffe species. This is the first time that the decline of a TE family has been meticulously analyzed from a population genetics perspective. Our study shows how detailed information about past and present TE activity can be obtained by analyzing large-scale population-level genomic data sets.
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Affiliation(s)
- Malte Petersen
- Max Planck Institute of Immunobiology and Epigenetics, Stübeweg 51, 79108, Freiburg, Germany
| | - Sven Winter
- Senckenberg Biodiversity and Climate Research Centre, Senckenberganlage 25, 60325, Frankfurt am Main, Germany
| | - Raphael Coimbra
- Senckenberg Biodiversity and Climate Research Centre, Senckenberganlage 25, 60325, Frankfurt am Main, Germany
- Institute for Ecology, Evolution and Diversity, Goethe University, Max-von-Laue-Straße 13, 60438, Frankfurt am Main, Germany
| | - Menno J de Jong
- Senckenberg Biodiversity and Climate Research Centre, Senckenberganlage 25, 60325, Frankfurt am Main, Germany
| | - Vladimir V Kapitonov
- Senckenberg Biodiversity and Climate Research Centre, Senckenberganlage 25, 60325, Frankfurt am Main, Germany
- LOEWE Centre for Translational Biodiversity Genomics (LOEWE-TBG), Senckenberganlage 25, 60325, Frankfurt am Main, Germany
| | - Maria A Nilsson
- Senckenberg Biodiversity and Climate Research Centre, Senckenberganlage 25, 60325, Frankfurt am Main, Germany.
- LOEWE Centre for Translational Biodiversity Genomics (LOEWE-TBG), Senckenberganlage 25, 60325, Frankfurt am Main, Germany.
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6
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Between the Devil and the Deep Blue Sea: Non-Coding RNAs Associated with Transmissible Cancers in Tasmanian Devil, Domestic Dog and Bivalves. Noncoding RNA 2021; 7:ncrna7040072. [PMID: 34842768 PMCID: PMC8628904 DOI: 10.3390/ncrna7040072] [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] [Received: 10/06/2021] [Revised: 11/05/2021] [Accepted: 11/09/2021] [Indexed: 12/20/2022] Open
Abstract
Currently there are nine known examples of transmissible cancers in nature. They have been observed in domestic dog, Tasmanian devil, and six bivalve species. These tumours can overcome host immune defences and spread to other members of the same species. Non-coding RNAs (ncRNAs) are known to play roles in tumorigenesis and immune system evasion. Despite their potential importance in transmissible cancers, there have been no studies on ncRNA function in this context to date. Here, we present possible applications of the CRISPR/Cas system to study the RNA biology of transmissible cancers. Specifically, we explore how ncRNAs may play a role in the immortality and immune evasion ability of these tumours.
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Dias CAR, Kuhn GCS, Svartman M, Santos Júnior JED, Santos FR, Pinto CM, Perini FA. Identification and characterization of repetitive DNA in the genus Didelphis Linnaeus, 1758 (Didelphimorphia, Didelphidae) and the use of satellite DNAs as phylogenetic markers. Genet Mol Biol 2021; 44:e20200384. [PMID: 33877257 PMCID: PMC8056902 DOI: 10.1590/1678-4685-gmb-2020-0384] [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] [Received: 10/20/2020] [Accepted: 03/01/2021] [Indexed: 11/22/2022] Open
Abstract
Didelphis species have been shown to exhibit very conservative karyotypes, which mainly differ in their constitutive heterochromatin, known to be mostly composed by repetitive DNAs. In this study, we used genome skimming data combined with computational pipelines to identify the most abundant repetitive DNA families of Lutreolina crassicaudata and all six Didelphis species. We found that transposable elements (TEs), particularly LINE-1, endogenous retroviruses, and SINEs, are the most abundant mobile elements in the studied species. Despite overall similar TE proportions, we report that species of the D. albiventris group consistently present a less diverse TE composition and smaller proportions of LINEs and LTRs in their genomes than other studied species. We also identified four new putative satDNAs (sat206, sat907, sat1430 and sat2324) in the genomes of Didelphis species, which show differences in abundance and nucleotide composition. Phylogenies based on satDNA sequences showed well supported relationships at the species (sat1430) and groups of species (sat206) level, recovering topologies congruent with previous studies. Our study is one of the first attempts to present a characterization of the most abundant families of repetitive DNAs of Lutreolina and Didelphis species providing insights into the repetitive DNA composition in the genome landscape of American marsupials.
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Affiliation(s)
- Cayo Augusto Rocha Dias
- Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Laboratório de Evolução de Mamíferos, Belo Horizonte, MG, Brazil
| | - Gustavo C S Kuhn
- Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Laboratório de Citogenômica Evolutiva, Belo Horizonte, MG, Brazil
| | - Marta Svartman
- Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Laboratório de Citogenômica Evolutiva, Belo Horizonte, MG, Brazil
| | - José Eustáquio Dos Santos Júnior
- Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Laboratório de Biodiversidade e Evolução Molecular, Belo Horizonte, MG, Brazil
| | - Fabrício Rodrigues Santos
- Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Laboratório de Biodiversidade e Evolução Molecular, Belo Horizonte, MG, Brazil
| | - Christian Miguel Pinto
- Escuela Politécnica Nacional, Facultad de Ciencias, Departamento de Biologia, Quito, Ecuador
| | - Fernando Araújo Perini
- Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Laboratório de Evolução de Mamíferos, Belo Horizonte, MG, Brazil
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8
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Pappalardo AM, Ferrito V, Biscotti MA, Canapa A, Capriglione T. Transposable Elements and Stress in Vertebrates: An Overview. Int J Mol Sci 2021; 22:1970. [PMID: 33671215 PMCID: PMC7922186 DOI: 10.3390/ijms22041970] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 02/13/2021] [Accepted: 02/14/2021] [Indexed: 12/17/2022] Open
Abstract
Since their identification as genomic regulatory elements, Transposable Elements (TEs) were considered, at first, molecular parasites and later as an important source of genetic diversity and regulatory innovations. In vertebrates in particular, TEs have been recognized as playing an important role in major evolutionary transitions and biodiversity. Moreover, in the last decade, a significant number of papers has been published highlighting a correlation between TE activity and exposition to environmental stresses and dietary factors. In this review we present an overview of the impact of TEs in vertebrate genomes, report the silencing mechanisms adopted by host genomes to regulate TE activity, and finally we explore the effects of environmental and dietary factor exposures on TE activity in mammals, which is the most studied group among vertebrates. The studies here reported evidence that several factors can induce changes in the epigenetic status of TEs and silencing mechanisms leading to their activation with consequent effects on the host genome. The study of TE can represent a future challenge for research for developing effective markers able to detect precocious epigenetic changes and prevent human diseases.
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Affiliation(s)
- Anna Maria Pappalardo
- Department of Biological, Geological and Environmental Sciences-Section of Animal Biology "M. La Greca", University of Catania, Via Androne 81, 95124 Catania, Italy
| | - Venera Ferrito
- Department of Biological, Geological and Environmental Sciences-Section of Animal Biology "M. La Greca", University of Catania, Via Androne 81, 95124 Catania, Italy
| | - Maria Assunta Biscotti
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy
| | - Adriana Canapa
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy
| | - Teresa Capriglione
- Department of Biology, University of Naples "Federico II", Via Cinthia 21-Ed7, 80126 Naples, Italy
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Kitsoulis CV, Baxevanis AD, Abatzopoulos TJ. The occurrence of cancer in vertebrates: a mini review. ACTA ACUST UNITED AC 2020; 27:9. [PMID: 32528906 PMCID: PMC7282124 DOI: 10.1186/s40709-020-00119-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 06/01/2020] [Indexed: 12/26/2022]
Abstract
Neoplasia is a multilevel condition caused by irregularities over the genome, which can lead to a fatal result. To fully understand this phenomenon, an evolutionary challenge has risen during the last decades, away from human limits, driving the scientific quest into the wild life. The study of wild vertebrate populations in their natural habitats has shown that cancer is rather prominent. Thus, the diversity of vertebrates reported with some form of neoplasia is quite scattered through a variety of habitats. However, some species constitute exceptions by exhibiting cancer-protective features, driven by certain loci in their DNA. It is obvious that from an evolutionary standpoint, the incidence of cancer in different taxa is nowadays studied by seeking for patterns and their roots. The main purpose of the evolutionary approach is no other than to answer a fundamental question: Could cancer be ultimately regarded as another evolutionary force conducive to the formation or shaping-up of species?
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Affiliation(s)
- Christos V Kitsoulis
- Department of Genetics, Development & Molecular Biology, School of Biology, Faculty of Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | - Athanasios D Baxevanis
- Department of Genetics, Development & Molecular Biology, School of Biology, Faculty of Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | - Theodore J Abatzopoulos
- Department of Genetics, Development & Molecular Biology, School of Biology, Faculty of Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
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10
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Yang L, Scott L, Wichman HA. Tracing the history of LINE and SINE extinction in sigmodontine rodents. Mob DNA 2019; 10:22. [PMID: 31139266 PMCID: PMC6530004 DOI: 10.1186/s13100-019-0164-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 04/30/2019] [Indexed: 12/18/2022] Open
Abstract
Background L1 retrotransposons have co-evolved with their mammalian hosts for the entire history of mammals and currently compose ~ 20% of a mammalian genome. B1 retrotransposons are dependent on L1 for retrotransposition and span the evolutionary history of rodents since their radiation. L1s were found to have lost their activity in a group of South American rodents, the Sigmodontinae, and B1 inactivation preceded the extinction of L1 in the same group. Consequently, a basal group of sigmodontines have active L1s but inactive B1s and a derived clade have both inactive L1s and B1s. It has been suggested that B1s became extinct during a long period of L1 quiescence and that L1s subsequently reemerged in the basal group. Results Here we investigate the evolutionary histories of L1 and B1 in the sigmodontine rodents and show that L1 activity continued until after the L1-extinct clade and the basal group diverged. After the split, L1 had a small burst of activity in the former group, followed by extinction. In the basal group, activity was initially low but was followed by a dramatic increase in L1 activity. We found the last wave of B1 retrotransposition was large and probably preceded the split between the two rodent clades. Conclusions Given that L1s had been steadily retrotransposing during the time corresponding to B1 extinction and that the burst of B1 activity preceding B1 extinction was large, we conclude that B1 extinction was not a result of L1 quiescence. Rather, the burst of B1 activity may have contributed to L1 extinction both by competition with L1 and by putting strong selective pressure on the host to control retrotransposition. Electronic supplementary material The online version of this article (10.1186/s13100-019-0164-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lei Yang
- 1Department of Biological Sciences, University of Idaho, Moscow, ID USA.,2Institute for Bioinformatics and Evolutionary Studies, University of Idaho, Moscow, ID USA
| | - LuAnn Scott
- 1Department of Biological Sciences, University of Idaho, Moscow, ID USA.,2Institute for Bioinformatics and Evolutionary Studies, University of Idaho, Moscow, ID USA
| | - Holly A Wichman
- 1Department of Biological Sciences, University of Idaho, Moscow, ID USA.,2Institute for Bioinformatics and Evolutionary Studies, University of Idaho, Moscow, ID USA
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11
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Abstract
DAMBE is a comprehensive software package for genomic and phylogenetic data analysis on Windows, Linux, and Macintosh computers. New functions include imputing missing distances and phylogeny simultaneously (paving the way to build large phage and transposon trees), new bootstrapping/jackknifing methods for PhyPA (phylogenetics from pairwise alignments), and an improved function for fast and accurate estimation of the shape parameter of the gamma distribution for fitting rate heterogeneity over sites. Previous method corrects multiple hits for each site independently. DAMBE’s new method uses all sites simultaneously for correction. DAMBE, featuring a user-friendly graphic interface, is freely available from http://dambe.bio.uottawa.ca (last accessed, April 17, 2018).
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Affiliation(s)
- Xuhua Xia
- Department of Biology, University of Ottawa, Ottawa, ON, Canada.,Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON, Canada
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12
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Nimble and Ready to Mingle: Transposon Outbursts of Early Development. Trends Genet 2018; 34:806-820. [DOI: 10.1016/j.tig.2018.06.006] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 06/19/2018] [Accepted: 06/29/2018] [Indexed: 12/21/2022]
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13
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Xia X. Imputing missing distances in molecular phylogenetics. PeerJ 2018; 6:e5321. [PMID: 30065887 PMCID: PMC6063210 DOI: 10.7717/peerj.5321] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 07/05/2018] [Indexed: 12/27/2022] Open
Abstract
Missing data are frequently encountered in molecular phylogenetics, but there has been no accurate distance imputation method available for distance-based phylogenetic reconstruction. The general framework for distance imputation is to explore tree space and distance values to find an optimal combination of output tree and imputed distances. Here I develop a least-square method coupled with multivariate optimization to impute multiple missing distance in a distance matrix or from a set of aligned sequences with missing genes so that some sequences share no homologous sites (whose distances therefore need to be imputed). I show that phylogenetic trees can be inferred from distance matrices with about 10% of distances missing, and the accuracy of the resulting phylogenetic tree is almost as good as the tree from full information. The new method has the advantage over a recently published one in that it does not assume a molecular clock and is more accurate (comparable to maximum likelihood method based on simulated sequences). I have implemented the function in DAMBE software, which is freely available at http://dambe.bio.uottawa.ca.
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Affiliation(s)
- Xuhua Xia
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada.,Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Ontario, Canada
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14
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Kealy S, Beck R. Total evidence phylogeny and evolutionary timescale for Australian faunivorous marsupials (Dasyuromorphia). BMC Evol Biol 2017; 17:240. [PMID: 29202687 PMCID: PMC5715987 DOI: 10.1186/s12862-017-1090-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 11/22/2017] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND The order Dasyuromorphia is a diverse radiation of faunivorous marsupials, comprising >80 modern species in Australia and New Guinea. It includes dasyurids, the numbat (the myrmecobiid Myrmecobius fasciatus) and the recently extinct thylacine (the thylacinid Thylacinus cyncocephalus). There is also a diverse fossil record of dasyuromorphians and "dasyuromorphian-like" taxa known from Australia. We present the first total evidence phylogenetic analyses of the order, based on combined morphological and molecular data (including a novel set of 115 postcranial characters), to resolve relationships and calculate divergence dates. We use this information to analyse the diversification dynamics of modern dasyuromorphians. RESULTS Our morphology-only analyses are poorly resolved, but our molecular and total evidence analyses confidently resolve most relationships within the order, and are strongly congruent with recent molecular studies. Thylacinidae is the first family to diverge within the order, and there is strong support for four tribes within Dasyuridae (Dasyurini, Phascogalini, Planigalini and Sminthopsini). Among fossil taxa, Ankotarinja and Keeuna do not appear to be members of Dasyuromorphia, whilst Barinya and Mutpuracinus are of uncertain relationships within the order. Divergence dates calculated using total evidence tip-and-node dating are younger than both molecular node-dating and total evidence tip-dating, but appear more congruent with the fossil record and are relatively insensitive to calibration strategy. The tip-and-node divergence dates indicate that Dasyurini, Phascogalini and Sminthopsini began to radiate almost simultaneously during the middle-to-late Miocene (11.5-13.1 MYA; composite 95% HPD: 9.5-15.9 MYA); the median estimates for these divergences are shortly after a drop in global temperatures (the middle Miocene Climatic Transition), and coincide with a faunal turnover event in the mammalian fossil record of Australia. Planigalini radiated much later, during the latest Miocene to earliest Pliocene (6.5 MYA; composite 95% HPD: 4.4-8.9 MYA); the median estimates for these divergences coincide with an increase in grass pollen in the Australian palynological record that suggests the development of more open habitats, which are preferred by modern planigale species. CONCLUSIONS Our results provide a phylogenetic and temporal framework for interpreting the evolution of modern and fossil dasyuromorphians, but future progress will require a much improved fossil record.
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Affiliation(s)
- Shimona Kealy
- Archaeology and Natural History, School of Culture, History and Language, College of Asia and the Pacific, Australian National University, Acton, ACT Australia
| | - Robin Beck
- School of Environment and Life Sciences, University of Salford, Salford, M5 4WT UK
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15
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Dodt WG, Gallus S, Phillips MJ, Nilsson MA. Resolving kangaroo phylogeny and overcoming retrotransposon ascertainment bias. Sci Rep 2017; 7:16811. [PMID: 29196678 PMCID: PMC5711953 DOI: 10.1038/s41598-017-16148-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 10/26/2017] [Indexed: 01/31/2023] Open
Abstract
Reconstructing phylogeny from retrotransposon insertions is often limited by access to only a single reference genome, whereby support for clades that do not include the reference taxon cannot be directly observed. Here we have developed a new statistical framework that accounts for this ascertainment bias, allowing us to employ phylogenetically powerful retrotransposon markers to explore the radiation of the largest living marsupials, the kangaroos and wallabies of the genera Macropus and Wallabia. An exhaustive in silico screening of the tammar wallaby (Macropus eugenii) reference genome followed by experimental screening revealed 29 phylogenetically informative retrotransposon markers belonging to a family of endogenous retroviruses. We identified robust support for the enigmatic swamp wallaby (Wallabia bicolor) falling within a paraphyletic genus, Macropus. Our statistical approach provides a means to test for incomplete lineage sorting and introgression/hybridization in the presence of the ascertainment bias. Using retrotransposons as “molecular fossils”, we reveal one of the most complex patterns of hemiplasy yet identified, during the rapid diversification of kangaroos and wallabies. Ancestral state reconstruction incorporating the new retrotransposon phylogenetic information reveals multiple independent ecological shifts among kangaroos into more open habitats, coinciding with the Pliocene onset of increased aridification in Australia from ~3.6 million years ago.
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Affiliation(s)
- William G Dodt
- School of Earth, Environmental and Biological Sciences, Queensland University of Technology (QUT), 2 George Street, Brisbane, Australia.
| | - Susanne Gallus
- Senckenberg Biodiversity and Climate Research Centre (BiK-F) Frankfurt, Senckenberg Gesellschaft fuer Naturforschung, Senckenberganlage 25, Frankfurt am Main, Germany
| | - Matthew J Phillips
- School of Earth, Environmental and Biological Sciences, Queensland University of Technology (QUT), 2 George Street, Brisbane, Australia.
| | - Maria A Nilsson
- Senckenberg Biodiversity and Climate Research Centre (BiK-F) Frankfurt, Senckenberg Gesellschaft fuer Naturforschung, Senckenberganlage 25, Frankfurt am Main, Germany.
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16
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Ivancevic AM, Kortschak RD, Bertozzi T, Adelson DL. LINEs between Species: Evolutionary Dynamics of LINE-1 Retrotransposons across the Eukaryotic Tree of Life. Genome Biol Evol 2016; 8:3301-3322. [PMID: 27702814 PMCID: PMC5203782 DOI: 10.1093/gbe/evw243] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
LINE-1 (L1) retrotransposons are dynamic elements. They have the potential to cause great genomic change because of their ability to ‘jump’ around the genome and amplify themselves, resulting in the duplication and rearrangement of regulatory DNA. Active L1, in particular, are often thought of as tightly constrained, homologous and ubiquitous elements with well-characterized domain organization. For the past 30 years, model organisms have been used to define L1s as 6–8 kb sequences containing a 5′-UTR, two open reading frames working harmoniously in cis, and a 3′-UTR with a polyA tail. In this study, we demonstrate the remarkable and overlooked diversity of L1s via a comprehensive phylogenetic analysis of elements from over 500 species from widely divergent branches of the tree of life. The rapid and recent growth of L1 elements in mammalian species is juxtaposed against the diverse lineages found in other metazoans and plants. In fact, some of these previously unexplored mammalian species (e.g. snub-nosed monkey, minke whale) exhibit L1 retrotranspositional ‘hyperactivity’ far surpassing that of human or mouse. In contrast, non-mammalian L1s have become so varied that the current classification system seems to inadequately capture their structural characteristics. Our findings illustrate how both long-term inherited evolutionary patterns and random bursts of activity in individual species can significantly alter genomes, highlighting the importance of L1 dynamics in eukaryotes.
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Affiliation(s)
- Atma M Ivancevic
- School of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - R Daniel Kortschak
- School of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - Terry Bertozzi
- School of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia.,Evolutionary Biology Unit, South Australian Museum, Adelaide, South Australia, Australia
| | - David L Adelson
- School of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia
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Gallus S, Lammers F, Nilsson MA. When Genomics Is Not Enough: Experimental Evidence for a Decrease in LINE-1 Activity During the Evolution of Australian Marsupials. Genome Biol Evol 2016; 8:2406-12. [PMID: 27389686 PMCID: PMC5010896 DOI: 10.1093/gbe/evw159] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The autonomous transposable element LINE-1 is a highly abundant element that makes up between 15% and 20% of therian mammal genomes. Since their origin before the divergence of marsupials and placental mammals, LINE-1 elements have contributed actively to the genome landscape. A previous in silico screen of the Tasmanian devil genome revealed a lack of functional coding LINE-1 sequences. In this study we present the results of an in vitro analysis from a partial LINE-1 reverse transcriptase coding sequence in five marsupial species. Our experimental screen supports the in silico findings of the genome-wide degradation of LINE-1 sequences in the Tasmanian devil, and identifies a high frequency of degraded LINE-1 sequences in other Australian marsupials. The comparison between the experimentally obtained LINE-1 sequences and reference genome assemblies suggests that conclusions from in silico analyses of retrotransposition activity can be influenced by incomplete genome assemblies from short reads.
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Affiliation(s)
- Susanne Gallus
- Senckenberg Biodiversity and Climate Research Centre (BiK-F), Senckenberg Gesellschaft fuer Naturforschung, Senckenberg Anlage 25, Frankfurt, Germany Institute for Ecology, Evolution and Diversity, Faculty of Biological Sciences, Johann Wolfgang Goethe University Frankfurt Am Main, Max-von-Laue Straβe 9, 60438 Frankfurt am Main, Germany
| | - Fritjof Lammers
- Senckenberg Biodiversity and Climate Research Centre (BiK-F), Senckenberg Gesellschaft fuer Naturforschung, Senckenberg Anlage 25, Frankfurt, Germany Institute for Ecology, Evolution and Diversity, Faculty of Biological Sciences, Johann Wolfgang Goethe University Frankfurt Am Main, Max-von-Laue Straβe 9, 60438 Frankfurt am Main, Germany
| | - Maria Anna Nilsson
- Senckenberg Biodiversity and Climate Research Centre (BiK-F), Senckenberg Gesellschaft fuer Naturforschung, Senckenberg Anlage 25, Frankfurt, Germany
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18
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Canapa A, Barucca M, Biscotti MA, Forconi M, Olmo E. Transposons, Genome Size, and Evolutionary Insights in Animals. Cytogenet Genome Res 2016; 147:217-39. [PMID: 26967166 DOI: 10.1159/000444429] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/03/2015] [Indexed: 11/19/2022] Open
Abstract
The relationship between genome size and the percentage of transposons in 161 animal species evidenced that variations in genome size are linked to the amplification or the contraction of transposable elements. The activity of transposable elements could represent a response to environmental stressors. Indeed, although with different trends in protostomes and deuterostomes, comprehensive changes in genome size were recorded in concomitance with particular periods of evolutionary history or adaptations to specific environments. During evolution, genome size and the presence of transposable elements have influenced structural and functional parameters of genomes and cells. Changes of these parameters have had an impact on morphological and functional characteristics of the organism on which natural selection directly acts. Therefore, the current situation represents a balance between insertion and amplification of transposons and the mechanisms responsible for their deletion or for decreasing their activity. Among the latter, methylation and the silencing action of small RNAs likely represent the most frequent mechanisms.
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Affiliation(s)
- Adriana Canapa
- Dipartimento di Scienze della Vita e dell'Ambiente, Universitx00E0; Politecnica delle Marche, Ancona, Italy
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19
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Nilsson MA. The devil is in the details: Transposable element analysis of the Tasmanian devil genome. Mob Genet Elements 2015; 6:e1119926. [PMID: 27066301 DOI: 10.1080/2159256x.2015.1119926] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 11/10/2015] [Indexed: 10/22/2022] Open
Abstract
The third marsupial genome was sequenced from the Tasmanian devil (Sarcophilus harrisii), a species that currently is driven to extinction by a rare transmissible cancer. The transposable element (TE) landscape of the Tasmanian devil genome revealed that the main driver of retrotransposition the Long INterspersed Element 1 (LINE1) seem to have become inactivated during the past 12 million years. Strangely, the Short INterspersed Elements (SINE), that normally hijacks the LINE1 retrotransposition system, became inactive prior to LINE1 at around 30 million years ago. The SINE inactivation was in vitro verified in several species. Here I discuss that the apparent LINE1 inactivation might be caused by a genome assembly artifact. The repetitive fraction of any genome is highly complex to assemble and the observed problems are not unique to the Tasmanian devil genome.
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Affiliation(s)
- Maria A Nilsson
- Senckenberg Biodiversity and Climate Research Center, Senckenberg Gesellschaft für Naturforschung , Frankfurt am Main, Germany
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20
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Gallus S, Janke A, Kumar V, Nilsson MA. Disentangling the relationship of the Australian marsupial orders using retrotransposon and evolutionary network analyses. Genome Biol Evol 2015; 7:985-92. [PMID: 25786431 PMCID: PMC4419798 DOI: 10.1093/gbe/evv052] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The ancestors to the Australian marsupials entered Australia around 60 (54-72) Ma from Antarctica, and radiated into the four living orders Peramelemorphia, Dasyuromorphia, Diprotodontia, and Notoryctemorphia. The relationship between the four Australian marsupial orders has been a long-standing question, because different phylogenetic studies have not been able to consistently reconstruct the same topology. Initial in silico analysis of the Tasmanian devil genome and experimental screening in the seven marsupial orders revealed 20 informative transposable element insertions for resolving the inter- and intraordinal relationships of Australian and South American orders. However, the retrotransposon insertions support three conflicting topologies regarding Peramelemorphia, Dasyuromorphia, and Notoryctemorphia, indicating that the split between the three orders may be best understood as a network. This finding is supported by a phylogenetic reanalysis of nuclear gene sequences, using a consensus network approach that allows depicting hidden phylogenetic conflict, otherwise lost when forcing the data into a bifurcating tree. The consensus network analysis agrees with the transposable element analysis in that all possible topologies regarding Peramelemorphia, Dasyuromorphia, and Notoryctemorphia in a rooted four-taxon topology are equally well supported. In addition, retrotransposon insertion data support the South American order Didelphimorphia being the sistergroup to all other living marsupial orders. The four Australian orders originated within 3 Myr at the Cretaceous-Paleogene boundary. The rapid divergences left conflicting phylogenetic information in the genome possibly generated by incomplete lineage sorting or introgressive hybridization, leaving the relationship among Australian marsupial orders unresolvable as a bifurcating process millions of years later.
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Affiliation(s)
- Susanne Gallus
- Senckenberg Biodiversity and Climate Research Centre, Senckenberg Gesellschaft für Naturforschung, Senckenberganlage 25, 60325 Frankfurt am Main, Germany
| | - Axel Janke
- Senckenberg Biodiversity and Climate Research Centre, Senckenberg Gesellschaft für Naturforschung, Senckenberganlage 25, 60325 Frankfurt am Main, Germany Department of Biosciences, Institute for Ecology, Evolution & Diversity, Goethe University, Max-von-Laue-Str. 9, 60438 Frankfurt am Main, Germany
| | - Vikas Kumar
- Senckenberg Biodiversity and Climate Research Centre, Senckenberg Gesellschaft für Naturforschung, Senckenberganlage 25, 60325 Frankfurt am Main, Germany
| | - Maria A Nilsson
- Senckenberg Biodiversity and Climate Research Centre, Senckenberg Gesellschaft für Naturforschung, Senckenberganlage 25, 60325 Frankfurt am Main, Germany
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21
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Doucet AJ, Droc G, Siol O, Audoux J, Gilbert N. U6 snRNA Pseudogenes: Markers of Retrotransposition Dynamics in Mammals. Mol Biol Evol 2015; 32:1815-32. [PMID: 25761766 PMCID: PMC4476161 DOI: 10.1093/molbev/msv062] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Transposable elements comprise more than 45% of the human genome and long interspersed nuclear element 1 (LINE-1 or L1) is the only autonomous mobile element remaining active. Since its identification, it has been proposed that L1 contributes to the mobilization and amplification of other cellular RNAs and more recently, experimental demonstrations of this function has been described for many transcripts such as Alu, a nonautonomous mobile element, cellular mRNAs, or small noncoding RNAs. Detailed examination of the mobilization of various cellular RNAs revealed distinct pathways by which they could be recruited during retrotransposition; template choice or template switching. Here, by analyzing genomic structures and retrotransposition signatures associated with small nuclear RNA (snRNA) sequences, we identified distinct recruiting steps during the L1 retrotransposition cycle for the formation of snRNA-processed pseudogenes. Interestingly, some of the identified recruiting steps take place in the nucleus. Moreover, after comparison to other vertebrate genomes, we established that snRNA amplification by template switching is common to many LINE families from several LINE clades. Finally, we suggest that U6 snRNA copies can serve as markers of L1 retrotransposition dynamics in mammalian genomes.
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Affiliation(s)
- Aurélien J Doucet
- Institut de Génétique Humaine, CNRS, UPR 1142, Montpellier, France Institute for Research on Cancer and Aging, Nice (IRCAN), INSERM, U1081, CNRS UMR 7284, Nice, France
| | - Gaëtan Droc
- Institut de Génétique Humaine, CNRS, UPR 1142, Montpellier, France Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), UMR AGAP, Montpellier, France
| | - Oliver Siol
- Institut de Génétique Humaine, CNRS, UPR 1142, Montpellier, France Institut de Génétique Humaine, CNRS, UPR 1142, Montpellier, France
| | - Jérôme Audoux
- Institute for Regenerative Medicine and Biotherapy, INSERM, U1183, Montpellier, France
| | - Nicolas Gilbert
- Institut de Génétique Humaine, CNRS, UPR 1142, Montpellier, France Institute for Regenerative Medicine and Biotherapy, INSERM, U1183, Montpellier, France
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