1
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Gerdes P, Chan D, Lundberg M, Sanchez-Luque FJ, Bodea GO, Ewing AD, Faulkner GJ, Richardson SR. Locus-resolution analysis of L1 regulation and retrotransposition potential in mouse embryonic development. Genome Res 2023; 33:1465-1481. [PMID: 37798118 PMCID: PMC10620060 DOI: 10.1101/gr.278003.123] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 08/21/2023] [Indexed: 10/07/2023]
Abstract
Mice harbor ∼2800 intact copies of the retrotransposon Long Interspersed Element 1 (L1). The in vivo retrotransposition capacity of an L1 copy is defined by both its sequence integrity and epigenetic status, including DNA methylation of the monomeric units constituting young mouse L1 promoters. Locus-specific L1 methylation dynamics during development may therefore elucidate and explain spatiotemporal niches of endogenous retrotransposition but remain unresolved. Here, we interrogate the retrotransposition efficiency and epigenetic fate of source (donor) L1s, identified as mobile in vivo. We show that promoter monomer loss consistently attenuates the relative retrotransposition potential of their offspring (daughter) L1 insertions. We also observe that most donor/daughter L1 pairs are efficiently methylated upon differentiation in vivo and in vitro. We use Oxford Nanopore Technologies (ONT) long-read sequencing to resolve L1 methylation genome-wide and at individual L1 loci, revealing a distinctive "smile" pattern in methylation levels across the L1 promoter region. Using Pacific Biosciences (PacBio) SMRT sequencing of L1 5' RACE products, we then examine DNA methylation dynamics at the mouse L1 promoter in parallel with transcription start site (TSS) distribution at locus-specific resolution. Together, our results offer a novel perspective on the interplay between epigenetic repression, L1 evolution, and genome stability.
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Affiliation(s)
- Patricia Gerdes
- Mater Research Institute - University of Queensland, TRI Building, Woolloongabba, Queensland 4102, Australia
| | - Dorothy Chan
- Mater Research Institute - University of Queensland, TRI Building, Woolloongabba, Queensland 4102, Australia
| | - Mischa Lundberg
- Mater Research Institute - University of Queensland, TRI Building, Woolloongabba, Queensland 4102, Australia
- The University of Queensland Diamantina Institute, The University of Queensland, Woolloongabba, Queensland 4102, Australia
- Translational Bioinformatics, Commonwealth Scientific and Industrial Research Organisation, Sydney, New South Wales 2113, Australia
| | - Francisco J Sanchez-Luque
- Mater Research Institute - University of Queensland, TRI Building, Woolloongabba, Queensland 4102, Australia
- GENYO. Centre for Genomics and Oncological Research (Pfizer-University of Granada-Andalusian Regional Government), PTS Granada, 18016, Spain
- MRC Human Genetics Unit, Institute of Genetics and Cancer (IGC), University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, United Kingdom
| | - Gabriela O Bodea
- Mater Research Institute - University of Queensland, TRI Building, Woolloongabba, Queensland 4102, Australia
- Queensland Brain Institute, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Adam D Ewing
- Mater Research Institute - University of Queensland, TRI Building, Woolloongabba, Queensland 4102, Australia
| | - Geoffrey J Faulkner
- Mater Research Institute - University of Queensland, TRI Building, Woolloongabba, Queensland 4102, Australia;
- Queensland Brain Institute, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Sandra R Richardson
- Mater Research Institute - University of Queensland, TRI Building, Woolloongabba, Queensland 4102, Australia;
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2
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Haws SA, Yu D, Ye C, Wille CK, Nguyen LC, Krautkramer KA, Tomasiewicz JL, Yang SE, Miller BR, Liu WH, Igarashi K, Sridharan R, Tu BP, Cryns VL, Lamming DW, Denu JM. Methyl-Metabolite Depletion Elicits Adaptive Responses to Support Heterochromatin Stability and Epigenetic Persistence. Mol Cell 2020; 78:210-223.e8. [PMID: 32208170 PMCID: PMC7191556 DOI: 10.1016/j.molcel.2020.03.004] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 02/05/2020] [Accepted: 02/28/2020] [Indexed: 12/12/2022]
Abstract
S-adenosylmethionine (SAM) is the methyl-donor substrate for DNA and histone methyltransferases that regulate epigenetic states and subsequent gene expression. This metabolism-epigenome link sensitizes chromatin methylation to altered SAM abundance, yet the mechanisms that allow organisms to adapt and protect epigenetic information during life-experienced fluctuations in SAM availability are unknown. We identified a robust response to SAM depletion that is highlighted by preferential cytoplasmic and nuclear mono-methylation of H3 Lys 9 (H3K9) at the expense of broad losses in histone di- and tri-methylation. Under SAM-depleted conditions, H3K9 mono-methylation preserves heterochromatin stability and supports global epigenetic persistence upon metabolic recovery. This unique chromatin response was robust across the mouse lifespan and correlated with improved metabolic health, supporting a significant role for epigenetic adaptation to SAM depletion in vivo. Together, these studies provide evidence for an adaptive response that enables epigenetic persistence to metabolic stress.
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Affiliation(s)
- Spencer A Haws
- Department of Biomolecular Chemistry, SMPH, University of Wisconsin-Madison, Madison, WI 53706, USA; Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Deyang Yu
- William S. Middleton Memorial Veterans Hospital, Madison, WI 53705, USA; Department of Medicine, SMPH, University of Wisconsin-Madison, Madison, WI 53705, USA; Molecular & Environmental Toxicology Center, SMPH, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Cunqi Ye
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Coral K Wille
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Long C Nguyen
- Department of Biochemistry, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Kimberly A Krautkramer
- Department of Biomolecular Chemistry, SMPH, University of Wisconsin-Madison, Madison, WI 53706, USA; Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Jay L Tomasiewicz
- William S. Middleton Memorial Veterans Hospital, Madison, WI 53705, USA
| | - Shany E Yang
- William S. Middleton Memorial Veterans Hospital, Madison, WI 53705, USA; Department of Medicine, SMPH, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Blake R Miller
- William S. Middleton Memorial Veterans Hospital, Madison, WI 53705, USA; Department of Medicine, SMPH, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Wallace H Liu
- Department of Biomolecular Chemistry, SMPH, University of Wisconsin-Madison, Madison, WI 53706, USA; Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Kazuhiko Igarashi
- Department of Biochemistry, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan; Center for Regulatory Epigenome and Diseases, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Rupa Sridharan
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI 53715, USA; Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Benjamin P Tu
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Vincent L Cryns
- Department of Medicine, SMPH, University of Wisconsin-Madison, Madison, WI 53705, USA; Molecular & Environmental Toxicology Center, SMPH, University of Wisconsin-Madison, Madison, WI 53705, USA; University of Wisconsin Carbone Cancer Center, Madison, WI 53792, USA
| | - Dudley W Lamming
- William S. Middleton Memorial Veterans Hospital, Madison, WI 53705, USA; Department of Medicine, SMPH, University of Wisconsin-Madison, Madison, WI 53705, USA; Molecular & Environmental Toxicology Center, SMPH, University of Wisconsin-Madison, Madison, WI 53705, USA; University of Wisconsin Carbone Cancer Center, Madison, WI 53792, USA
| | - John M Denu
- Department of Biomolecular Chemistry, SMPH, University of Wisconsin-Madison, Madison, WI 53706, USA; Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI 53715, USA.
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3
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Restricted and non-essential redundancy of RNAi and piRNA pathways in mouse oocytes. PLoS Genet 2019; 15:e1008261. [PMID: 31860668 PMCID: PMC6944382 DOI: 10.1371/journal.pgen.1008261] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 01/06/2020] [Accepted: 12/02/2019] [Indexed: 11/19/2022] Open
Abstract
Germline genome defense evolves to recognize and suppress retrotransposons. One of defensive mechanisms is the PIWI-associated RNA (piRNA) pathway, which employs small RNAs for sequence-specific repression. The loss of the piRNA pathway in mice causes male sterility while females remain fertile. Unlike spermatogenic cells, mouse oocytes posses also RNA interference (RNAi), another small RNA pathway capable of retrotransposon suppression. To examine whether RNAi compensates the loss of the piRNA pathway, we produced a new RNAi pathway mutant DicerSOM and crossed it with a catalytically-dead mutant of Mili, an essential piRNA gene. Normal follicular and oocyte development in double mutants showed that RNAi does not suppress a strong ovarian piRNA knock-out phenotype. However, we observed redundant and non-redundant targeting of specific retrotransposon families illustrating stochasticity of recognition and targeting of invading retrotransposons. Intracisternal A Particle retrotransposon was mainly targeted by the piRNA pathway, MaLR and RLTR10 retrotransposons were targeted mainly by RNAi. Double mutants showed accumulations of LINE-1 retrotransposon transcripts. However, we did not find strong evidence for transcriptional activation and mobilization of retrotransposition competent LINE-1 elements suggesting that while both defense pathways are simultaneously expendable for ovarian oocyte development, yet another transcriptional silencing mechanism prevents mobilization of LINE-1 elements. Retrotransposons are mobile genomic parasites causing mutations. Germ cells need protection against retrotransposons to prevent heritable transmission of their new insertions. The piRNA pathway is an ancient germline defense system analogous to acquired immunity: once a retrotransposon jumps into a piRNA-producing locus, which provides a kind of a “genomic sensor” for actively transposing elements, it is recognized and suppressed. Remarkably, the murine piRNA pathway is essential for spermatogenesis but not oocyte development. In contrast, zebrafish lacking the piRNA pathway do not develop any germ cells. It was hypothesized that RNA interference pathway could rescue oocyte development in mice lacking the piRNA pathway. RNA interference also targets retrotransposons and is particularly enhanced in mouse oocytes. To test this hypothesis, we engineered mice lacking both pathways and observed that oocytes in these mice develop normally, which argues against the hypothesis. Furthermore, analysis of individual retrotransposon groups revealed that in specific cases the two pathways mutually compensate each other. However, this redundancy apparently evolved stochastically and is restricted to specific retrotransposon groups. Finally, our results indicate that there must be yet another layer of retrotransposon silencing in mouse oocytes, which prevents high retrotransposon activity in the absence of piRNA and RNA interference pathways.
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4
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Min B, Jeon K, Park JS, Kang Y. Demethylation and derepression of genomic retroelements in the skeletal muscles of aged mice. Aging Cell 2019; 18:e13042. [PMID: 31560164 PMCID: PMC6826136 DOI: 10.1111/acel.13042] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 08/07/2019] [Accepted: 08/30/2019] [Indexed: 12/13/2022] Open
Abstract
Changes in DNA methylation influence the aging process and contribute to aging phenotypes, but few studies have been conducted on DNA methylation changes in conjunction with skeletal muscle aging. We explored the DNA methylation changes in a variety of retroelement families throughout aging (at 2, 20, and 28 months of age) in murine skeletal muscles by methyl‐binding domain sequencing (MBD‐seq). The two following contrasting patterns were observed among the members of each repeat family in superaged mice: (a) hypermethylation in weakly methylated retroelement copies and (b) hypomethylation in copies with relatively stronger methylation levels, representing a pattern of “regression toward the mean” within a single retroelement family. Interestingly, these patterns depended on the sizes of the copies. While the majority of the elements showed a slight increase in methylation, the larger copies (>5 kb) displayed evident demethylation. All these changes were not observed in T cells. RNA sequencing revealed a global derepression of retroelements during the late phase of aging (between 20 and 28 months of age), which temporally coincided with retroelement demethylation. Following this methylation drift trend of “regression toward the mean,” aging tended to progressively lose the preexisting methylation differences and local patterns in the genomic regions that had been elaborately established during the early period of development.
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Affiliation(s)
- Byungkuk Min
- Development and Differentiation Research Center Korea Research Institute of Bioscience Biotechnology (KRIBB) Daejeon Korea
| | - Kyuheum Jeon
- Development and Differentiation Research Center Korea Research Institute of Bioscience Biotechnology (KRIBB) Daejeon Korea
- Department of Functional Genomics University of Science and Technology (UST) Daejeon Korea
| | - Jung Sun Park
- Development and Differentiation Research Center Korea Research Institute of Bioscience Biotechnology (KRIBB) Daejeon Korea
| | - Yong‐Kook Kang
- Development and Differentiation Research Center Korea Research Institute of Bioscience Biotechnology (KRIBB) Daejeon Korea
- Department of Functional Genomics University of Science and Technology (UST) Daejeon Korea
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5
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Basil P, Li Q, Sham PC, McAlonan GM. LINE1 and Mecp2 methylation of the adult striatum and prefrontal cortex exposed to prenatal immune activation. Data Brief 2019; 25:104003. [PMID: 31193946 PMCID: PMC6545381 DOI: 10.1016/j.dib.2019.104003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 03/27/2019] [Accepted: 05/09/2019] [Indexed: 01/05/2023] Open
Abstract
Prenatal exposure to infection and inflammation increases the risk of neurodevelopmental disorders such as schizophrenia and autism. The etiology could be partly through transgenerational and modifiable DNA methylation changes in the adult offspring's brain. This data descriptor presents a dataset of global DNA methylation (using LINE1 assay) and Mecp2 promoter methylation in adolescent and adult brain tissue of offspring exposed to prenatal immune activation on gestation day 9 and offspring of saline exposed mice. PCR based methylation assays using Sequenom EpiTYPER was used to quantify DNA methylation at promoter CpG methylation of Long Interspersed Elements-1 (LINE1 or L1) and Mecp2. The dataset also includes global DNA methylation and Mecp2 promoter methylation profile at 6 and 12 weeks following early dietary intervention with omega-3 (n-3) PUFA.
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Affiliation(s)
- Paul Basil
- Department of Psychiatry, The University of Hong Kong, Pokfulam, Hong Kong S.A.R., China.,Department of Molecular & Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Qi Li
- Department of Psychiatry, The University of Hong Kong, Pokfulam, Hong Kong S.A.R., China
| | - Pak-Chung Sham
- Department of Psychiatry, The University of Hong Kong, Pokfulam, Hong Kong S.A.R., China.,Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, King's College London, De Crespigny Park, Denmark Hill, London SE5 8AF, UK
| | - Grainne M McAlonan
- Department of Psychiatry, The University of Hong Kong, Pokfulam, Hong Kong S.A.R., China.,Centre for Genomic Sciences, The University of Hong Kong, Pokfulam, Hong Kong S.A.R., China
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6
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Simon M, Van Meter M, Ablaeva J, Ke Z, Gonzalez RS, Taguchi T, De Cecco M, Leonova KI, Kogan V, Helfand SL, Neretti N, Roichman A, Cohen HY, Meer MV, Gladyshev VN, Antoch MP, Gudkov AV, Sedivy JM, Seluanov A, Gorbunova V. LINE1 Derepression in Aged Wild-Type and SIRT6-Deficient Mice Drives Inflammation. Cell Metab 2019; 29:871-885.e5. [PMID: 30853213 PMCID: PMC6449196 DOI: 10.1016/j.cmet.2019.02.014] [Citation(s) in RCA: 264] [Impact Index Per Article: 52.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 11/02/2018] [Accepted: 02/22/2019] [Indexed: 01/07/2023]
Abstract
Mice deficient for SIRT6 exhibit a severely shortened lifespan, growth retardation, and highly elevated LINE1 (L1) activity. Here we report that SIRT6-deficient cells and tissues accumulate abundant cytoplasmic L1 cDNA, which triggers strong type I interferon response via activation of cGAS. Remarkably, nucleoside reverse-transcriptase inhibitors (NRTIs), which inhibit L1 retrotransposition, significantly improved health and lifespan of SIRT6 knockout mice and completely rescued type I interferon response. In tissue culture, inhibition of L1 with siRNA or NRTIs abrogated type I interferon response, in addition to a significant reduction of DNA damage markers. These results indicate that L1 activation contributes to the pathologies of SIRT6 knockout mice. Similarly, L1 transcription, cytoplasmic cDNA copy number, and type I interferons were elevated in the wild-type aged mice. As sterile inflammation is a hallmark of aging, we propose that modulating L1 activity may be an important strategy for attenuating age-related pathologies.
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Affiliation(s)
- Matthew Simon
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
| | - Michael Van Meter
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
| | - Julia Ablaeva
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
| | - Zhonghe Ke
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
| | - Raul S Gonzalez
- Department of Pathology, University of Rochester Medical Center, Rochester, NY 14627, USA
| | - Taketo Taguchi
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
| | - Marco De Cecco
- Institute for Translational Research, Ariel University, Ariel, Israel
| | - Katerina I Leonova
- Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, USA
| | - Valeria Kogan
- Institute for Translational Research, Ariel University, Ariel, Israel
| | - Stephen L Helfand
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA
| | - Nicola Neretti
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA
| | - Asael Roichman
- Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Haim Y Cohen
- Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Margarita V Meer
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Vadim N Gladyshev
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Marina P Antoch
- Department of Pharmacology and Therapeutics, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, USA
| | - Andrei V Gudkov
- Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, USA
| | - John M Sedivy
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA
| | - Andrei Seluanov
- Department of Biology, University of Rochester, Rochester, NY 14627, USA.
| | - Vera Gorbunova
- Department of Biology, University of Rochester, Rochester, NY 14627, USA.
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7
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Schauer SN, Carreira PE, Shukla R, Gerhardt DJ, Gerdes P, Sanchez-Luque FJ, Nicoli P, Kindlova M, Ghisletti S, Santos AD, Rapoud D, Samuel D, Faivre J, Ewing AD, Richardson SR, Faulkner GJ. L1 retrotransposition is a common feature of mammalian hepatocarcinogenesis. Genome Res 2018; 28:639-653. [PMID: 29643204 PMCID: PMC5932605 DOI: 10.1101/gr.226993.117] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 03/26/2018] [Indexed: 12/15/2022]
Abstract
The retrotransposon Long Interspersed Element 1 (LINE-1 or L1) is a continuing source of germline and somatic mutagenesis in mammals. Deregulated L1 activity is a hallmark of cancer, and L1 mutagenesis has been described in numerous human malignancies. We previously employed retrotransposon capture sequencing (RC-seq) to analyze hepatocellular carcinoma (HCC) samples from patients infected with hepatitis B or hepatitis C virus and identified L1 variants responsible for activating oncogenic pathways. Here, we have applied RC-seq and whole-genome sequencing (WGS) to an Abcb4 (Mdr2)-/- mouse model of hepatic carcinogenesis and demonstrated for the first time that L1 mobilization occurs in murine tumors. In 12 HCC nodules obtained from 10 animals, we validated four somatic L1 insertions by PCR and capillary sequencing, including TF subfamily elements, and one GF subfamily example. One of the TF insertions carried a 3' transduction, allowing us to identify its donor L1 and to demonstrate that this full-length TF element retained retrotransposition capacity in cultured cancer cells. Using RC-seq, we also identified eight tumor-specific L1 insertions from 25 HCC patients with a history of alcohol abuse. Finally, we used RC-seq and WGS to identify three tumor-specific L1 insertions among 10 intra-hepatic cholangiocarcinoma (ICC) patients, including one insertion traced to a donor L1 on Chromosome 22 known to be highly active in other cancers. This study reveals L1 mobilization as a common feature of hepatocarcinogenesis in mammals, demonstrating that the phenomenon is not restricted to human viral HCC etiologies and is encountered in murine liver tumors.
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Affiliation(s)
- Stephanie N Schauer
- Mater Research Institute-University of Queensland, Woolloongabba, QLD 4102, Australia
| | - Patricia E Carreira
- Mater Research Institute-University of Queensland, Woolloongabba, QLD 4102, Australia
| | - Ruchi Shukla
- Northern Institute for Cancer Research, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - Daniel J Gerhardt
- Mater Research Institute-University of Queensland, Woolloongabba, QLD 4102, Australia
- Invenra, Incorporated, Madison, Wisconsin 53719, USA
| | - Patricia Gerdes
- Mater Research Institute-University of Queensland, Woolloongabba, QLD 4102, Australia
| | - Francisco J Sanchez-Luque
- Mater Research Institute-University of Queensland, Woolloongabba, QLD 4102, Australia
- Department of Genomic Medicine, GENYO, Centre for Genomics and Oncological Research: Pfizer-University of Granada-Andalusian Regional Government, PTS Granada, 18016 Granada, Spain
| | - Paola Nicoli
- Department of Experimental Oncology, European Institute of Oncology, 20146 Milan, Italy
| | - Michaela Kindlova
- Mater Research Institute-University of Queensland, Woolloongabba, QLD 4102, Australia
| | | | - Alexandre Dos Santos
- INSERM, U1193, Paul-Brousse University Hospital, Hepatobiliary Centre, Villejuif 94800, France
- Université Paris-Sud, Faculté de Médecine, Villejuif 94800, France
| | - Delphine Rapoud
- INSERM, U1193, Paul-Brousse University Hospital, Hepatobiliary Centre, Villejuif 94800, France
- Université Paris-Sud, Faculté de Médecine, Villejuif 94800, France
| | - Didier Samuel
- INSERM, U1193, Paul-Brousse University Hospital, Hepatobiliary Centre, Villejuif 94800, France
- Université Paris-Sud, Faculté de Médecine, Villejuif 94800, France
| | - Jamila Faivre
- INSERM, U1193, Paul-Brousse University Hospital, Hepatobiliary Centre, Villejuif 94800, France
- Université Paris-Sud, Faculté de Médecine, Villejuif 94800, France
- Assistance Publique-Hôpitaux de Paris (AP-HP), Pôle de Biologie Médicale, Paul-Brousse University Hospital, Villejuif 94800, France
| | - Adam D Ewing
- Mater Research Institute-University of Queensland, Woolloongabba, QLD 4102, Australia
| | - Sandra R Richardson
- Mater Research Institute-University of Queensland, Woolloongabba, QLD 4102, Australia
| | - Geoffrey J Faulkner
- Mater Research Institute-University of Queensland, Woolloongabba, QLD 4102, Australia
- School of Biomedical Sciences, University of Queensland, Brisbane, QLD 4072, Australia
- Queensland Brain Institute, University of Queensland, Brisbane, QLD 4072, Australia
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8
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Xue AT, Ruggiero RP, Hickerson MJ, Boissinot S. Differential Effect of Selection against LINE Retrotransposons among Vertebrates Inferred from Whole-Genome Data and Demographic Modeling. Genome Biol Evol 2018; 10:1265-1281. [PMID: 29688421 PMCID: PMC5963298 DOI: 10.1093/gbe/evy083] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/20/2018] [Indexed: 12/30/2022] Open
Abstract
Variation in LINE composition is one of the major determinants for the substantial size and structural differences among vertebrate genomes. In particular, the larger genomes of mammals are characterized by hundreds of thousands of copies from a single LINE clade, L1, whereas nonmammalian vertebrates possess a much greater diversity of LINEs, yet with orders of magnitude less in copy number. It has been proposed that such variation in copy number among vertebrates is due to differential effect of LINE insertions on host fitness. To investigate LINE selection, we deployed a framework of demographic modeling, coalescent simulations, and probabilistic inference against population-level whole-genome data sets for four model species: one population each of threespine stickleback, green anole, and house mouse, as well as three human populations. Specifically, we inferred a null demographic background utilizing SNP data, which was then exploited to simulate a putative null distribution of summary statistics that was compared with LINE data. Subsequently, we applied the inferred null demographic model with an additional exponential size change parameter, coupled with model selection, to test for neutrality as well as estimate the strength of either negative or positive selection. We found a robust signal for purifying selection in anole and mouse, but a lack of clear evidence for selection in stickleback and human. Overall, we demonstrated LINE insertion dynamics that are not in accordance to a mammalian versus nonmammalian dichotomy, and instead the degree of existing LINE activity together with host-specific demographic history may be the main determinants of LINE abundance.
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Affiliation(s)
- Alexander T Xue
- Department of Biology: Subprogram in Ecology, Evolutionary Biology, and Behavior, City College and Graduate Center of City University of New York
- Human Genetics Institute of New Jersey and Department of Genetics, Rutgers University, Piscataway
| | - Robert P Ruggiero
- New York University Abu Dhabi, Saadiyat Island Campus, United Arab Emirates
| | - Michael J Hickerson
- Department of Biology: Subprogram in Ecology, Evolutionary Biology, and Behavior, City College and Graduate Center of City University of New York
- Division of Invertebrate Zoology, American Museum of Natural History, New York, New York
| | - Stéphane Boissinot
- New York University Abu Dhabi, Saadiyat Island Campus, United Arab Emirates
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9
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Richardson SR, Gerdes P, Gerhardt DJ, Sanchez-Luque FJ, Bodea GO, Muñoz-Lopez M, Jesuadian JS, Kempen MJHC, Carreira PE, Jeddeloh JA, Garcia-Perez JL, Kazazian HH, Ewing AD, Faulkner GJ. Heritable L1 retrotransposition in the mouse primordial germline and early embryo. Genome Res 2017; 27:1395-1405. [PMID: 28483779 PMCID: PMC5538555 DOI: 10.1101/gr.219022.116] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Accepted: 05/02/2017] [Indexed: 12/31/2022]
Abstract
LINE-1 (L1) retrotransposons are a noted source of genetic diversity and disease in mammals. To expand its genomic footprint, L1 must mobilize in cells that will contribute their genetic material to subsequent generations. Heritable L1 insertions may therefore arise in germ cells and in pluripotent embryonic cells, prior to germline specification, yet the frequency and predominant developmental timing of such events remain unclear. Here, we applied mouse retrotransposon capture sequencing (mRC-seq) and whole-genome sequencing (WGS) to pedigrees of C57BL/6J animals, and uncovered an L1 insertion rate of ≥1 event per eight births. We traced heritable L1 insertions to pluripotent embryonic cells and, strikingly, to early primordial germ cells (PGCs). New L1 insertions bore structural hallmarks of target-site primed reverse transcription (TPRT) and mobilized efficiently in a cultured cell retrotransposition assay. Together, our results highlight the rate and evolutionary impact of heritable L1 retrotransposition and reveal retrotransposition-mediated genomic diversification as a fundamental property of pluripotent embryonic cells in vivo.
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Affiliation(s)
- Sandra R Richardson
- Mater Research Institute-University of Queensland, Woolloongabba QLD 4102, Australia
| | - Patricia Gerdes
- Mater Research Institute-University of Queensland, Woolloongabba QLD 4102, Australia
| | - Daniel J Gerhardt
- Mater Research Institute-University of Queensland, Woolloongabba QLD 4102, Australia.,Invenra, Incorporated, Madison, Wisconsin 53719, USA
| | - Francisco J Sanchez-Luque
- Mater Research Institute-University of Queensland, Woolloongabba QLD 4102, Australia.,Department of Genomic Medicine, GENYO, Centre for Genomics and Oncological Research, Pfizer-University of Granada-Andalusian Regional Government, PTS Granada, 18016 Granada, Spain
| | - Gabriela-Oana Bodea
- Mater Research Institute-University of Queensland, Woolloongabba QLD 4102, Australia
| | - Martin Muñoz-Lopez
- Department of Genomic Medicine, GENYO, Centre for Genomics and Oncological Research, Pfizer-University of Granada-Andalusian Regional Government, PTS Granada, 18016 Granada, Spain
| | - J Samuel Jesuadian
- Mater Research Institute-University of Queensland, Woolloongabba QLD 4102, Australia
| | | | - Patricia E Carreira
- Mater Research Institute-University of Queensland, Woolloongabba QLD 4102, Australia
| | | | - Jose L Garcia-Perez
- Department of Genomic Medicine, GENYO, Centre for Genomics and Oncological Research, Pfizer-University of Granada-Andalusian Regional Government, PTS Granada, 18016 Granada, Spain.,Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, United Kingdom
| | - Haig H Kazazian
- Institute of Genetic Medicine and Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | - Adam D Ewing
- Mater Research Institute-University of Queensland, Woolloongabba QLD 4102, Australia
| | - Geoffrey J Faulkner
- Mater Research Institute-University of Queensland, Woolloongabba QLD 4102, Australia.,School of Biomedical Sciences.,Queensland Brain Institute, University of Queensland, Brisbane QLD 4072, Australia
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10
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Jachowicz JW, Torres-Padilla ME. LINEs in mice: features, families, and potential roles in early development. Chromosoma 2015; 125:29-39. [PMID: 25975894 DOI: 10.1007/s00412-015-0520-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 04/27/2015] [Accepted: 05/05/2015] [Indexed: 01/08/2023]
Abstract
Approximately half of the mammalian genome is composed of repetitive elements, including LINE-1 (L1) elements. Because of their potential ability to transpose and integrate into other regions of the genome, their activation represents a threat to genome stability. Molecular pathways have emerged to tightly regulate and repress their transcriptional activity, including DNA methylation, histone modifications, and RNA pathways. It has become evident that Line-L1 elements are evolutionary diverse and dedicated repression pathways have been recently uncovered that discriminate between evolutionary old and young elements, with RNA-directed silencing mechanisms playing a prominent role. During periods of epigenetic reprogramming in development, specific classes of repetitive elements are upregulated, presumably due to the loss of most heterochromatic marks in this process. While we have learnt a lot on the molecular mechanisms that regulate Line-L1 expression over the last years, it is still unclear whether reactivation of Line-L1 after fertilization serves a functional purpose or it is a simple side effect of reprogramming.
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Affiliation(s)
- Joanna W Jachowicz
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM U964, Université de Strasbourg, 67404, Illkirch, France
| | - Maria-Elena Torres-Padilla
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM U964, Université de Strasbourg, 67404, Illkirch, France.
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11
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Abstract
Today’s laboratory mouse, Mus musculus, has its origins as the ‘house mouse’ of North America and Europe. Beginning with mice bred by mouse fanciers, laboratory stocks (outbred) derived from M. musculus musculus from eastern Europe and M. m. domesticus from western Europe were developed into inbred strains. Since the mid-1980s, additional strains have been developed from Asian mice (M. m. castaneus from Thailand and M. m. molossinus from Japan) and from M. spretus which originated from the western Mediterranean region.
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12
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Prenatal maternal immune activation causes epigenetic differences in adolescent mouse brain. Transl Psychiatry 2014; 4:e434. [PMID: 25180573 PMCID: PMC4203009 DOI: 10.1038/tp.2014.80] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 07/02/2014] [Accepted: 07/14/2014] [Indexed: 12/17/2022] Open
Abstract
Epigenetic processes such as DNA methylation have been implicated in the pathophysiology of neurodevelopmental disorders including schizophrenia and autism. Epigenetic changes can be induced by environmental exposures such as inflammation. Here we tested the hypothesis that prenatal inflammation, a recognized risk factor for schizophrenia and related neurodevelopmental conditions, alters DNA methylation in key brain regions linked to schizophrenia, namely the dopamine rich striatum and endocrine regulatory centre, the hypothalamus. DNA methylation across highly repetitive elements (long interspersed element 1 (LINE1) and intracisternal A-particles (IAPs)) were used to proxy global DNA methylation. We also investigated the Mecp2 gene because it regulates transcription of LINE1 and has a known association with neurodevelopmental disorders. Brain tissue was harvested from 6 week old offspring of mice exposed to the viral analog PolyI:C or saline on gestation day 9. We used Sequenom EpiTYPER assay to quantitatively analyze differences in DNA methylation at IAPs, LINE1 elements and the promoter region of Mecp2. In the hypothalamus, prenatal exposure to PolyI:C caused significant global DNA hypomethylation (t=2.44, P=0.019, PolyI:C mean 69.67%, saline mean 70.19%), especially in females, and significant hypomethylation of the promoter region of Mecp2, (t=3.32, P=0.002; PolyI:C mean 26.57%, saline mean 34.63%). IAP methylation was unaltered. DNA methylation in the striatum was not significantly altered. This study provides the first experimental evidence that exposure to inflammation during prenatal life is associated with epigenetic changes, including Mecp2 promoter hypomethylation. This suggests that environmental and genetic risk factors associated with neurodevelopmental disorders may act upon similar pathways. This is important because epigenetic changes are potentially modifiable and their investigation may open new avenues for treatment.
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13
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Sookdeo A, Hepp CM, McClure MA, Boissinot S. Revisiting the evolution of mouse LINE-1 in the genomic era. Mob DNA 2013; 4:3. [PMID: 23286374 PMCID: PMC3600994 DOI: 10.1186/1759-8753-4-3] [Citation(s) in RCA: 121] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Accepted: 10/25/2012] [Indexed: 11/10/2022] Open
Abstract
Background LINE-1 (L1) is the dominant category of transposable elements in placental mammals. L1 has significantly affected the size and structure of all mammalian genomes and understanding the nature of the interactions between L1 and its mammalian host remains a question of crucial importance in comparative genomics. For this reason, much attention has been dedicated to the evolution of L1. Among the most studied elements is the mouse L1 which has been the subject of a number of studies in the 1980s and 1990s. These seminal studies, performed in the pre-genomic era when only a limited number of L1 sequences were available, have significantly improved our understanding of L1 evolution. Yet, no comprehensive study on the evolution of L1 in mouse has been performed since the completion of this genome sequence. Results Using the Genome Parsing Suite we performed the first evolutionary analysis of mouse L1 over the entire length of the element. This analysis indicates that the mouse L1 has recruited novel 5’UTR sequences more frequently than previously thought and that the simultaneous activity of non-homologous promoters seems to be one of the conditions for the co-existence of multiple L1 families or lineages. In addition the exchange of genetic information between L1 families is not limited to the 5’UTR as evidence of inter-family recombination was observed in ORF1, ORF2, and the 3’UTR. In contrast to the human L1, there was little evidence of rapid amino-acid replacement in the coiled-coil of ORF1, although this region is structurally unstable. We propose that the structural instability of the coiled-coil domain might be adaptive and that structural changes in this region are selectively equivalent to the rapid evolution at the amino-acid level reported in the human lineage. Conclusions The pattern of evolution of L1 in mouse shows some similarity with human suggesting that the nature of the interactions between L1 and its host might be similar in these two species. Yet, some notable differences, particularly in the evolution of ORF1, suggest that the molecular mechanisms involved in host-L1 interactions might be different in these two species.
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Affiliation(s)
- Akash Sookdeo
- Department of Biology, Queens College, the City University of New York, 65-30 Kissena Boulevard, Flushing, NY 11367-1597, USA.
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14
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Platt II RN, Ray DA. A non-LTR retroelement extinction in Spermophilus tridecemlineatus. Gene 2012; 500:47-53. [DOI: 10.1016/j.gene.2012.03.051] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Revised: 03/08/2012] [Accepted: 03/09/2012] [Indexed: 10/28/2022]
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15
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Montoya-Durango DE, Ramos KS. HPV E7 viral oncoprotein disrupts transcriptional regulation of L1Md retrotransposon. FEBS Lett 2011; 586:102-6. [PMID: 22172279 DOI: 10.1016/j.febslet.2011.12.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2011] [Revised: 11/29/2011] [Accepted: 12/02/2011] [Indexed: 01/01/2023]
Abstract
Murine L1Md-A5 retrotransposon is a redox-inducible element regulated by Nrf-2/JunD and E2F/Rb-binding sites within its promoter (5'-UTR). Because the human papillomavirus (HPV) oncoprotein E7 interacts with retinoblastoma (pRb) and members of the AP1 family, studies were conducted to examine functional interactions between HPV E7, pRb, and histone deacetylase 2 (HDAC2) in the regulation of L1Md-A5. Using a transient heterologous transcription system we found that HPV E7 alone, or in combination with HDAC2, disrupted pRb-mediated L1MdA-5 transactivation. HPV E7 also ablated the transcriptional response of L1Md-A5 to genotoxic stress, but did not interfere with basal activity. We conclude that HPV E7 associates with proteins involved in the assembly of macromolecular complexes that regulate antioxidant and E2F/Rb sites within L1MdA-5 to regulate biological activity.
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Affiliation(s)
- Diego E Montoya-Durango
- Department of Biochemistry and Molecular Biology and Center for Genetics and Molecular Medicine, School of Medicine, University of Louisville, Louisville, KY 40202, USA
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16
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Lukic S, Chen K. Human piRNAs are under selection in Africans and repress transposable elements. Mol Biol Evol 2011; 28:3061-7. [PMID: 21613236 PMCID: PMC3199439 DOI: 10.1093/molbev/msr141] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Piwi-interacting RNAs (piRNAs) are a recently discovered class of 24- to 30-nt noncoding RNAs whose best-understood function is to repress transposable elements (TEs) in animal germ lines. In humans, TE-derived sequences comprise ∼45% of the genome and there are several active TE families, including LINE-1 and Alu elements, which are a significant source of de novo mutations and intrapopulation variability. In the “ping-pong model,” piRNAs are thought to alternatively cleave sense and antisense TE transcripts in a positive feedback loop. Because piRNAs are poorly conserved between closely related species, including human and chimpanzee, we took a population genomics approach to study piRNA function and evolution. We found strong statistical evidence that piRNA sequences are under selective constraint in African populations. We then mapped the piRNA sequences to human TE sequences and found strong correlations between the age of each LINE-1 and Alu subfamily and the number of piRNAs mapping to the subfamily. This result supports the idea that piRNAs function as repressors of TEs in humans. Finally, we observed a significant depletion of piRNA matches in the reverse transcriptase region of the consensus human LINE-1 element but not of the consensus mouse LINE-1 element. This result suggests that reverse transcriptase might have an endogenous role specific to humans. Overall, our results elucidate the function and evolution of piRNAs in humans and highlight the utility of population genomics analysis for studying this rapidly evolving genetic system.
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Affiliation(s)
- Sergio Lukic
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
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17
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Johnsen JM, Levy GG, Westrick RJ, Tucker PK, Ginsburg D. The endothelial-specific regulatory mutation, Mvwf1, is a common mouse founder allele. Mamm Genome 2008; 19:32-40. [PMID: 18188647 PMCID: PMC2226002 DOI: 10.1007/s00335-007-9079-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2007] [Accepted: 10/05/2007] [Indexed: 11/28/2022]
Abstract
Mvwf1 is a cis-regulatory mutation previously identified in the RIIIS/J mouse strain that causes a unique tissue-specific switch in the expression of an N-acetylgalactosaminyltransferase, B4GALNT2, from intestinal epithelium to vascular endothelium. Vascular B4galnt2 expression results in aberrant glycosylation of von Willebrand Factor (VWF) and accelerated VWF clearance from plasma. We now report that 13 inbred mouse strains share the Mvwf1 tissue-specific switch and low VWF phenotype, including five wild-derived strains. Genomic sequencing identified a highly conserved 97-kb Mvwf1 haplotype block shared by these strains that encompasses a 30-kb region of high nucleotide sequence divergence from C57BL6/J flanking B4galnt2 exon 1. The analysis of a series of bacterial artificial chromosome (BAC) transgenes containing B4galnt2 derived from the RIIIS/J or C57BL6/J inbred mouse strains demonstrates that the corresponding sequences are sufficient to confer the vessel (RIIIS/J) or intestine (C57BL6/J)-specific expression patterns. Taken together, our data suggest that the region responsible for the Mvwf1 regulatory switch lies within an approximately 30-kb genomic interval upstream of the B4galnt2 gene. The observation that Mvwf1 is present in multiple wild-derived strains suggests that this locus may be retained in wild mouse populations due to positive selection. Similar selective pressures could contribute to the high prevalence of von Willebrand disease in humans.
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Affiliation(s)
- Jill M. Johnsen
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan 48109-2216 USA
| | - Gallia G. Levy
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, Michigan 48109-2216 USA
| | - Randal J. Westrick
- Department of Human Genetics, University of Michigan, Ann Arbor, Michigan 48109-2216 USA
| | - Priscilla K. Tucker
- Department of Ecology and Evolutionary Biology, and the Museum of Zoology, University of Michigan, Ann Arbor, Michigan 48109-2216 USA
| | - David Ginsburg
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan 48109-2216 USA
- Department of Human Genetics, University of Michigan, Ann Arbor, Michigan 48109-2216 USA
- Howard Hughes Medical Institute, University of Michigan, 210 Washtenaw Avenue, Life Sciences Institute, Room 5028, Ann Arbor, Michigan 48109-2216 USA
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18
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Nishihara H, Hasegawa M, Okada N. Pegasoferae, an unexpected mammalian clade revealed by tracking ancient retroposon insertions. Proc Natl Acad Sci U S A 2006; 103:9929-34. [PMID: 16785431 PMCID: PMC1479866 DOI: 10.1073/pnas.0603797103] [Citation(s) in RCA: 170] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2006] [Indexed: 11/18/2022] Open
Abstract
Despite the recent large-scale efforts dedicated to comprehensive phylogenetic analyses using mitochondrial and nuclear DNA sequences, several relationships among mammalian orders remain controversial. Here, we present an extensive application of retroposon (L1) insertion analysis to the phylogenetic relationships among almost all mammalian orders. In addition to demonstrating the validity of Glires, Euarchontoglires, Laurasiatheria, and Boreoeutheria, we demonstrate an interordinal clade that links Chiroptera, Carnivora, and Perissodactyla within Laurasiatheria. Re-examination of a large DNA sequence data set yielded results consistent with our conclusion. We propose a superordinal name "Pegasoferae" for this clade of Chiroptera + Perissodactyla + Carnivora + Pholidota. The presence of a single incongruent L1 locus generates a tree in which the group of Carnivora + Perissodactyla associates with Cetartiodactyla but not with Chiroptera. This result suggests that incomplete lineage sorting of an ancestral dimorphism occurred with regard to the presence or absence of retroposon alleles in a common ancestor of Scrotifera (Pegasoferae + Cetartiodactyla), which was followed by rapid divergence into the extant orders over an evolutionarily short period. Accordingly, Euungulata (Cetartiodactyla + Perissodactyla) and Fereuungulata (Carnivora + Pholidota + Perissodactyla + Cetartiodactyla) cannot be validated as natural groups. The interordinal mammalian relationships presented here provide a cornerstone for future studies in the reconstruction of mammalian classifications, including extinct species, on evolution of large genomic sequences and structure, and in developmental analysis of morphological diversification.
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Affiliation(s)
- Hidenori Nishihara
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama 226-8501, Japan
| | - Masami Hasegawa
- Department of Statistical Modeling, Institute of Statistical Mathematics, Tokyo 106-8569, Japan
- Department of Biosystems Science, Graduate University for Advanced Studies, Hayama, Kanagawa 240-0193, Japan; and
| | - Norihiro Okada
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama 226-8501, Japan
- Division of Speciation, National Institute of Basic Biology, Okazaki 444-8585, Japan
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19
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Scott LA, Kuroiwa A, Matsuda Y, Wichman HA. X accumulation of LINE-1 retrotransposons in Tokudaia osimensis, a spiny rat with the karyotype XO. Cytogenet Genome Res 2006; 112:261-9. [PMID: 16484782 DOI: 10.1159/000089880] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2005] [Accepted: 07/25/2005] [Indexed: 01/02/2023] Open
Abstract
The observation that LINE-1 transposable elements are enriched on the X in comparison to the autosomes led to the hypothesis that LINE-1s play a role in X chromosome inactivation. If this hypothesis is correct, loss of LINE-1 activity would be expected to result in species extinction or in an alternate pathway of dosage compensation. One such alternative pathway would be to evolve a karyotype that does not require dosage compensation between the sexes. Two of the three extant species of the Ryukyu spiny rat Tokudaia have such a karyotype; both males and females are XO. We asked whether this karyotype arose due to loss of LINE-1 activity and thus the loss of a putative component in the X inactivation pathway. Although XO Tokudaia has no need for dosage compensation, LINE-1s have been recently active in Tokudaia osimensis and show higher density on the lone X than on the autosomes.
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Affiliation(s)
- L A Scott
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844-3051, USA
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20
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Grahn RA, Rinehart TA, Cantrell MA, Wichman HA. Extinction of LINE-1 activity coincident with a major mammalian radiation in rodents. Cytogenet Genome Res 2005; 110:407-15. [PMID: 16093693 DOI: 10.1159/000084973] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2004] [Accepted: 04/07/2004] [Indexed: 11/19/2022] Open
Abstract
LINE-1 transposable elements (L1s) are ubiquitous in mammals and are thought to have remained active since before the mammalian radiation. Only one L1 extinction event, in South American rodents in the genus Oryzomys, has been convincingly demonstrated. Here we examine the phylogenetic limits and evolutionary tempo of that extinction event by characterizing L1s in related rodents. Fourteen genera from five tribes within the Sigmodontinae subfamily were examined. Only the Sigmodontini, the most basal tribe in this group, demonstrate recent L1 activity. The Oryzomyini, Akodontini, Phyllotini, and Thomasomyini contain only L1s that appear to have inserted long ago; their L1s lack open reading frames, have mutations at conserved amino acid residues, and show numerous private mutations. They also lack restriction site-defined L1 subfamilies specific to any species, genus or tribe examined, and fail to form monophyletic species, genus or tribal L1 clusters. We determine here that this L1 extinction event occurred roughly 8.8 million years ago, near the divergence of Sigmodon from the remaining Sigmodontinae species. These species appear to be ideal model organisms for studying the impact of L1 inactivity on mammalian genomes.
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Affiliation(s)
- R A Grahn
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844-3051, USA
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21
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Fryxell KJ, Moon WJ. CpG mutation rates in the human genome are highly dependent on local GC content. Mol Biol Evol 2004; 22:650-8. [PMID: 15537806 DOI: 10.1093/molbev/msi043] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
CpG dinucleotides mutate at a high rate because cytosine is vulnerable to deamination, cytosines in CpG dinucleotides are often methylated, and deamination of 5-methylcytosine (5mC) produces thymidine. Previous experiments have shown that DNA melting is the rate-limiting step in cytosine deamination. Here we show, through the analysis of human single-nucleotide polymorphisms (SNPs), that the mutation rate produced by 5mC deamination is highly dependent on local GC content. In fact, linear regression analysis showed that the log(10) of the 5mC mutation rates (inferred from SNP frequencies) had slopes of -3 when graphed with respect to the GC content of neighboring sequences. This is the ideal slope that would be expected if the correlation between CpG underrepresentation and GC content had been solely caused by DNA melting. Moreover, this same result was obtained regardless of the SNP locations (all SNPs versus only SNPs in noncoding intergenic regions, excluding CpG islands) and regardless of the lengths over which GC content was calculated (SNP sequences with a modal length of 564 bp versus genomic contigs with a modal length of 163 kb). Several alternative interpretations are discussed.
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Affiliation(s)
- Karl J Fryxell
- Center for Biomedical Genomics and Informatics, Department of Molecular and Microbiology, George Mason University, Manassas, Virginia, USA.
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22
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Serwer P, Hayes SJ, Zaman S, Lieman K, Rolando M, Hardies SC. Improved isolation of undersampled bacteriophages: finding of distant terminase genes. Virology 2004; 329:412-24. [PMID: 15518819 DOI: 10.1016/j.virol.2004.08.021] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2004] [Revised: 08/16/2004] [Accepted: 08/20/2004] [Indexed: 11/22/2022]
Abstract
Isolation and characterization of new environmental bacteriophages are performed for (1) analyzing microbial evolution and ecology and (2) delivering biological therapy. The sampling of environmental bacteriophages appears, however, to be limited by the procedure (usually liquid enrichment culture) used to propagate them. An alternative, less competitive procedure is developed here for the purpose of isolating new bacteriophages. This procedure involves extraction directly into and then propagation in a dilute agarose gel. Adaptations of this procedure are used to avoid repeated isolation of the same bacteriophage. Some newly isolated bacteriophages grow so poorly that they appear inaccessible to liquid enrichment culture. Four comparatively high titer bacteriophages were isolated and characterized by a genomic sequence survey. Some had genomes with extremely distant relationships to those of other bacteriophages, based on a tree built from the large terminase genes. These methods find novel genomes by rapidly isolating and screening diverse bacteriophages.
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Affiliation(s)
- Philip Serwer
- Department of Biochemistry, The University of Texas Health Science Center, San Antonio, TX 78229-3900, USA.
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23
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Munclinger P, Boursot P, Dod B. B1 insertions as easy markers for mouse population studies. Mamm Genome 2003; 14:359-66. [PMID: 12879357 DOI: 10.1007/s00335-002-3065-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2002] [Accepted: 02/05/2003] [Indexed: 10/26/2022]
Abstract
Few simple, easy-to-score PCR markers are available for studying genetic variation in wild mice populations belonging to Mus musculus at the population and subspecific levels. In this study, we show the abundant B1 family of short interspersed DNA elements (SINEs) is a very promising source of such markers. Thirteen B1 sequences from different regions of the genome were retrieved on the basis of their high degree of homology to a mouse consensus sequence, and the presence of these elements was screened for in wild derived mice representing M. spretus, macedonicus and spicilegus and the different subspecies of M. musculus. At five of these loci, varying degrees of insertion polymorphism were found in M. m. domesticus mice. These insertions were almost totally absent in the mice representing the other subspecies and species. Six other B1 elements were fixed in all the Mus species tested. At these loci, polymorphism associated with three restriction sites in the B1 consensus sequence was found in M. musculus. Most of these polymorphisms appear to be ancestral as they are shared by at least one of the other Mus species tested. Both insertion and restriction polymorphism revealed differences between five inbred laboratory strains considered to be of mainly domesticus origin, and at the six restriction loci a surprising number of these strains carried restriction variants that were either not found or very infrequent in domesticus. This suggests that in this particular group of loci, alleles of far Eastern origin are more frequent than expected.
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Affiliation(s)
- Pavel Munclinger
- Biodiversity Research Group, Department of Zoology, Faculty of Science, Charles University, Vinicná 7, CZ 128 44 Praha 2, Czech Republic.
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24
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Kolosha VO, Martin SL. High-affinity, non-sequence-specific RNA binding by the open reading frame 1 (ORF1) protein from long interspersed nuclear element 1 (LINE-1). J Biol Chem 2003; 278:8112-7. [PMID: 12506113 DOI: 10.1074/jbc.m210487200] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Long interspersed nuclear element 1 (LINE-1 or L1) is an interspersed repeated DNA found in mammalian genomes. L1 achieved its high copy number by retrotransposition, a process that requires the two L1-encoded proteins, ORF1p and ORF2p. The role of ORF1p in the retrotransposition cycle is incompletely understood, but it is known to bind single-stranded nucleic acids and act as a nucleic acid chaperone. This study assesses the nature and specificity of the interaction of ORF1p with RNA. Results of coimmunoprecipitation experiments demonstrate that ORF1p preferentially binds a single T1 nuclease digestion product of 38 nucleotides (nt) within the full-length mouse L1 transcript. The 38-nt fragment is localized within L1 RNA and found to be sufficient for binding by ORF1p but not necessary, because its complement is also efficiently coimmunoprecipitated, as are all sequences 38 nt or longer. Results of nitrocellulose filter-binding assays demonstrate that the binding of ORF1p to RNA does not require divalent cations but is sensitive to the concentration of monovalent cation. Both sense and antisense transcripts bind with apparent K(D)s in the low nanomolar range. The results of both types of assay unambiguously support the conclusion that purified ORF1p from mouse L1 is a high-affinity, non-sequence-specific RNA binding protein.
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Affiliation(s)
- Vladimir O Kolosha
- Department of Cellular and Structural Biology and Program in Molecular Biology, University of Colorado School of Medicine, Denver 80262, USA
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Waterston RH, Lindblad-Toh K, Birney E, Rogers J, Abril JF, Agarwal P, Agarwala R, Ainscough R, Alexandersson M, An P, Antonarakis SE, Attwood J, Baertsch R, Bailey J, Barlow K, Beck S, Berry E, Birren B, Bloom T, Bork P, Botcherby M, Bray N, Brent MR, Brown DG, Brown SD, Bult C, Burton J, Butler J, Campbell RD, Carninci P, Cawley S, Chiaromonte F, Chinwalla AT, Church DM, Clamp M, Clee C, Collins FS, Cook LL, Copley RR, Coulson A, Couronne O, Cuff J, Curwen V, Cutts T, Daly M, David R, Davies J, Delehaunty KD, Deri J, Dermitzakis ET, Dewey C, Dickens NJ, Diekhans M, Dodge S, Dubchak I, Dunn DM, Eddy SR, Elnitski L, Emes RD, Eswara P, Eyras E, Felsenfeld A, Fewell GA, Flicek P, Foley K, Frankel WN, Fulton LA, Fulton RS, Furey TS, Gage D, Gibbs RA, Glusman G, Gnerre S, Goldman N, Goodstadt L, Grafham D, Graves TA, Green ED, Gregory S, Guigó R, Guyer M, Hardison RC, Haussler D, Hayashizaki Y, Hillier LW, Hinrichs A, Hlavina W, Holzer T, Hsu F, Hua A, Hubbard T, Hunt A, Jackson I, Jaffe DB, Johnson LS, Jones M, Jones TA, Joy A, Kamal M, Karlsson EK, Karolchik D, Kasprzyk A, Kawai J, Keibler E, Kells C, Kent WJ, Kirby A, Kolbe DL, Korf I, Kucherlapati RS, Kulbokas EJ, Kulp D, Landers T, Leger JP, Leonard S, Letunic I, Levine R, Li J, Li M, Lloyd C, Lucas S, Ma B, Maglott DR, Mardis ER, Matthews L, Mauceli E, Mayer JH, McCarthy M, McCombie WR, McLaren S, McLay K, McPherson JD, Meldrim J, Meredith B, Mesirov JP, Miller W, Miner TL, Mongin E, Montgomery KT, Morgan M, Mott R, Mullikin JC, Muzny DM, Nash WE, Nelson JO, Nhan MN, Nicol R, Ning Z, Nusbaum C, O'Connor MJ, Okazaki Y, Oliver K, Overton-Larty E, Pachter L, Parra G, Pepin KH, Peterson J, Pevzner P, Plumb R, Pohl CS, Poliakov A, Ponce TC, Ponting CP, Potter S, Quail M, Reymond A, Roe BA, Roskin KM, Rubin EM, Rust AG, Santos R, Sapojnikov V, Schultz B, Schultz J, Schwartz MS, Schwartz S, Scott C, Seaman S, Searle S, Sharpe T, Sheridan A, Shownkeen R, Sims S, Singer JB, Slater G, Smit A, Smith DR, Spencer B, Stabenau A, Stange-Thomann N, Sugnet C, Suyama M, Tesler G, Thompson J, Torrents D, Trevaskis E, Tromp J, Ucla C, Ureta-Vidal A, Vinson JP, Von Niederhausern AC, Wade CM, Wall M, Weber RJ, Weiss RB, Wendl MC, West AP, Wetterstrand K, Wheeler R, Whelan S, Wierzbowski J, Willey D, Williams S, Wilson RK, Winter E, Worley KC, Wyman D, Yang S, Yang SP, Zdobnov EM, Zody MC, Lander ES. Initial sequencing and comparative analysis of the mouse genome. Nature 2002; 420:520-62. [PMID: 12466850 DOI: 10.1038/nature01262] [Citation(s) in RCA: 4832] [Impact Index Per Article: 219.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2002] [Accepted: 10/31/2002] [Indexed: 12/18/2022]
Abstract
The sequence of the mouse genome is a key informational tool for understanding the contents of the human genome and a key experimental tool for biomedical research. Here, we report the results of an international collaboration to produce a high-quality draft sequence of the mouse genome. We also present an initial comparative analysis of the mouse and human genomes, describing some of the insights that can be gleaned from the two sequences. We discuss topics including the analysis of the evolutionary forces shaping the size, structure and sequence of the genomes; the conservation of large-scale synteny across most of the genomes; the much lower extent of sequence orthology covering less than half of the genomes; the proportions of the genomes under selection; the number of protein-coding genes; the expansion of gene families related to reproduction and immunity; the evolution of proteins; and the identification of intraspecies polymorphism.
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MESH Headings
- Animals
- Base Composition
- Chromosomes, Mammalian/genetics
- Conserved Sequence/genetics
- CpG Islands/genetics
- Evolution, Molecular
- Gene Expression Regulation
- Genes/genetics
- Genetic Variation/genetics
- Genome
- Genome, Human
- Genomics
- Humans
- Mice/classification
- Mice/genetics
- Mice, Knockout
- Mice, Transgenic
- Models, Animal
- Multigene Family/genetics
- Mutagenesis
- Neoplasms/genetics
- Physical Chromosome Mapping
- Proteome/genetics
- Pseudogenes/genetics
- Quantitative Trait Loci/genetics
- RNA, Untranslated/genetics
- Repetitive Sequences, Nucleic Acid/genetics
- Selection, Genetic
- Sequence Analysis, DNA
- Sex Chromosomes/genetics
- Species Specificity
- Synteny
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Boison D, Scheurer L, Zumsteg V, Rülicke T, Litynski P, Fowler B, Brandner S, Mohler H. Neonatal hepatic steatosis by disruption of the adenosine kinase gene. Proc Natl Acad Sci U S A 2002; 99:6985-90. [PMID: 11997462 PMCID: PMC124515 DOI: 10.1073/pnas.092642899] [Citation(s) in RCA: 164] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Neonatal hepatic steatosis (OMIM 228100) is a fatal condition of unknown etiology characterized by a pale and yellow liver and early postnatal mortality. In the present study, a deficit in adenosine-dependent metabolism is proposed as a causative factor. Physiologically, adenosine is efficiently metabolized to AMP by adenosine kinase (ADK), an enzyme highly expressed in liver. ADK not only ensures normal adenine nucleotide levels but also is essential for maintaining S-adenosylmethionine-dependent transmethylation processes, where adenosine, an obligatory product, has to be constantly removed. Homozygous Adk(-/-) mutants developed normally during embryogenesis. However, within 4 days after birth they displayed microvesicular hepatic steatosis and died within 14 days with fatty liver. Adenine nucleotides were decreased and S-adenosylhomocysteine, a potent inhibitor of transmethylation reactions, was increased in the mutant liver. Thus, a deficiency in adenosine metabolism is identified as a powerful contributor to the development of neonatal hepatic steatosis, providing a model for the rapid development of postnatally lethal fatty liver.
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Affiliation(s)
- Detlev Boison
- Institute of Pharmacology and Toxicology, University of Zurich, CH-8057 Zurich, Switzerland.
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Karn RC, Orth A, Bonhomme F, Boursot P. The complex history of a gene proposed to participate in a sexual isolation mechanism in house mice. Mol Biol Evol 2002; 19:462-71. [PMID: 11919288 DOI: 10.1093/oxfordjournals.molbev.a004102] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Previous behavioral experiments showed that mouse salivary androgen-binding protein (ABP) was involved in interindividual recognition and might play a role in sexual isolation between house mouse (Mus musculus) subspecies. The pattern of evolution of Abpa, the gene for the alpha subunit of ABP, was found to be consistent with this hypothesis. Abpa apparently diverged rapidly between species and subspecies with a large excess of nonsynonymous substitutions, a lack of exon polymorphism within each of the three subspecies, and a lack of intron polymorphism in the one subspecies studied (M. musculus domesticus). Here we characterized the intron and exon sequence variations of this gene in house mouse populations from central Eurasia, a region yet unsampled and thought to be close to the cradle of the radiation of the subspecies. We also determined the intron and exon sequences in seven other species of the genus Mus. We confirmed the general pattern of rapid evolution by essentially nonsynonymous substitutions, both inter- and intraspecifically, supporting the idea that Darwinian selection has driven the evolution of this gene. We also observed a uniform intron sequence in five samples of M. musculus musculus, suggesting that a selective sweep might have occurred for that allele. In contrast to previous results, however, we found extensive intron and exon polymorphism in some house mouse populations from central Eurasia. We also found evidence for secondary admixture of the subspecies-specific alleles in regions of transition between the subspecies in central Eurasia. Furthermore, an abnormal intron phylogeny suggested that interspecific exchanges had occurred between the house mouse subspecies and three other Palearctic species. These observations appear to be at variance with the simple hypothesis that Abpa is involved in reproductive isolation. Although we do not rule out a role in recognition, the situation appears to be more complex than previously thought. Thus the selective mechanism behind the evolution of Abpa remains to be resolved, and we suggest that it may have changed during the recent colonization history of the house mouse.
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Affiliation(s)
- Robert C Karn
- Department of Biological Sciences, Butler University, 4600 Sunset Avenue, Indianapolis, IN 46208, USA.
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Orth A, Belkhir K, Britton-Davidian J, Boursot P, Benazzou T, Bonhomme F. [Natural hybridization between 2 sympatric species of mice, Mus musculus domesticus L. and Mus spretus Lataste]. C R Biol 2002; 325:89-97. [PMID: 11980180 DOI: 10.1016/s1631-0691(02)01413-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Using protein loci and DNA markers, we show by a multilocus genetic analysis that certain populations of the two sympatric mouse species Mus musculus domesticus and Mus spretus show clear signs of partial introgression. Given the sterility of F1 males and the known partial genetic incompatibilities between the genomes of the two species, our finding does not invalidate the biological species complex, but allows to think that very limited genetic exchanges remain possible even long after the divergence of taxa. This may have some consequences on the dynamics of certain kinds of invasive or advantageous DNAs like transposable elements or pathogen resistance genes.
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Affiliation(s)
- Annie Orth
- Laboratoire génome populations interactions, UMR 5000 CNRS-université Montpellier-II, 34095 Montpellier, France
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Goodier JL, Ostertag EM, Du K, Kazazian HH. A novel active L1 retrotransposon subfamily in the mouse. Genome Res 2001; 11:1677-85. [PMID: 11591644 PMCID: PMC311137 DOI: 10.1101/gr.198301] [Citation(s) in RCA: 169] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Unlike human L1 retrotransposons, the 5' UTR of mouse L1 elements contains tandem repeats of approximately 200 bp in length called monomers. Multiple L1 subfamilies exist in the mouse which are distinguished by their monomer sequences. We previously described a young subfamily, called the T(F) subfamily, which contains approximately 1800 active elements among its 3000 full-length members. Here we characterize a novel subfamily of mouse L1 elements, G(F), which has unique monomer sequence and unusual patterns of monomer organization. A majority of these G(F) elements also have a unique length polymorphism in ORF1. Polymorphism analysis of G(F) elements in various mouse subspecies and laboratory strains revealed that, like T(F), the G(F) subfamily is young and expanding. About 1500 full-length G(F) elements exist in the diploid mouse genome and, based on the results of a cell culture assay, approximately 400 G(F) elements are potentially capable of retrotransposition. We also tested 14 A-type subfamily elements in the assay and estimate that about 900 active A elements may be present in the mouse genome. Thus, it is now known that there are three large active subfamilies of mouse L1s; T(F), A, and G(F), and that in total approximately 3000 full-length elements are potentially capable of active retrotransposition. This number is in great excess to the number of L1 elements thought to be active in the human genome.
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Affiliation(s)
- J L Goodier
- Department of Genetics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA.
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