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Kawase M, Ichiyanagi K. Mouse retrotransposons: sequence structure, evolutionary age, genomic distribution and function. Genes Genet Syst 2024; 98:337-351. [PMID: 37989301 DOI: 10.1266/ggs.23-00221] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2023] Open
Abstract
Retrotransposons are transposable elements that are transposed via transcription and reverse transcription. Their copies have accumulated in the genome of mammals, occupying approximately 40% of mammalian genomic mass. These copies are often involved in numerous phenomena, such as chromatin spatial organization, gene expression, development and disease, and have been recognized as a driving force in evolution. Different organisms have gained specific retrotransposon subfamilies and retrotransposed copies, such as hundreds of Mus-specific subfamilies with diverse sequences and genomic locations. Despite this complexity, basic information is still necessary for present-day genomic and epigenomic studies. Herein, we describe the characteristics of each subfamily of Mus-specific retrotransposons in terms of sequence structure, phylogenetic relationships, evolutionary age, and preference for A or B compartments of chromatin.
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Affiliation(s)
- Masaki Kawase
- Laboratory of Genome and Epigenome Dynamics, Department of Animal Sciences, Graduate School of Bioagricultural Sciences, Nagoya University
| | - Kenji Ichiyanagi
- Laboratory of Genome and Epigenome Dynamics, Department of Animal Sciences, Graduate School of Bioagricultural Sciences, Nagoya University
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2
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Osipovich AB, Dudek KD, Trinh LT, Kim LH, Shrestha S, Cartailler JP, Magnuson MA. ZFP92, a KRAB domain zinc finger protein enriched in pancreatic islets, binds to B1/Alu SINE transposable elements and regulates retroelements and genes. PLoS Genet 2023; 19:e1010729. [PMID: 37155670 PMCID: PMC10166502 DOI: 10.1371/journal.pgen.1010729] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 04/02/2023] [Indexed: 05/10/2023] Open
Abstract
Repressive KRAB domain-containing zinc-finger proteins (KRAB-ZFPs) are abundant in mammalian genomes and contribute both to the silencing of transposable elements (TEs) and to the regulation of developmental stage- and cell type-specific gene expression. Here we describe studies of zinc finger protein 92 (Zfp92), an X-linked KRAB-ZFP that is highly expressed in pancreatic islets of adult mice, by analyzing global Zfp92 knockout (KO) mice. Physiological, transcriptomic and genome-wide chromatin binding studies indicate that the principal function of ZFP92 in mice is to bind to and suppress the activity of B1/Alu type of SINE elements and modulate the activity of surrounding genomic entities. Deletion of Zfp92 leads to changes in expression of select LINE and LTR retroelements and genes located in the vicinity of ZFP92-bound chromatin. The absence of Zfp92 leads to altered expression of specific genes in islets, adipose and muscle that result in modest sex-specific alterations in blood glucose homeostasis, body mass and fat accumulation. In islets, Zfp92 influences blood glucose concentration in postnatal mice via transcriptional effects on Mafb, whereas in adipose and muscle, it regulates Acacb, a rate-limiting enzyme in fatty acid metabolism. In the absence of Zfp92, a novel TE-Capn11 fusion transcript is overexpressed in islets and several other tissues due to de-repression of an IAPez TE adjacent to ZFP92-bound SINE elements in intron 3 of the Capn11 gene. Together, these studies show that ZFP92 functions both to repress specific TEs and to regulate the transcription of specific genes in discrete tissues.
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Affiliation(s)
- Anna B. Osipovich
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States of America
- Center for Stem Cell Biology, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Karrie D. Dudek
- Center for Stem Cell Biology, Vanderbilt University, Nashville, Tennessee, United States of America
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Linh T. Trinh
- Center for Stem Cell Biology, Vanderbilt University, Nashville, Tennessee, United States of America
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Lily H. Kim
- College of Arts and Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Shristi Shrestha
- Center for Stem Cell Biology, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Jean-Philippe Cartailler
- Center for Stem Cell Biology, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Mark A. Magnuson
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States of America
- Center for Stem Cell Biology, Vanderbilt University, Nashville, Tennessee, United States of America
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, United States of America
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3
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Maksimov MO, Wu C, Ashbrook DG, Villani F, Colonna V, Mousavi N, Ma N, Lu L, Pritchard JK, Goren A, Williams RW, Palmer AA, Gymrek M. A novel quantitative trait locus implicates Msh3 in the propensity for genome-wide short tandem repeat expansions in mice. Genome Res 2023; 33:689-702. [PMID: 37127331 PMCID: PMC10317118 DOI: 10.1101/gr.277576.122] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 04/26/2023] [Indexed: 05/03/2023]
Abstract
Short tandem repeats (STRs) are a class of rapidly mutating genetic elements typically characterized by repeated units of 1-6 bp. We leveraged whole-genome sequencing data for 152 recombinant inbred (RI) strains from the BXD family of mice to map loci that modulate genome-wide patterns of new mutations arising during parent-to-offspring transmission at STRs. We defined quantitative phenotypes describing the numbers and types of germline STR mutations in each strain and performed quantitative trait locus (QTL) analyses for each of these phenotypes. We identified a locus on Chromosome 13 at which strains inheriting the C57BL/6J (B) haplotype have a higher rate of STR expansions than those inheriting the DBA/2J (D) haplotype. The strongest candidate gene in this locus is Msh3, a known modifier of STR stability in cancer and at pathogenic repeat expansions in mice and humans, as well as a current drug target against Huntington's disease. The D haplotype at this locus harbors a cluster of variants near the 5' end of Msh3, including multiple missense variants near the DNA mismatch recognition domain. In contrast, the B haplotype contains a unique retrotransposon insertion. The rate of expansion covaries positively with Msh3 expression-with higher expression from the B haplotype. Finally, detailed analysis of mutation patterns showed that strains carrying the B allele have higher expansion rates, but slightly lower overall total mutation rates, compared with those with the D allele, particularly at tetranucleotide repeats. Our results suggest an important role for inherited variants in Msh3 in modulating genome-wide patterns of germline mutations at STRs.
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Affiliation(s)
- Mikhail O Maksimov
- Department of Medicine, University of California San Diego, La Jolla, California 92093, USA
- Department of Computer Science and Engineering, University of California San Diego, La Jolla, California 92093, USA
| | - Cynthia Wu
- Bioinformatics and Systems Biology Program, University of California San Diego, La Jolla, California 92093, USA
| | - David G Ashbrook
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA
| | - Flavia Villani
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA
| | - Vincenza Colonna
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA
- Institute of Genetics and Biophysics, National Research Council, Naples 80111, Italy
| | - Nima Mousavi
- Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, California 92093, USA
| | - Nichole Ma
- Department of Medicine, University of California San Diego, La Jolla, California 92093, USA
| | - Lu Lu
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA
| | - Jonathan K Pritchard
- Department of Genetics, Stanford University, Stanford, California 94305, USA
- Department of Biology, Stanford University, Stanford, California 94305, USA
| | - Alon Goren
- Department of Medicine, University of California San Diego, La Jolla, California 92093, USA
- Institute for Genomic Medicine, University of California San Diego, La Jolla, California 92093, USA
| | - Robert W Williams
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA
| | - Abraham A Palmer
- Institute for Genomic Medicine, University of California San Diego, La Jolla, California 92093, USA
- Department of Psychiatry, Department of Medicine, University of California San Diego, La Jolla, California 92093, USA
| | - Melissa Gymrek
- Department of Medicine, University of California San Diego, La Jolla, California 92093, USA;
- Department of Computer Science and Engineering, University of California San Diego, La Jolla, California 92093, USA
- Institute for Genomic Medicine, University of California San Diego, La Jolla, California 92093, USA
- Department of Biomedical Informatics
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Bertozzi TM, Takahashi N, Hanin G, Kazachenka A, Ferguson-Smith AC. A spontaneous genetically induced epiallele at a retrotransposon shapes host genome function. eLife 2021; 10:e65233. [PMID: 33755012 PMCID: PMC8084528 DOI: 10.7554/elife.65233] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 03/22/2021] [Indexed: 12/14/2022] Open
Abstract
Intracisternal A-particles (IAPs) are endogenous retroviruses (ERVs) responsible for most insertional mutations in the mouse. Full-length IAPs harbour genes flanked by long terminal repeats (LTRs). Here, we identify a solo LTR IAP variant (Iap5-1solo) recently formed in the inbred C57BL/6J mouse strain. In contrast to the C57BL/6J full-length IAP at this locus (Iap5-1full), Iap5-1solo lacks DNA methylation and H3K9 trimethylation. The distinct DNA methylation levels between the two alleles are established during preimplantation development, likely due to loss of KRAB zinc finger protein binding at the Iap5-1solo variant. Iap5-1solo methylation increases and becomes more variable in a hybrid genetic background yet is unresponsive to maternal dietary methyl supplementation. Differential epigenetic modification of the two variants is associated with metabolic differences and tissue-specific changes in adjacent gene expression. Our characterisation of Iap5-1 as a genetically induced epiallele with functional consequences establishes a new model to study transposable element repression and host-element co-evolution.
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Affiliation(s)
- Tessa M Bertozzi
- Department of Genetics, University of CambridgeCambridgeUnited Kingdom
| | - Nozomi Takahashi
- Department of Genetics, University of CambridgeCambridgeUnited Kingdom
| | - Geula Hanin
- Department of Genetics, University of CambridgeCambridgeUnited Kingdom
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Nohara K, Nakabayashi K, Okamura K, Suzuki T, Suzuki S, Hata K. Gestational arsenic exposure induces site-specific DNA hypomethylation in active retrotransposon subfamilies in offspring sperm in mice. Epigenetics Chromatin 2020; 13:53. [PMID: 33267854 PMCID: PMC7709384 DOI: 10.1186/s13072-020-00375-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Accepted: 11/12/2020] [Indexed: 01/26/2023] Open
Abstract
Background Environmental impacts on a fetus can disrupt germ cell development leading to epimutations in mature germ cells. Paternal inheritance of adverse health effects through sperm epigenomes, including DNA methylomes, has been recognized in human and animal studies. However, the impacts of gestational exposure to a variety of environmental factors on the germ cell epigenomes are not fully investigated. Arsenic, a naturally occurring contaminant, is one of the most concerning environmental chemicals, that is causing serious health problems, including an increase in cancer, in highly contaminated areas worldwide. We previously showed that gestational arsenic exposure of pregnant C3H mice paternally induces hepatic tumor increase in the second generation (F2). In the present study, we have investigated the F1 sperm DNA methylomes genome-widely by one-base resolution analysis using a reduced representation bisulfite sequencing (RRBS) method. Results We have clarified that gestational arsenic exposure increases hypomethylated cytosines in all the chromosomes and they are significantly overrepresented in the retrotransposon LINEs and LTRs, predominantly in the intergenic regions. Closer analyses of detailed annotated DNA sequences showed that hypomethylated cytosines are especially accumulated in the promoter regions of the active full-length L1MdA subfamily in LINEs, and 5′LTRs of the active IAPE subfamily in LTRs. This is the first report that has identified the specific positions of methylomes altered in the retrotransposon elements by environmental exposure, by genome-wide methylome analysis. Conclusion Lowered DNA methylation potentially enhances L1MdA retrotransposition and cryptic promoter activity of 5′LTR for coding genes and non-coding RNAs. The present study has illuminated the environmental impacts on sperm DNA methylome establishment that can lead to augmented retrotransposon activities in germ cells and can cause harmful effects in the following generation.
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Affiliation(s)
- Keiko Nohara
- Center for Health and Environmental Risk Research, National Institute for Environmental Studies, Tsukuba, 305-8506, Japan.
| | - Kazuhiko Nakabayashi
- Department of Maternal-Fetal Biology, National Center for Child Health and Development, Tokyo, 157-8535, Japan
| | - Kazuyuki Okamura
- Center for Health and Environmental Risk Research, National Institute for Environmental Studies, Tsukuba, 305-8506, Japan
| | - Takehiro Suzuki
- Center for Health and Environmental Risk Research, National Institute for Environmental Studies, Tsukuba, 305-8506, Japan
| | - Shigekatsu Suzuki
- Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, Tsukuba, 305-8506, Japan
| | - Kenichiro Hata
- Department of Maternal-Fetal Biology, National Center for Child Health and Development, Tokyo, 157-8535, Japan
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Rebollo R, Galvão-Ferrarini M, Gagnier L, Zhang Y, Ferraj A, Beck CR, Lorincz MC, Mager DL. Inter-Strain Epigenomic Profiling Reveals a Candidate IAP Master Copy in C3H Mice. Viruses 2020; 12:v12070783. [PMID: 32708087 PMCID: PMC7411935 DOI: 10.3390/v12070783] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 07/03/2020] [Accepted: 07/13/2020] [Indexed: 12/15/2022] Open
Abstract
Insertions of endogenous retroviruses cause a significant fraction of mutations in inbred mice but not all strains are equally susceptible. Notably, most new Intracisternal A particle (IAP) ERV mutagenic insertions have occurred in C3H mice. We show here that strain-specific insertional polymorphic IAPs accumulate faster in C3H/HeJ mice, relative to other sequenced strains, and that IAP transcript levels are higher in C3H/HeJ embryonic stem (ES) cells compared to other ES cells. To investigate the mechanism for high IAP activity in C3H mice, we identified 61 IAP copies in C3H/HeJ ES cells enriched with H3K4me3 (a mark of active promoters) and, among those tested, all are unmethylated in C3H/HeJ ES cells. Notably, 13 of the 61 are specific to C3H/HeJ and are members of the non-autonomous 1Δ1 IAP subfamily that is responsible for nearly all new insertions in C3H. One copy is full length with intact open reading frames and hence potentially capable of providing proteins in trans to other 1Δ1 elements. This potential “master copy” is present in other strains, including 129, but its 5’ long terminal repeat (LTR) is methylated in 129 ES cells. Thus, the unusual IAP activity in C3H may be due to reduced epigenetic repression coupled with the presence of a master copy.
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Affiliation(s)
- Rita Rebollo
- Terry Fox Laboratory, British Columbia Cancer, Vancouver, BC V5Z1L3, Canada; (L.G.); (Y.Z.)
- University of Lyon, INSA-Lyon, INRA, BF2i, UMR0203, F-69621 Villeurbanne, France;
- Correspondence: (R.R.); (D.L.M.)
| | | | - Liane Gagnier
- Terry Fox Laboratory, British Columbia Cancer, Vancouver, BC V5Z1L3, Canada; (L.G.); (Y.Z.)
| | - Ying Zhang
- Terry Fox Laboratory, British Columbia Cancer, Vancouver, BC V5Z1L3, Canada; (L.G.); (Y.Z.)
| | - Ardian Ferraj
- Department of Genetics and Genome Sciences, University of Connecticut Health Center, Farmington, CT 06030, USA; (A.F.); (C.R.B.)
| | - Christine R. Beck
- Department of Genetics and Genome Sciences, University of Connecticut Health Center, Farmington, CT 06030, USA; (A.F.); (C.R.B.)
- The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032, USA
| | - Matthew C. Lorincz
- Department of Medical Genetics, University of British Columbia, Vancouver, BC V6T1Z3, Canada;
| | - Dixie L. Mager
- Terry Fox Laboratory, British Columbia Cancer, Vancouver, BC V5Z1L3, Canada; (L.G.); (Y.Z.)
- Department of Medical Genetics, University of British Columbia, Vancouver, BC V6T1Z3, Canada;
- Correspondence: (R.R.); (D.L.M.)
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DNA methylation dynamics at transposable elements in mammals. Essays Biochem 2020; 63:677-689. [PMID: 31654072 DOI: 10.1042/ebc20190039] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Revised: 09/29/2019] [Accepted: 09/30/2019] [Indexed: 12/18/2022]
Abstract
Transposable elements dominate the mammalian genome, but their contribution to genetic and epigenetic regulation has been largely overlooked. This was in part due to technical limitations, which made the study of repetitive sequences at single copy resolution difficult. The advancement of next-generation sequencing assays in the last decade has greatly enhanced our understanding of transposable element function. In some instances, specific transposable elements are thought to have been co-opted into regulatory roles during both mouse and human development, while in disease such regulatory potential can contribute to malignancy. DNA methylation is arguably the best characterised regulator of transposable element activity. DNA methylation is associated with transposable element repression, and acts to limit their genotoxic potential. In specific developmental contexts, erasure of DNA methylation is associated with a burst of transposable element expression. Developmental regulation of DNA methylation enables transposon activation, ensuring their survival and propagation throughout the host genome, and also allows the host access to regulatory sequences encoded within the elements. Here I discuss DNA methylation at transposable elements, describing its function and dynamic regulation throughout murine and human development.
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Kremsky I, Corces VG. Protection from DNA re-methylation by transcription factors in primordial germ cells and pre-implantation embryos can explain trans-generational epigenetic inheritance. Genome Biol 2020; 21:118. [PMID: 32423419 PMCID: PMC7236515 DOI: 10.1186/s13059-020-02036-w] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 05/05/2020] [Indexed: 12/16/2022] Open
Abstract
Background A growing body of evidence suggests that certain epiphenotypes can be passed across generations via both the male and female germlines of mammals. These observations have been difficult to explain owing to a global loss of the majority of known epigenetic marks present in parental chromosomes during primordial germ cell development and after fertilization. Results By integrating previously published BS-seq, DNase-seq, ATAC-seq, and RNA-seq data collected during multiple stages of primordial germ cell and pre-implantation development, we find that the methylation status of the majority of CpGs genome-wide is restored after global de-methylation, despite the fact that global CpG methylation drops to 10% in primordial germ cells and 20% in the inner cell mass of the blastocyst. We estimate the proportion of such CpGs with preserved methylation status to be 78%. Further, we find that CpGs at sites bound by transcription factors during the global re-methylation phases of germline and embryonic development remain hypomethylated across all developmental stages observed. On the other hand, CpGs at sites not bound by transcription factors during the global re-methylation phase have high methylation levels prior to global de-methylation, become de-methylated during global de-methylation, and then become re-methylated. Conclusions The results suggest that transcription factors can act as carriers of epigenetic information during germ cell and pre-implantation development by ensuring that the methylation status of CpGs is maintained. These findings provide the basis for a mechanistic description of trans-generational inheritance of epigenetic information in mammals.
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Affiliation(s)
- Isaac Kremsky
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Victor G Corces
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, 30322, USA.
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Perera BP, Faulk C, Svoboda LK, Goodrich JM, Dolinoy DC. The role of environmental exposures and the epigenome in health and disease. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:176-192. [PMID: 31177562 PMCID: PMC7252203 DOI: 10.1002/em.22311] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 05/29/2019] [Accepted: 06/03/2019] [Indexed: 05/02/2023]
Abstract
The genetic material of every organism exists within the context of regulatory networks that govern gene expression, collectively called the epigenome. Epigenetics has taken center stage in the study of diseases such as cancer and diabetes, but its integration into the field of environmental health is still emerging. As the Environmental Mutagenesis and Genomics Society (EMGS) celebrates its 50th Anniversary this year, we have come together to review and summarize the seminal advances in the field of environmental epigenomics. Specifically, we focus on the role epigenetics may play in multigenerational and transgenerational transmission of environmentally induced health effects. We also summarize state of the art techniques for evaluating the epigenome, environmental epigenetic analysis, and the emerging field of epigenome editing. Finally, we evaluate transposon epigenetics as they relate to environmental exposures and explore the role of noncoding RNA as biomarkers of environmental exposures. Although the field has advanced over the past several decades, including being recognized by EMGS with its own Special Interest Group, recently renamed Epigenomics, we are excited about the opportunities for environmental epigenetic science in the next 50 years. Environ. Mol. Mutagen. 61:176-192, 2020. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- Bambarendage P.U. Perera
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, Michigan
| | - Christopher Faulk
- Department of Animal Sciences, University of Minnesota, St. Paul, Minnesota
| | - Laurie K. Svoboda
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, Michigan
| | - Jaclyn M. Goodrich
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, Michigan
| | - Dana C. Dolinoy
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, Michigan
- Department of Nutritional Sciences, University of Michigan School of Public Health, Ann Arbor, Michigan
- Correspondence to: Dana C. Dolinoy, Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, Michigan.
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Hron T, Fabryova H, Elleder D. Insight into the epigenetic landscape of a currently endogenizing gammaretrovirus in mule deer (Odocoileus hemionus). Genomics 2019; 112:886-896. [PMID: 31175981 DOI: 10.1016/j.ygeno.2019.06.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 04/26/2019] [Accepted: 06/03/2019] [Indexed: 01/22/2023]
Abstract
Endogenous retroviruses (ERVs) constitute a significant part of vertebrate genomes. They originated from past retroviral infections and some of them retain transcriptional activity. The key mechanism avoiding uncontrolled ERV transcription is DNA methylation-mediated epigenetic silencing. Despite numerous studies describing the involvement of ERV activity in cellular processes, epigenetic regulation of ERVs is still poorly understood. We previously described a cervid endogenous retrovirus (CrERV) in the mule deer genome. This virus exhibits massive insertional polymorphism, suggesting recent activity. Here we employed NGS-based strategy to determine the methylation pattern of CrERV integrations in four mule deer. Besides the vast majority of methylated integrations, we identified a tiny fraction of demethylated proviral copies. These copies represent evolutionary older integrations located near gene promoters. In general, our work is a first attempt to characterize the epigenetic landscape of insertionally polymorphic ERV on a whole-genome scale and offers insight into its interactions with a host.
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Affiliation(s)
- Tomas Hron
- Institute of Molecular Genetics, The Czech Academy of Sciences, Videnska 1083, Prague, 14220, Czech Republic; Faculty of Science, Charles University, Albertov 6, 128 43 Praha 2, Czech Republic.
| | - Helena Fabryova
- Institute of Molecular Genetics, The Czech Academy of Sciences, Videnska 1083, Prague, 14220, Czech Republic; Faculty of Science, Charles University, Albertov 6, 128 43 Praha 2, Czech Republic
| | - Daniel Elleder
- Institute of Molecular Genetics, The Czech Academy of Sciences, Videnska 1083, Prague, 14220, Czech Republic.
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11
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Pathak R, Feil R. Environmental effects on chromatin repression at imprinted genes and endogenous retroviruses. Curr Opin Chem Biol 2018; 45:139-147. [DOI: 10.1016/j.cbpa.2018.04.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 04/05/2018] [Accepted: 04/24/2018] [Indexed: 12/26/2022]
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