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Impaired transcription of human endogenous retroviruses in the sperm with exception of syncytin 1: short communication. Mol Biol Rep 2021; 48:5803-5808. [PMID: 34302264 DOI: 10.1007/s11033-021-06577-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 07/16/2021] [Indexed: 12/22/2022]
Abstract
BACKGROUND Human endogenous retroviruses (HERVs), remnants of ancestral infections, represent 8% of the human genome. HERVs are co-opted for important physiological functions during embryogenesis; however, little is known about their expression in human gametes. We evaluated the transcriptional levels of several retroviral sequences in human spermatozoa. METHODS AND RESULTS We assessed, through a Real-Time PCR assay, the transcription levels of the pol genes of HERV-H, -K and -W families and of env genes of syncytin (Syn)1 and Syn2 in the spermatozoa from 8 normospermic subjects. The entity and distribution of their expressions were compared to values found in white blood cells (WBCs) from 16 healthy volunteers. The level of HERV transcripts was significantly lower in spermatozoa than in WBCs for HERV-H-pol, HERV-K-pol, HERV-W-pol, and Syn2.In contrast, the level of expression of Syn1 in the sperm was similar to that found in WBCs and it was significantly higher than the mRNA concentrations of other HERV genes in spermatozoa. CONCLUSIONS Our findings show, for the first time, the presence of several retroviral mRNAs in the sperm, although in low amounts. The higher concentration of Syn1 suggests that it could play a key role in the fusion process between gametes during fertilization and, perhaps, be involved in embryo development. Further studies could clarify whether aberrant HERV expressions, in particular of Syn1, negatively affect fertilization and embryo growth and whether sperm manipulation procedures, such as cryopreservation, may potentially influence HERV transcription in the human male gamete.
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Yedavalli VRK, Patil A, Parrish J, Kozak CA. A novel class III endogenous retrovirus with a class I envelope gene in African frogs with an intact genome and developmentally regulated transcripts in Xenopus tropicalis. Retrovirology 2021; 18:20. [PMID: 34261506 PMCID: PMC8278194 DOI: 10.1186/s12977-021-00564-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 06/29/2021] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Retroviruses exist as exogenous infectious agents and as endogenous retroviruses (ERVs) integrated into host chromosomes. Such endogenous retroviruses (ERVs) are grouped into three classes roughly corresponding to the seven genera of infectious retroviruses: class I (gamma-, epsilonretroviruses), class II (alpha-, beta-, delta-, lentiretroviruses) and class III (spumaretroviruses). Some ERVs have counterparts among the known infectious retroviruses, while others represent paleovirological relics of extinct or undiscovered retroviruses. RESULTS Here we identify an intact ERV in the Anuran amphibian, Xenopus tropicalis. XtERV-S has open reading frames (ORFs) for gag, pol (polymerase) and env (envelope) genes, with a small additional ORF in pol and a serine tRNA primer binding site. It has unusual features and domain relationships to known retroviruses. Analyses based on phylogeny and functional motifs establish that XtERV-S gag and pol genes are related to the ancient env-less class III ERV-L family but the surface subunit of env is unrelated to known retroviruses while its transmembrane subunit is class I-like. LTR constructs show transcriptional activity, and XtERV-S transcripts are detected in embryos after the maternal to zygotic mid-blastula transition and before the late tailbud stage. Tagged Gag protein shows typical subcellular localization. The presence of ORFs in all three protein-coding regions along with identical 5' and 3' LTRs (long terminal repeats) indicate this is a very recent germline acquisition. There are older, full-length, nonorthologous, defective copies in Xenopus laevis and the distantly related African bullfrog, Pyxicephalus adspersus. Additional older, internally deleted copies in X. tropicalis carry a 300 bp LTR substitution. CONCLUSIONS XtERV-S represents a genera-spanning member of the largely env-less class III ERV that has ancient and modern copies in Anurans. This provirus has an env ORF with a surface subunit unrelated to known retroviruses and a transmembrane subunit related to class I gammaretroviruses in sequence and organization, and is expressed in early embryogenesis. Additional XtERV-S-related but defective copies are present in X. tropicalis and other African frog taxa. XtERV-S is an unusual class III ERV variant, and it may represent an important transitional retroviral form that has been spreading in African frogs for tens of millions of years.
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Affiliation(s)
- Venkat R K Yedavalli
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, Bethesda, MD, 20892, USA
| | - Akash Patil
- Department of Biomedical Engineering, John Hopkins University, Baltimore, MD, 21205, USA
| | - Janay Parrish
- Internal Medicine, Northwell Health, Lenox Hill Hospital, New York, NY, 10075, USA
| | - Christine A Kozak
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, Bethesda, MD, 20892, USA.
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Le Tortorec A, Matusali G, Mahé D, Aubry F, Mazaud-Guittot S, Houzet L, Dejucq-Rainsford N. From Ancient to Emerging Infections: The Odyssey of Viruses in the Male Genital Tract. Physiol Rev 2020; 100:1349-1414. [PMID: 32031468 DOI: 10.1152/physrev.00021.2019] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The male genital tract (MGT) is the target of a number of viral infections that can have deleterious consequences at the individual, offspring, and population levels. These consequences include infertility, cancers of male organs, transmission to the embryo/fetal development abnormalities, and sexual dissemination of major viral pathogens such as human immunodeficiency virus (HIV) and hepatitis B virus. Lately, two emerging viruses, Zika and Ebola, have additionally revealed that the human MGT can constitute a reservoir for viruses cleared from peripheral circulation by the immune system, leading to their sexual transmission by cured men. This represents a concern for future epidemics and further underlines the need for a better understanding of the interplay between viruses and the MGT. We review here how viruses, from ancient viruses that integrated the germline during evolution through old viruses (e.g., papillomaviruses originating from Neanderthals) and more modern sexually transmitted infections (e.g., simian zoonotic HIV) to emerging viruses (e.g., Ebola and Zika) take advantage of genital tract colonization for horizontal dissemination, viral persistence, vertical transmission, and endogenization. The MGT immune responses to viruses and the impact of these infections are discussed. We summarize the latest data regarding the sources of viruses in semen and the complex role of this body fluid in sexual transmission. Finally, we introduce key animal findings that are relevant for our understanding of viral infection and persistence in the human MGT and suggest future research directions.
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Affiliation(s)
- Anna Le Tortorec
- University of Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail)-UMR_S1085, Rennes, France
| | - Giulia Matusali
- University of Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail)-UMR_S1085, Rennes, France
| | - Dominique Mahé
- University of Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail)-UMR_S1085, Rennes, France
| | - Florence Aubry
- University of Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail)-UMR_S1085, Rennes, France
| | - Séverine Mazaud-Guittot
- University of Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail)-UMR_S1085, Rennes, France
| | - Laurent Houzet
- University of Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail)-UMR_S1085, Rennes, France
| | - Nathalie Dejucq-Rainsford
- University of Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail)-UMR_S1085, Rennes, France
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Marino D, Perković M, Hain A, Jaguva Vasudevan AA, Hofmann H, Hanschmann KM, Mühlebach MD, Schumann GG, König R, Cichutek K, Häussinger D, Münk C. APOBEC4 Enhances the Replication of HIV-1. PLoS One 2016; 11:e0155422. [PMID: 27249646 PMCID: PMC4889046 DOI: 10.1371/journal.pone.0155422] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 04/28/2016] [Indexed: 12/24/2022] Open
Abstract
APOBEC4 (A4) is a member of the AID/APOBEC family of cytidine deaminases. In this study we found a high mRNA expression of A4 in human testis. In contrast, there were only low levels of A4 mRNA detectable in 293T, HeLa, Jurkat or A3.01 cells. Ectopic expression of A4 in HeLa cells resulted in mostly cytoplasmic localization of the protein. To test whether A4 has antiviral activity similar to that of proteins of the APOBEC3 (A3) subfamily, A4 was co-expressed in 293T cells with wild type HIV-1 and HIV-1 luciferase reporter viruses. We found that A4 did not inhibit the replication of HIV-1 but instead enhanced the production of HIV-1 in a dose-dependent manner and seemed to act on the viral LTR. A4 did not show detectable cytidine deamination activity in vitro and weakly interacted with single-stranded DNA. The presence of A4 in virus producer cells enhanced HIV-1 replication by transiently transfected A4 or stably expressed A4 in HIV-susceptible cells. APOBEC4 was capable of similarly enhancing transcription from a broad spectrum of promoters, regardless of whether they were viral or mammalian. We hypothesize that A4 may have a natural role in modulating host promoters or endogenous LTR promoters.
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Affiliation(s)
- Daniela Marino
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
- Division of Medical Biotechnology, Paul-Ehrlich-Institute, Langen, Germany
| | - Mario Perković
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
- Division of Medical Biotechnology, Paul-Ehrlich-Institute, Langen, Germany
| | - Anika Hain
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Ananda A. Jaguva Vasudevan
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Henning Hofmann
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
- Division of Medical Biotechnology, Paul-Ehrlich-Institute, Langen, Germany
| | | | - Michael D. Mühlebach
- Division of Medical Biotechnology, Paul-Ehrlich-Institute, Langen, Germany
- Product Testing of Immunological Medicinal Products for Veterinary Uses, Paul-Ehrlich-Institute, Langen, Germany
| | - Gerald G. Schumann
- Division of Medical Biotechnology, Paul-Ehrlich-Institute, Langen, Germany
| | - Renate König
- Host-Pathogen Interactions, Paul-Ehrlich-Institute, Langen, Germany
- Sanford Burnham Prebys Medical Discovery Institute, Immunity and Pathogenesis Program, La Jolla, California, United States of America
| | - Klaus Cichutek
- Division of Medical Biotechnology, Paul-Ehrlich-Institute, Langen, Germany
| | - Dieter Häussinger
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Carsten Münk
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
- Division of Medical Biotechnology, Paul-Ehrlich-Institute, Langen, Germany
- * E-mail:
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Díaz-Carballo D, Acikelli AH, Klein J, Jastrow H, Dammann P, Wyganowski T, Guemues C, Gustmann S, Bardenheuer W, Malak S, Tefett NS, Khosrawipour V, Giger-Pabst U, Tannapfel A, Strumberg D. Therapeutic potential of antiviral drugs targeting chemorefractory colorectal adenocarcinoma cells overexpressing endogenous retroviral elements. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2015; 34:81. [PMID: 26260344 PMCID: PMC4542094 DOI: 10.1186/s13046-015-0199-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 07/30/2015] [Indexed: 12/31/2022]
Abstract
Background Endoretroviruses account for circa 8 % of all transposable elements found in the genome of humans and other animals. They represent a genetic footprint of ancestral germ-cell infections of exoviruses that is transmittable to the progeny by Mendelian segregation. Traces of human endogenous retroviruses are physiologically expressed in ovarial, testicular and placental tissues as well as in stem cells. In addition, a number of these fossil viral elements have also been related to carcinogenesis. However, a relation between endoretroviruses expression and chemoresistance has not been reported yet. Methods Twenty colorectal carcinoma patient samples were scrutinized for HERV-WE1 and HERV-FRD1 endoretroviruses using immunohistochemical approaches. In order to search for differential expression of these elements in chemotherapy refractory cells, a resistant HCT8 colon carcinoma subline was developed by serial etoposide exposure. Endoretroviral elements were detected by immunocytochemical staining, qPCR and ELISA. IC50-values of antiviral and cytostatic drugs in HCT8 cells were determined by MTT proliferation assay. The antivirals-cytostatics interaction was evaluated by the isobologram method. Results In this work, we show for the first time that HERV-WE1, HERV-FRD1, HERV-31, and HERV-V1 are a) simultaneously expressed in treatment-naïve colon carcinoma cells and b) upregulated after cytostatic exposure, suggesting that these retroviral elements are intimately related to chemotherapy resistance. We found a number of antiviral drugs to have cytotoxic activity and the ability to force the downregulation of HERV proteins in vitro. We also demonstrate that the use of different antiviral compounds alone or in combination with anticancer agents results in a synergistic antiproliferative effect and downregulation of different endoretroviral elements in highly chemotherapy-resistant colorectal tumor cells. Conclusions Enhanced HERV-expression is associated with chemoresistance in colon carcinomas which can be overcome by antiviral drugs alone or in combination with anticancer drugs. Therefore, the introduction of antiviral compounds to the current chemotherapy regimens potentially improves patient outcomes. Electronic supplementary material The online version of this article (doi:10.1186/s13046-015-0199-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- David Díaz-Carballo
- Institute for Molecular Oncology and Experimental Therapeutics, Division of Oncology and Hematology, Marienhospital Herne, Ruhr University of Bochum, Medical School, Marienhospital Herne, Duengelstr. 33, 44623, Herne, Germany.
| | - Ali Haydar Acikelli
- Institute for Molecular Oncology and Experimental Therapeutics, Division of Oncology and Hematology, Marienhospital Herne, Ruhr University of Bochum, Medical School, Marienhospital Herne, Duengelstr. 33, 44623, Herne, Germany
| | - Jacqueline Klein
- Institute for Molecular Oncology and Experimental Therapeutics, Division of Oncology and Hematology, Marienhospital Herne, Ruhr University of Bochum, Medical School, Marienhospital Herne, Duengelstr. 33, 44623, Herne, Germany
| | - Holger Jastrow
- Institute of Anatomy and Experimental Morphology, University of Duisburg-Essen, Medical School, Essen, Germany
| | - Philipp Dammann
- Central Animal Laboratory, University of Duisburg-Essen, Medical School, Essen, Germany
| | - Thomas Wyganowski
- Institute for Molecular Oncology and Experimental Therapeutics, Division of Oncology and Hematology, Marienhospital Herne, Ruhr University of Bochum, Medical School, Marienhospital Herne, Duengelstr. 33, 44623, Herne, Germany
| | - Cihan Guemues
- Institute for Molecular Oncology and Experimental Therapeutics, Division of Oncology and Hematology, Marienhospital Herne, Ruhr University of Bochum, Medical School, Marienhospital Herne, Duengelstr. 33, 44623, Herne, Germany
| | - Sebastian Gustmann
- Institute for Molecular Oncology and Experimental Therapeutics, Division of Oncology and Hematology, Marienhospital Herne, Ruhr University of Bochum, Medical School, Marienhospital Herne, Duengelstr. 33, 44623, Herne, Germany
| | - Walter Bardenheuer
- Institute for Molecular Oncology and Experimental Therapeutics, Division of Oncology and Hematology, Marienhospital Herne, Ruhr University of Bochum, Medical School, Marienhospital Herne, Duengelstr. 33, 44623, Herne, Germany
| | - Sascha Malak
- Institute for Molecular Oncology and Experimental Therapeutics, Division of Oncology and Hematology, Marienhospital Herne, Ruhr University of Bochum, Medical School, Marienhospital Herne, Duengelstr. 33, 44623, Herne, Germany
| | - Nora Sophia Tefett
- Institute for Molecular Oncology and Experimental Therapeutics, Division of Oncology and Hematology, Marienhospital Herne, Ruhr University of Bochum, Medical School, Marienhospital Herne, Duengelstr. 33, 44623, Herne, Germany
| | - Veria Khosrawipour
- Department of Visceral Surgery, Marienhospital Herne, Ruhr University of Bochum, Medical School, Herne, Germany
| | - Urs Giger-Pabst
- Department of Visceral Surgery, Marienhospital Herne, Ruhr University of Bochum, Medical School, Herne, Germany
| | - Andrea Tannapfel
- Institute of Pathology, Ruhr-University of Bochum, Medical School, Bochum, Germany
| | - Dirk Strumberg
- Institute for Molecular Oncology and Experimental Therapeutics, Division of Oncology and Hematology, Marienhospital Herne, Ruhr University of Bochum, Medical School, Marienhospital Herne, Duengelstr. 33, 44623, Herne, Germany
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Antony JM, Deslauriers AM, Bhat RK, Ellestad KK, Power C. Human endogenous retroviruses and multiple sclerosis: innocent bystanders or disease determinants? Biochim Biophys Acta Mol Basis Dis 2010; 1812:162-76. [PMID: 20696240 PMCID: PMC7172332 DOI: 10.1016/j.bbadis.2010.07.016] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2009] [Revised: 07/14/2010] [Accepted: 07/26/2010] [Indexed: 12/21/2022]
Abstract
Human endogenous retroviruses (HERVs) constitute 5–8% of human genomic DNA and are replication incompetent despite expression of individual HERV genes from different chromosomal loci depending on the specific tissue. Several HERV genes have been detected as transcripts and proteins in the central nervous system, frequently in the context of neuroinflammation. The HERV-W family has received substantial attention in large part because of associations with diverse syndromes including multiple sclerosis (MS) and several psychiatric disorders. A HERV-W-related retroelement, multiple sclerosis retrovirus (MSRV), has been reported in MS patients to be both a biomarker as well as an effector of aberrant immune responses. HERV-H and HERV-K have also been implicated in MS and other neurological diseases but await delineation of their contributions to disease. The HERV-W envelope-encoded glycosylated protein, syncytin-1, is encoded by chromosome 7q21 and exhibits increased glial expression within MS lesions. Overexpression of syncytin-1 in glia induces endoplasmic reticulum stress leading to neuroinflammation and the induction of free radicals, which damage proximate cells. Syncytin-1's receptor, ASCT1 is a neutral amino acid transporter expressed on glia and is suppressed in white matter of MS patients. Of interest, antioxidants ameliorate syncytin-1's neuropathogenic effects raising the possibility of using these agents as therapeutics for neuroinflammatory diseases. Given the multiple insertion sites of HERV genes as complete and incomplete open reading frames, together with their differing capacity to be expressed and the complexities of individual HERVs as both disease markers and bioactive effectors, HERV biology is a compelling area for understanding neuropathogenic mechanisms and developing new therapeutic strategies.
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Abstract
Retrotransposons, mainly LINEs, SINEs, and endogenous retroviruses, make up roughly 40% of the mammalian genome and have played an important role in genome evolution. Their prevalence in genomes reflects a delicate balance between their further expansion and the restraint imposed by the host. In any human genome only a small number of LINE1s (L1s) are active, moving their own and SINE sequences into new genomic locations and occasionally causing disease. Recent insights and new technologies promise answers to fundamental questions about the biology of transposable elements.
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Affiliation(s)
- John L Goodier
- Department of Genetics, University of Pennsylvania School of Medicine, 415 Curie Boulevard, Philadelphia, PA 19104, USA.
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Spadafora C. A reverse transcriptase-dependent mechanism plays central roles in fundamental biological processes. Syst Biol Reprod Med 2008; 54:11-21. [PMID: 18543862 DOI: 10.1080/19396360701876815] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
This review summarizes emerging evidence that LINE-1 (Long Interspersed Nuclear Elements) -encoded reverse transcriptase (RT) regulates fundamental biological processes. Earlier studies showed that sperm cells can be used as vectors of both exogenous DNA and RNA molecules in sperm-mediated gene transfer assays. During these studies, a sperm endogenous RT activity was identified, which can reverse-transcribe exogenous RNA directly, or DNA molecules through sequential transcription and reverse transcription. Resulting cDNA copies generated in sperm cells can be delivered to embryos at fertilization, further propagated in tissues as low-copy extrachromosomal structures and transmitted to the progeny in a non-mendelian fashion. Being transcriptionally competent, they can induce phenotypic variations in positive tissues. An RT activity is also present in preimplantation embryos, and its inhibition causes developmental arrest in early preimplantation stages, paralleled by an extensive reprogramming of gene expression. In analogy with this, drug-mediated inhibition of RT activity, or RNA interference-mediated silencing of human LINE-1, reduce cell proliferation and induce differentiation in a variety of cancer cell lines. Furthermore, RT inhibition in vivo antagonizes the growth of human tumors in animal models. As a whole, these data implicate a RT-dependent machinery in the genesis of new genetic information in spermatozoa and in normal and pathological developmental processes.
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An integrase of endogenous retrovirus is involved in maternal mitochondrial DNA inheritance of the mouse. Biochem Biophys Res Commun 2008; 366:206-11. [DOI: 10.1016/j.bbrc.2007.11.127] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2007] [Accepted: 11/20/2007] [Indexed: 11/22/2022]
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