scholarly journals Relative Age of Proviral Porcine Endogenous Retrovirus Sequences in Sus scrofa Based on the Molecular Clock Hypothesis

2003 ◽  
Vol 77 (22) ◽  
pp. 12363-12368 ◽  
Author(s):  
Ralf R. Tönjes ◽  
Marcus Niebert
Keyword(s):  
Sus Scrofa ◽  
Endogenous Retrovirus ◽  
Endogenous Retroviruses ◽  
Relative Age ◽  
Repeat Structure ◽  
Porcine Endogenous Retrovirus ◽  
Porcine Endogenous Retroviruses ◽  
Different Types ◽  
Pecari Tajacu ◽  
Recent Origin

ABSTRACT Porcine endogenous retroviruses (PERV) are discussed as putative infectious agents in xenotransplantation. PERV classes A, B, and C harbor different envelope proteins. Two different types of long terminal repeat (LTR) structures exist, of which both are present only in PERV-A. One type of LTR contains a distinct repeat structure in U3, while the other is repeatless, conferring a lower level of transcriptional activity. Since the different LTR structures are distributed unequally among the proviruses and, apparently, PERV is the only virus harboring two different LTR structures, we were interested in determining which LTR is the ancestor. Replication-competent viruses can still be found today, suggesting an evolutionary recent origin. Our studies revealed that the age of PERV is at most 7.6 × 106 years, whereas the repeatless LTR type evolved approximately 3.4 × 106 years ago, being the phylogenetically younger structure. The age determined for PERV correlates with the time of separation between pigs (Suidae, Sus scrofa) and their closest relatives, American-born peccaries (Tayassuidae, Pecari tajacu), 7.4 × 106 years ago.

scholarly journals Isolation and Characterization of an Infectious Replication-Competent Molecular Clone of Ecotropic Porcine Endogenous Retrovirus Class C

2006 ◽  
Vol 80 (20) ◽  
pp. 10258-10261 ◽  
Author(s):  
Thomas Preuss ◽  
Nicole Fischer ◽  
Klaus Boller ◽  
Ralf R. Tönjes
Keyword(s):  
T Cells ◽  
Genomic Library ◽  
Endogenous Retrovirus ◽  
Endogenous Retroviruses ◽  
Miniature Swine ◽  
Infectious Risk ◽  
Isolation And Characterization ◽  
Porcine Endogenous Retrovirus ◽  
Porcine Endogenous Retroviruses

ABSTRACT Xenotransplantation of pig organs is complicated by the existence of polytropic replication-competent porcine endogenous retroviruses (PERV) capable of infecting human cells. The potential for recombination between ecotropic PERV-C and human-tropic PERV-A and PERV-B adds another level of infectious risk. Proviral PERV-C were characterized in MAX-T cells derived from d/d haplotype miniature swine. Three proviruses were cloned from a genomic library. Clone PERV-C(1312) generated infectious particles after transfection into porcine ST-IOWA cells. Electron microscopy revealed the same morphologies of virions in MAX-T cells and in ST-IOWA cells infected with cell-free PERV-C(1312) particles, indicating that MAX-T cells harbor one functional PERV-C provirus.

scholarly journals Genotyping of Porcine Endogenous Retroviruses from a Family of Miniature Swine

2004 ◽  
Vol 78 (1) ◽  
pp. 314-319 ◽  
Author(s):  
Gary Quinn ◽  
James Wood ◽  
Kristen Suling ◽  
Scott Arn ◽  
David H. Sachs ◽  
...  
Keyword(s):  
Endogenous Retrovirus ◽  
Endogenous Retroviruses ◽  
Target Cells ◽  
Nucleotide Polymorphisms ◽  
Miniature Swine ◽  
Porcine Endogenous Retrovirus ◽  
Porcine Endogenous Retroviruses ◽  
The Family ◽  
Transcript Profiles

ABSTRACT The identification of animals in an inbred miniature swine herd that consistently fail to produce replication- competent humantropic porcine endogenous retrovirus (PERV) has prompted studies on the biology of PERV in transmitter and nontransmitter animals. We analyzed PERV RNA transcript profiles in a family of inbred miniature swine (SLAd/d haplotype) in which individual members differed in their capacity to generate humantropic and ecotropic (i.e., pigtropic) virus. We identified unique HaeIII and HpaII gag restriction fragment length polymorphism (RFLP) profiles resulting from single nucleotide polymorphisms in blood cells; these were found only in animals that produced humantropic PERV. These HaeIII and HpaII gag RFLP profiles proved to be components of humantropic PERV as they were transmitted to 293 human target cells in vitro. The humantropic HaeIII and HpaII gag RFLP genotypes in the family of study were not present in other miniature swine in the herd that produced humantropic PERV, indicating that these RFLP profiles relate specifically to this family's lineage.

scholarly journals Characterization of Porcine Endogenous Retrovirus Clones from the NIH Miniature Pig BAC Library

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Seong-Lan Yu ◽  
Woo-Young Jung ◽  
Kie-Chul Jung ◽  
In-Cheol Cho ◽  
Hyun-Tae Lim ◽  
...  
Keyword(s):  
Bac Library ◽  
Endogenous Retrovirus ◽  
Endogenous Retroviruses ◽  
Miniature Pig ◽  
Reading Frame ◽  
Porcine Endogenous Retrovirus ◽  
Open Reading Frame Length ◽  
Porcine Endogenous Retroviruses ◽  
Integration Sites

Pigs have been considered as donors for xenotransplantation in the replacement of human organs and tissues. However, porcine endogenous retroviruses (PERVs) might transmit new infectious disease to humans during xenotransplantation. To investigate PERV integration sites, 45 PERV-positive BAC clones, including 12 PERV-A, 16 PERV-B, and 17 PERV-C clones, were identified from the NIH miniature pig BAC library. The analysis of 12 selected full-length sequences of PERVs, including the long terminal repeat (LTR) region, identified the expected of open reading frame length, an indicative of active PERV, in all five PERV-C clones and one of the four PERV-B clones. Premature stop codons were observed in only three PERV-A clones. Also, eleven PERV integration sites were mapped using a 5000-rad IMpRH panel. The map locations of PERV-C clones have not been reported before, thus they are novel PERV clones identified in this study. The results could provide basic information for the elimination of site-specific PERVs in selection of pigs for xenotransplantation.

scholarly journals Porcine Endogenous Retrovirus Transmission Characteristics of an Inbred Herd of Miniature Swine

2002 ◽  
Vol 76 (6) ◽  
pp. 3045-3048 ◽  
Author(s):  
Beth A. Oldmixon ◽  
James C. Wood ◽  
Thomas A. Ericsson ◽  
Carolyn A. Wilson ◽  
Mary E. White-Scharf ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Endogenous Retrovirus ◽  
Endogenous Retroviruses ◽  
Receptor Binding Domain ◽  
Transmission Characteristics ◽  
Miniature Swine ◽  
Recombinant Viruses ◽  
Porcine Endogenous Retrovirus ◽  
Porcine Endogenous Retroviruses

ABSTRACT Here we report the identification of inbred miniature swine that failed to produce human-tropic replication-competent porcine endogenous retroviruses (HTRC PERVs), using in vitro coculture assays. When HTRC PERVs were isolated from transmitting animals, all were recombinant viruses, with the receptor-binding domain of PERV-A combining with PERV-C-related sequences.

scholarly journals Identification of a novel type C porcine endogenous retrovirus: evidence that copy number of endogenous retroviruses increases during host inbreeding

2001 ◽  
Vol 82 (8) ◽  
pp. 1829-1834 ◽  
Author(s):  
Rui Mang ◽  
Jolanda Maas ◽  
Xianghong Chen ◽  
Jaap Goudsmit ◽  
Antoinette C. van der Kuyl
Keyword(s):  
Wild Boar ◽  
Copy Number ◽  
Endogenous Retrovirus ◽  
Endogenous Retroviruses ◽  
Human Endogenous Retrovirus ◽  
Porcine Endogenous Retrovirus ◽  
Porcine Endogenous Retroviruses ◽  
Pig Genome ◽  
Multiple Copies ◽  
Type C

Different classes of porcine endogenous retroviruses (PERVs), which have the potential to infect humans during xenotransplantation, have been isolated from the pig genome. Because vertebrate genomes may contain numerous endogenous retrovirus sequences, the pig genome was examined for additional endogenous retroviruses, resulting in the isolation of a novel, complete endogenous retrovirus genome, designated PERV-E. The gag, pol and env genes of PERV-E are closely related to those of human endogenous retrovirus (HERV) 4-1, which belongs to the HERV-E family. Results of studies to determine the presence and copy number of PERVs demonstrated that PERV-E and PERV-A/B-like proviruses were present in all genomes tested, but that PERV-C was not found in two of the species examined, including wild boar. Multiple copies of PERVs could be found in each pig genome. Among all of the pig genomes tested, the wild boar genome had the lowest copy number of all PERVs, suggesting that the number of integrations of complete endogenous retroviruses is increased by inbreeding.

scholarly journals Lack of antibody response in pigs immunized with the transmembrane envelope protein of porcine endogenous retroviruses

2014 ◽  
Vol 95 (8) ◽  
pp. 1827-1831 ◽  
Author(s):  
Martina Keller ◽  
Björn Petersen ◽  
Heiner Niemann ◽  
Joachim Denner
Keyword(s):  
Neutralizing Antibodies ◽  
Mammalian Species ◽  
Neutralization Assay ◽  
Endogenous Retrovirus ◽  
Proximal Region ◽  
Endogenous Retroviruses ◽  
Placental Development ◽  
Porcine Endogenous Retrovirus ◽  
Porcine Endogenous Retroviruses ◽  
Protein P15e

Recently, we immunized different mammalian species (goats, mice, rats, rabbits, guinea pigs and hamsters) with the recombinant ectodomain of the transmembrane envelope (TM) protein p15E of porcine endogenous retrovirus (PERV). In all cases, neutralizing immune sera were induced, which recognized epitopes in the fusion peptide proximal region and the membrane proximal external region of p15E. In order to analyse whether pigs are also able to produce such antibodies, and whether such antibodies can be used to study the involvement of the TM protein in placental development (as was shown for endogenous retroviruses of other species), German landrace pigs were immunized with PERV p15E. No binding and neutralizing antibodies were produced as shown in three Western blot analyses and in a neutralization assay, indicating that pigs are tolerant to their endogenous retroviruses, at least for the ectodomain of the TM protein.

scholarly journals Evolutionary Spread and Recombination of Porcine Endogenous Retroviruses in the Suiformes

2005 ◽  
Vol 79 (1) ◽  
pp. 649-654 ◽  
Author(s):  
Marcus Niebert ◽  
Ralf R. Tönjes
Keyword(s):  
Long Terminal Repeat ◽  
Related Species ◽  
Sus Scrofa ◽  
Endogenous Retroviruses ◽  
Phylogenetic Distance ◽  
African Origin ◽  
Closely Related Species ◽  
Separate Event ◽  
Porcine Endogenous Retroviruses ◽  
The Common

ABSTRACT Different Suiformes with increasing phylogenetic distance to the common pig (Sus scrofa) were assayed for the presence of porcine endogenous retroviruses (PERV) in general (pol gene), while the distribution of long terminal repeat (LTR) types (with or without repeats in U3) and env genes (classes A, B, and C) were determined in detail. PERV was not detectable in the most distantly related species, while classes PERV-A and PERV-B are present in Suiformes originating in the Pliocene epoch, and class PERV-C was detectable only in S. scrofa and in closely related species originating in the Holocene epoch. This distribution pattern of PERV classes is in line with our previous study on the age of PERV (45) and suggests an African origin of about 7.5 million years ago (MYA) and a gradual spread of PERV through the Suiformes. It seems likely that PERV-C originated more recently (1.5 to 3.5 MYA) by recombination with a homologue of unknown descent, while the origin of the repeatless LTR was a separate event approximately 3.5 MYA.

scholarly journals Identification of Novel Porcine Endogenous Betaretrovirus Sequences in Miniature Swine

2001 ◽  
Vol 75 (6) ◽  
pp. 2765-2770 ◽  
Author(s):  
Thomas Ericsson ◽  
Beth Oldmixon ◽  
Jonas Blomberg ◽  
Margaret Rosa ◽  
Clive Patience ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Bone Marrow Cells ◽  
Fetal Liver ◽  
Phylogenetic Analyses ◽  
Mammalian Species ◽  
Peripheral Blood Lymphocytes ◽  
Endogenous Retrovirus ◽  
Endogenous Retroviruses ◽  
Miniature Swine ◽  
Porcine Endogenous Retrovirus

ABSTRACT PCR amplification of genomic DNA from miniature swine peripheral blood lymphocytes, using primers corresponding to highly conserved regions of the polymerase (pol) gene, allowed the identification of two novel porcine endogenous retrovirus (PERV) sequences, PMSN-1 and PMSN-4. Phylogenetic analyses of the nucleotide sequences of PMSN-1 and PMSN-4 revealed them to be most closely related to betaretroviruses. The identification of PERVs belonging to theBetaretrovirus genus shows that endogenous retroviruses of this family are more broadly represented in mammalian species than previously appreciated. Both sequences contained inactivating mutations, implying that these particular loci are defective. However, Southern blot analysis showed additional copies of closely related proviruses in the miniature swine genome. Analyses of fetal and adult miniature swine tissues revealed a broad mRNA expression pattern of both PMSN-1 and PMSN-4. The most abundant expression was detected in whole bone marrow c-kit +(CD117+) progenitor bone marrow cells, fetal liver, salivary gland, and thymus. It appears unlikely that functional loci encoding these novel PERV sequences exist, but this remains to be established. The betaretrovirus sequences described in this report will allow such investigations to be actively pursued.

scholarly journals Identification of a Full-Length cDNA for an Endogenous Retrovirus of Miniature Swine

1998 ◽  
Vol 72 (5) ◽  
pp. 4503-4507 ◽  
Author(s):  
Donna E. Akiyoshi ◽  
Maria Denaro ◽  
Haihong Zhu ◽  
Julia L. Greenstein ◽  
Papia Banerjee ◽  
...  
Keyword(s):  
Amino Acid ◽  
Leukemia Virus ◽  
Endogenous Retrovirus ◽  
Amino Acid Sequences ◽  
Full Length ◽  
Endogenous Retroviruses ◽  
Miniature Swine ◽  
Sequence Identity ◽  
Multiple Organs ◽  
Porcine Endogenous Retrovirus

ABSTRACT Endogenous retroviruses of swine are a concern in the use of pig-derived tissues for xenotransplantation into humans. The nucleotide sequence of porcine endogenous retrovirus taken from lymphocytes of miniature swine (PERV-MSL) has been characterized. PERV-MSL is a type C retrovirus of 8,132 bp with the greatest nucleic acid sequence identity to gibbon ape leukemia virus and murine leukemia virus. Constitutive production of PERV-MSL RNA has been detected in normal leukocytes and in multiple organs of swine. The copy numbers of full-length PERV sequences per genome (approximately 8 to 15) vary among swine strains. The open reading frames for gag, pol, andenv in PERV-MSL have over 99% amino acid sequence identity to those of Tsukuba-1 retrovirus and are highly homologous to those of endogenous retrovirus of cell line PK15 (PK15-ERV). Most of the differences in the predicted amino acid sequences of PK15-ERV and PERV-MSL are in the SU (cell attach- ment) region ofenv. The existence of these PERV clones will enable studies of infection by endogenous retroviruses in xenotransplantation.

scholarly journals The Relationship between Embryonic Development and the Efficiency of Target Mutations in Porcine Endogenous Retroviruses (PERVs) Pol Genes in Porcine Embryos

Animals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 593 ◽  
Author(s):  
Maki Hirata ◽  
Manita Wittayarat ◽  
Takayuki Hirano ◽  
Nhien Thi Nguyen ◽  
Quynh Anh Le ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Genome Editing ◽  
Endogenous Retrovirus ◽  
Endogenous Retroviruses ◽  
Cell Stage ◽  
Gene Target ◽  
Porcine Endogenous Retrovirus ◽  
Cas9 Protein ◽  
Pig Genome ◽  
The Relationship

Porcine endogenous retrovirus (PERV) is a provirus found in the pig genome that may act as an infectious pathogen in humans who receive pig organ xenotransplantation. Inactivation of the PERV pol gene in porcine cells reportedly affects cell growth. Therefore, the mutation of PERV pol gene in porcine embryos using genome editing may affect the embryonic development. The present study was carried out to investigate the relationship between the mutation of the PERV pol gene in porcine embryos and their development. We introduced, either alone or in combination, three different gRNAs (gRNA1, 2, and 3) into porcine zygotes by genome editing using electroporation of the Cas9 protein (GEEP) system. All three gRNAs targeted the PERV pol gene, and we assessed their effects on porcine embryonic development. Our results showed that the blastocyst formation rates of zygotes electroporated with gRNA3—alone and in combination—were significantly lower (p < 0.05) than those of zygotes electroporated with gRNA1. The mutation rates assessed by the PERV pol gene target site sequencing in individual blastocysts and pooled embryos at the 2-to-8-cell stage did not differ among the three gRNAs. However, the frequency of indel mutations in mutant embryos at the 2-to-8-cell stage trended higher in the embryos electroporated with gRNA3 alone and in combination. Embryonic development may be affected by gRNAs that induce high-frequency indel mutations.

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