scholarly journals Molecular Cloning and Functional Analysis of Three Type D Endogenous Retroviruses of Sheep Reveal a Different Cell Tropism from That of the Highly Related Exogenous Jaagsiekte Sheep Retrovirus

2000 ◽  
Vol 74 (17) ◽  
pp. 8065-8076 ◽  
Author(s):  
Massimo Palmarini ◽  
Claus Hallwirth ◽  
Denis York ◽  
Claudio Murgia ◽  
Tulio de Oliveira ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Endogenous Retroviruses ◽  
Open Reading Frames ◽  
Lung Epithelial Cells ◽  
Structural Genes ◽  
Jaagsiekte Sheep Retrovirus ◽  
Type D ◽  
Viral Particles ◽  
Reading Frames

ABSTRACT Integrated into the sheep genome are 15 to 20 copies of type D endogenous loci that are highly related to two exogenous oncogenic viruses, jaagsiekte sheep retrovirus (JSRV) and enzootic nasal tumor virus (ENTV). The exogenous viruses cause infectious neoplasms of the respiratory tract in small ruminants. In this study, we molecularly cloned three intact type D endogenous retroviruses of sheep (enJS56A1, enJS5F16, and enJS59A1; collectively called enJRSVs) and analyzed their genomic structures, their phylogenies with respect to their exogenous counterparts, their capacity to form viral particles, and the expression specificities of their long terminal repeats (LTRs). In addition, the pattern of expression of enJSRVs in vivo was studied by in situ hybridization. All of the threeenJSRV proviruses had open reading frames for at least one of the structural genes. In particular, enJS56A1 had open reading frames for all structural genes, but it could not assemble viral particles when highly expressed in human 293T cells. We localized the defect for viral assembly in the first two-thirds of thegag gene by making a series of chimeras between enJS56A1 and the exogenous infectious molecular clone JSRV21. Phylogenetic analysis distinguished five ovine type D retroviruses:enJSRV groups A and B, ENTV, and two exogenous JSRV groups (African versus United Kingdom/North America isolates). Transient transfection assays indicated that the LTRs of the threeenJSRVs were not preferentially active in differentiated lung epithelial cells. This suggests that the pulmonary tropic JSRV developed from a type D retrovirus that did not have lung specificity. Consistent with this, in situ hybridization of a panel of normal ovine tissues revealed high expression of enJSRV mRNA in the luminal epithelium and glandular epithelium of the uterus; lower expression was localized in the lamina propria of the gut and in the bronchiolar epithelium of the lungs.

scholarly journals Ancient Adversary – HERV-K (HML-2) in Cancer

2021 ◽  
Vol 11 ◽  
Author(s):  
Eoin Dervan ◽  
Dibyangana D. Bhattacharyya ◽  
Jake D. McAuliffe ◽  
Faizan H. Khan ◽  
Sharon A. Glynn
Keyword(s):  
Tumour Progression ◽  
Endogenous Retroviruses ◽  
Open Reading Frames ◽  
Human Endogenous Retroviruses ◽  
Viral Particles ◽  
Metastatic Capacity ◽  
Coding Capacity ◽  
Reading Frames

Human endogenous retroviruses (HERV), ancient integrations of exogenous viruses, make up 8% of our genome. Long thought of as mere vestigial genetic elements, evidence is now accumulating to suggest a potential functional role in numerous pathologies including neurodegenerative diseases, autoimmune disorders, and multiple cancers. The youngest member of this group of transposable elements is HERV-K (HML-2). Like the majority of HERV sequences, significant post-insertional mutations have disarmed HERV-K (HML-2), preventing it from producing infectious viral particles. However, some insertions have retained limited coding capacity, and complete open reading frames for all its constituent proteins can be found throughout the genome. For this reason HERV-K (HML-2) has garnered more attention than its peers. The tight epigenetic control thought to suppress expression in healthy tissue is lost during carcinogenesis. Upregulation of HERV-K (HML-2) derived mRNA and protein has been reported in a variety of solid and liquid tumour types, and while causality has yet to be established, progressively more data are emerging to suggest this phenomenon may contribute to tumour growth and metastatic capacity. Herein we discuss its potential utility as a diagnostic tool and therapeutic target in light of the current in vitro, in vivo and clinical evidence linking HERV-K (HML-2) to tumour progression.

scholarly journals Systematic Identification of Endogenous Retroviral Protein-Coding Genes Expressed in Canine Oral Malignant Melanoma

2021 ◽  
Vol 1 ◽  
Author(s):  
Koichi Kitao ◽  
Aoi Sumiyoshi ◽  
So Nakagawa ◽  
Yuki Matsumoto ◽  
Takuya Mizuno ◽  
...  
Keyword(s):  
Malignant Melanoma ◽  
Endogenous Retroviruses ◽  
Open Reading Frames ◽  
Protein Coding ◽  
Differential Expression Gene ◽  
Viral Particles ◽  
Oral Malignant Melanoma ◽  
Env Protein ◽  
Systematic Identification ◽  
Reading Frames

Endogenous retroviruses (ERVs) are remnants of ancestral retroviruses that infected host germ cells in the past. Most ERVs are thought to be non-functional elements, but some ERVs retain open reading frames (ORFs) capable of expressing proteins. The proteins encoded by ERV-ORFs have potential roles in oncogenesis; however, studies on mammals other than humans and mice are limited. Here, we identified ERV-derived genes expressed in canine oral malignant melanoma (OMM). We identified 11 ERV-derived genes in our OMM samples. Differential expression gene analysis revealed that four ERV-derived genes (PEG10, LOC102155597, and two newly identified genes) were upregulated in OMM compared to healthy tissues. PEG10 is a conserved long terminal repeat (LTR)-type retrotransposon-derived gene among mammals and is involved in human cancers. LOC102155597 is a retroviral env gene conserved in Carnivora. This Env protein harbors an immunosuppressive domain, implying the potential adverse effects on the immune system. While the production of viral particles from ERVs has been reported in human and mouse melanoma, we found no ERV-derived genes having the potential to produce viral particles. These results provide insights into the different and conserved features of ERV-derived genes in mammalian melanoma.

scholarly journals Detection and Confirmation of Reptilian Adenovirus Infection by in Situ Hybridization

2001 ◽  
Vol 13 (4) ◽  
pp. 365-368 ◽  
Author(s):  
Laura E. Leigh Perkins ◽  
Raymond P. Campagnoli ◽  
Barry G. Harmon ◽  
Christopher R. Gregory ◽  
W. L. Steffens ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
In Situ Hybridization ◽  
Adenovirus Infection ◽  
Pathogenic Potential ◽  
Suitable Alternative ◽  
Viral Particles ◽  
Viral Inclusions ◽  
Diagnostic Setting ◽  
Formalin Fixed

Adenovirus infections are documented in at least 12 different species of reptiles. In contrast to their mammalian and avian counterparts reptilian adenoviruses are not well characterized as to their pathogenic potential and their ability to cause primary disease. In the diagnostic setting, fresh tissues are often not available for virus isolation, and the confirmation of reptilian adenovirus infections is dependent largely upon electron microscopy for the identification of intranuclear viral inclusions associated with histopathologic changes. The diagnosis of adenovirus infection in 2 different species of snake was confirmed by the application of DNA in situ hybridization. Using an aviadenovirus specific oligoprobe, adenoviral DNA was observed in the nuclei of hepatocytes, Kupffer cells, endothelial cells, and enterocytes. Electron microscopy of the liver confirmed the presence of intranuclear viral particles morphologically consistent with an adenovirus. DNA in situ hybridization on formalin-fixed tissues can serve as a suitable alternative to electron microscopy in the diagnosis of reptilian adenovirus infections. Both affected snakes had other concurrent diseases, suggesting that the adenovirus may not have been the primary pathogen.

scholarly journals Characterization of Endogenous Retroviruses in Sheep

2003 ◽  
Vol 77 (20) ◽  
pp. 11268-11273 ◽  
Author(s):  
Nikolai Klymiuk ◽  
Mathias Müller ◽  
Gottfried Brem ◽  
Bernhard Aigner
Keyword(s):  
Endogenous Retrovirus ◽  
Ovis Aries ◽  
Endogenous Retroviruses ◽  
Open Reading Frames ◽  
In Vivo Experiments ◽  
Pregnant Sheep ◽  
Reading Frames

ABSTRACT Endogenous retrovirus (ERV) sequences have been found in all mammals. In vitro and in vivo experiments revealed ERV activation and cross-species infection in several species. Sheep (Ovis aries) are used for various biotechnological purposes; however, they have not yet been comprehensively screened for ERV sequences. Therefore, the aim of the study was to classify the ERV sequences in the ovine genome (OERV) by analyzing the retroviral pro-pol sequences. Three OERV β families and nine OERV γ families were revealed. Novel open reading frames (ORF) in the amplified proviral fragment were found in one OERV β family and two OERV γ families. Hybrid OERV produced by putative recombination events were not detected. Quantitative analysis of the OERV sequences in the ovine genome revealed no relevant variations in the endogenous retroviral loads of different breeds. Expression analysis of different tissues from fetal and pregnant sheep detected mRNA from both gammaretrovirus families, showing ORF fragments. Thus, the release of retroviruses from sheep cells cannot be excluded.

EXPLORING THE CHRONIC MORTALITY AFFECTING ABALONES IN TAIWAN: DIFFERENTIATION OF ABALONE HERPESVIRUS-ASSOCIATED ACUTE INFECTION FROM CHRONIC MORTALITY BY PCR AND IN SITU HYBRIDIZATION AND HISTOPATHOLOGY

2016 ◽  
Vol 42 (01) ◽  
pp. 1-9 ◽  
Author(s):  
I-Wen Chen ◽  
Pen-Heng Chang ◽  
Min-Shou Chen ◽  
Tristan Renault ◽  
Meei-Mei Chen ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Acute Infection ◽  
Extended Period ◽  
Haliotis Diversicolor Supertexta ◽  
Transmission Electron ◽  
Viral Particles ◽  
Primer Sets ◽  
Diversicolor Supertexta ◽  
Pcr In Situ

Abalone herpesvirus (AbHV) infection of cultured abalones Haliotis diversicolor supertexta induced acute high mortality in 2003. Years later, sporadic mortality was noted for an extended period of months, resulting in high cumulative mortality. Moribund abalones were analyzed using PCR, in situ hybridization, and histopathology, because thus far no viral particles have been observed by transmission electron microscopy. PCR using 20 primer sets, specifically designed from sequences of acute AbHV infection, failed to amplify any products from abalones suffering from chronic mortality. Subsequently, a 1406-bp sequence was amplified from chronic moribund abalones, and this sequence showed a 92% (553 bp/602 bp) homology with the gene of an AbHV Taiwan isolate (NCBI serial no. KF537536.1), suggestive of an AbHV pathotype. Histopathology of AbHV pathotype infection showed hemocyte infiltration in the lamina propia of the digestive tract, and hemocytes of various stages were evident, as well as the loss of seminal tubules in the gonad. In situ hybridization revealed that in AbHV infection, positive signals were restricted to the neural ganglia, while in AbHV pathotype infection, positive signals were observed only in the hemocytes. It appeared that the tropism of AbHV shifted from mainly neurotropic in AbHV infection to mainly hemocytotropic in abalone suffering from chronic mortality. Abalone shriveling syndrome-associated virus co-infection was detected in some of AbHV pathotype infection events. Further studies are needed to better understand the pathogenesis of AbHV pathotype affecting H. diversicolor in Taiwan.

scholarly journals Genome Structure and Thymic Expression of an Endogenous Retrovirus in Zebrafish

2004 ◽  
Vol 78 (2) ◽  
pp. 899-911 ◽  
Author(s):  
Ching-Hung Shen ◽  
Lisa A. Steiner
Keyword(s):  
Leukemia Virus ◽  
Genome Structure ◽  
Endogenous Retrovirus ◽  
Northern Blotting ◽  
Open Reading Frames ◽  
Genomic Locus ◽  
Dna Libraries ◽  
Adult Thymus ◽  
Reading Frames

ABSTRACT In a search for previously unknown genes that are required for lymphocyte development in zebrafish, a retroviral sequence was identified in a subtracted thymus cDNA library and in genomic DNA libraries. The provirus is 11.2 kb and contains intact open reading frames for the gag, pol, and env genes, as well as nearly identical flanking long terminal repeat sequences. As determined by in situ hybridization, the thymus appears to be a major tissue for retroviral expression in both larval and adult fish. Several viral transcripts were found by Northern blotting in the adult thymus. The provirus was found at the same genomic locus in sperm from four fish, suggesting that it is an endogenous retrovirus. Phylogenetic analysis indicates that it is closest to, yet distinct from, the cluster of murine leukemia virus-related retroviruses, suggesting that this virus represents a new group of retroviruses.

scholarly journals Molecular Characterization and Placental Expression of HERV-W, a New Human Endogenous Retrovirus Family

1999 ◽  
Vol 73 (2) ◽  
pp. 1175-1185 ◽  
Author(s):  
Jean-Luc Blond ◽  
Frédéric Besème ◽  
Laurent Duret ◽  
Olivier Bouton ◽  
Frédéric Bedin ◽  
...  
Keyword(s):  
Endogenous Retrovirus ◽  
Endogenous Retroviruses ◽  
Open Reading Frames ◽  
Primer Binding Site ◽  
Human Endogenous Retrovirus ◽  
Cdna Clones ◽  
Human Endogenous Retroviruses ◽  
Herv Family ◽  
Flanking Sequences ◽  
Reading Frames

ABSTRACT The multiple sclerosis-associated retrovirus (MSRV) isolated from plasma of MS patients was found to be phylogenetically and experimentally related to human endogenous retroviruses (HERVs). To characterize the MSRV-related HERV family and to test the hypothesis of a replication-competent HERV, we have investigated the expression of MSRV-related sequences in healthy tissues. The expression of MSRV-related transcripts restricted to the placenta led to the isolation of overlapping cDNA clones from a cDNA library. These cDNAs spanned a 7.6-kb region containing gag, pol, and env genes; RU5 and U3R flanking sequences; a polypurine tract; and a primer binding site (PBS). As this PBS showed similarity to avian retrovirus PBSs used by tRNATrp, this new HERV family was named HERV-W. Several genomic elements were identified, one of them containing a complete HERV-W unit, spanning all cDNA clones. Elements of this multicopy family were not replication competent, asgag and pol open reading frames (ORFs) were interrupted by frameshifts and stop codons. A complete ORF putatively coding for an envelope protein was found both on the HERV-W DNA prototype and within an RU5-env-U3R polyadenylated cDNA clone. Placental expression of 8-, 3.1-, and 1.3-kb transcripts was observed, and a putative splicing strategy was described. The apparently tissue-restricted HERV-W long terminal repeat expression is discussed with respect to physiological and pathological contexts.

scholarly journals Comparison of novel GH 68 levansucrases of levan-overproducing Gluconobacter species

2012 ◽  
Vol 1 (1) ◽  
pp. 2 ◽  
Author(s):  
Frank Jakob ◽  
Daniel Meißner ◽  
Rudi F. Vogel
Keyword(s):  
Open Reading Frames ◽  
Ex Situ ◽  
Inverse Pcr ◽  
E Coli ◽  
Food Biotechnology ◽  
Food Applications ◽  
Pcr Techniques ◽  
Single Primer ◽  
Reading Frames

<em>Gluconobacter</em> species are capable of incomplete oxidations which are exploited in food biotechnology. Levans isolated from exopolysaccharide (EPS)-overproducing <em>Gluconobacter</em> species are promising functional compounds for food applications. Fructan production strongly depends on the corresponding fructosyltransferases (Ftfs), which catalyze the formation of these polymers from sucrose. Therefore, we characterized novel Ftfs from three EPS-overproducing food-grade strains, i.e. <em>Gluconobacter</em> sp. TMW 2.767 and <em>Gluconobacter</em> sp. TMW 2.1191 isolated from water kefir, and <em>Gluconobacter cerinus</em> DSM 9533T isolated from cherries. Several PCR techniques, including degenerate gradient temperature PCR, modified and standard inverse PCR, modified site-finding PCR and modified single primer PCR, were used to finally detect complete open reading frames coding for Ftfs. The prospective ftf-gene sequences were heterologously expressed in <em>Escherichia coli</em> Top 10. <em>E. coli</em> transformants harboring one of the three different ftf-genes produced polysaccharides from sucrose in contrast to the <em>E. coli</em> wildtype. Each of the heterologously expressed proteins encoded a levansucrase, catalyzing the formation of b-(2&rarr;6)-linked fructose polymers, which corresponded to our previous analyses about the chemical nature of the isolated polymers formed by these <em>Gluconobacter</em> strains. Structurally, these enzymes belong to the glycoside hydrolase 68 family (GH 68), sharing the typical modular topology of levansucrases from gram-negative bacteria. In conclusion, we could identify novel active levansucrases, which can be used for <em>ex situ</em> (enzymatic catalyses) or <em>in situ</em> (fermentation) production of functional fructan polymers by <em>Gluconobacter</em> strains in food and other applications.

scholarly journals HIV-particles in spermatozoa of patients with AIDS and their transfer into the oocyte

1994 ◽  
Vol 127 (4) ◽  
pp. 903-914 ◽  
Author(s):  
B Baccetti ◽  
A Benedetto ◽  
AG Burrini ◽  
G Collodel ◽  
EC Ceccarini ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
In Situ Hybridization ◽  
Present Evidence ◽  
Electron Microscopy Level ◽  
Normal Sperm ◽  
Viral Particles ◽  
Normal Human ◽  
Sperm Membrane ◽  
Hiv 1

By immunocytochemistry and in situ hybridization at the electron microscopy level, and by the PCR technique, we have shown that HIV-1 binds and enters normal sperm; that viral particles, their antigens, and nucleic acid are present in sperm from HIV-1 infected men; and that such sperm can transfer HIV-1 like particles to normal human oocytes. We also present evidence that a galactosylceramide-like compound is present on the sperm membrane and could function as an alternative receptor for HIV.

scholarly journals Structural analysis of TRAS1, a novel family of telomeric repeat-associated retrotransposons in the silkworm, Bombyx mori.

1995 ◽  
Vol 15 (8) ◽  
pp. 4545-4552 ◽  
Author(s):  
S Okazaki ◽  
H Ishikawa ◽  
H Fujiwara
Keyword(s):  
Bombyx Mori ◽  
Repetitive Sequence ◽  
Repetitive Sequences ◽  
Complete Sequence ◽  
Open Reading Frames ◽  
Ltr Retrotransposons ◽  
Reading Frames ◽  
28S Ribosomal Dna ◽  
Silkworm Bombyx Mori

We characterized TRAS1, a retrotransposable element which was inserted into the telomeric repetitive sequence (CCTAA)n of the silkworm, Bombyx mori. The complete sequence of TRAS1, a stretch of 7.8 kb with a poly(A) tract at the 3' end, was determined. No long terminal repeat (LTR) was found at the termini of the element. TRAS1 contains gag- and pol-like open reading frames (ORFs) which are similar to those of non-LTR retrotransposons. The two ORFs overlap but are one nucleotide out of frame (+1 frameshift). Most of the approximately 250 copies of TRAS1 elements in the genome were highly conserved in the structure. Chromosomal in situ hybridization showed that TRAS1 elements are clustered at the telomeres of Bombyx chromosomes. A phylogenetic analysis using the amino acid sequence of the reverse transcriptase domain within the pol-like ORF revealed that TRAS1 falls into one lineage with R1, which is a family of non-LTR retrotransposons inserted into the same site within the 28S ribosomal DNA unit in most insects. TRAS1 may have been derived from R1 and changed the target specificity so that TRAS1 inserts into the telomeric repetitive sequence (CCTAA)n. Southern hybridization and Bal 31 exonuclease analyses showed that TRAS1 elements are clustered proximal to the terminal long tract of (CCTAA)n. TRAS1 is a novel family of non-LTR retrotransposons which are inserted into the telomeric repetitive sequences as target sites.

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