The nucleotide sequence of the env gene and post-env region of bovine leukemia virus

Rice, Nancy R.; Stephens, Robert M.; Couez, Dominique; Deschamps, Jacqueline; Kettmann, Richard; Burny, Arsène; Gilden, R. V.

doi:10.1016/0042-6822(84)90149-1

Cited by 143 publications

(93 citation statements)

References 23 publications

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“…The 28 BLV env sequences from Argentina were combined with 46 BLV env sequences obtained from GenBank (Supplementary Table S1). Representatives of all the sequence groupings identified previously were included in the GenBank sequences selected (Camargos et al, 2002(Camargos et al, , 2007Coulston et al, 1990;Dube et al, 2000;Hemmatzadeh, 2007;Mamoun et al, 1990;Molteni et al, 1996;Rice et al, 1984;Sagata et al, 1985;Willems et al, 1993;Zhao & Buehring, 2007). Prior to phylogenetic analysis, the sequences were aligned using the MAFFT program (Katoh et al, 2002(Katoh et al, , 2005 and the resulting alignment was inspected using the genetic data environment (GDE) program (Eisen, 1997;Smith et al, 1994) and further checked with the CLUSTAL_X program (Thompson et al, 2002).…”

Section: Methodsmentioning

confidence: 99%

Bovine leukemia virus can be classified into seven genotypes: evidence for the existence of two novel clades

Rodríguez¹,

Golemba²,

Campos³

et al. 2009

Journal of General Virology

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Previous studies have classified the env sequences of bovine leukemia virus (BLV) provirus from different locations worldwide into between two and four genetic groupings. These different studies gave unique names to the identified groups and no study has yet integrated all the available sequences. Thus, we hypothesized that many of the different groups previously identified actually correspond to a limited group of genotypes that are unevenly distributed worldwide. To examine this hypothesis, we sequenced the env gene from 28 BLV field strains and compared these sequences to 46 env sequences that represent all the genetic groupings already identified. By using phylogenetic analyses, we recovered six clades, or genotypes, that we have called genotypes 1, 2, 3, 4, 5 and 6. Genotypes 1-5 have counterparts among the sequence groupings identified previously. One env sequence did not cluster with any of the others and was highly divergent when compared with the six genotypes identified here. Thus, an extra genotype, which we named 7, may exist. Similarity comparisons were highly congruent with phylogenetic analyses. Furthermore, our analyses confirmed the existence of geographical clusters. INTRODUCTIONBovine leukemia virus (BLV) is a member of the family Retroviridae belonging to the genus Deltaretrovirus. This genus also includes Simian T-lymphotropic virus 1, 2, 3 and 5 (STLV-1, -2, -3 and -5) and Human T-lymphotropic virus 1, 2, 3 and 4 (HTLV-1, -2, -3 and -4). have not yet been associated with any pathology, likely due to their recent identification and to the low number of isolates. Therefore, BLV is considered a model of HTLV-1 and -2 . BLV is recognized as the aetiological agent of enzootic bovine leukosis, a disease that results in significant economic losses for the worldwide cattle industry. The most conspicuous clinical manifestation of bovine leukosis, which only develops in a small fraction of infected animals, is the clonal expansion and local accumulation of B cells that results in the development of lymphoid tumours (lymphosarcoma, LS) (Gillet et al., 2007). The majority of infections are not associated with any clinical signs (AL), and in approximately 30 % of infected cattle, the virus causes a persistent lymphocytosis (PL) (Burny et al., 1987;Mirsky et al., 1996).Analyses of the BLV envelope (env) gene of isolates collected in multiple geographical locations demonstrated significant sequence conservation (Camargos et al., 2002(Camargos et al., , 2007Coulston et al., 1990). Nevertheless, up to seven BLV genotypes can be identified by RFLP analysis (Asfaw et al., 2005;Coulston et al., 1990;Fechner et al., 1997;Kettmann et al., 1981;Licursi et al., 2002). Furthermore, the env sequences of the BLV provirus from different locations worldwide have previously been classified into between two and four genetic groupings (Camargos et al., 2002(Camargos et al., , 2007Felmer et al., 2005;Hemmatzadeh, 2007;Licursi et al., 2003;Mamoun et al., 1990;Monti et al., 2005;Zhao & Buehring, 2007), with similar results...

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Section: Methodsmentioning

confidence: 99%

Bovine leukemia virus can be classified into seven genotypes: evidence for the existence of two novel clades

Rodríguez¹,

Golemba²,

Campos³

et al. 2009

Journal of General Virology

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“…35 Primers corresponding to the env and ltr genes were selected because this region is highly conserved among different BLV provirus isolates. 33 Forward primers were env5032 5Ј-TCT GTG CCA AGT CTC CCA GAT A-3Ј and env5099 5Ј-CCC ACA AGG GCG GCG CCG GTT T-3Ј. The reverse primers were env5521r 5Ј-GCG AGG CCG GGT CCA GAG CTG G-3Ј and env5608r 5Ј-AAC AAC AAC CTC TGG GAA GGG T-3Ј.…”

Section: Proviral Detection By Nested Pcrmentioning

confidence: 99%

Evaluation of a New Antibody-Based Enzyme-Linked Immunosorbent Assay for the Detection of Bovine Leukemia Virus Infection in Dairy Cattle

et al. 2005

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Abstract. The objective of this study was to validate a new blocking enzyme-linked immunosorbent assay (ELISA) (designated M108 for milk and S108 for serum samples) for detecting bovine leukemia virus (BLV) infection in dairy cattle. Milk, serum, and ethylenediaminetetraacetic acid-blood samples were collected from 524 adult Holstein cows originating from 6 dairy herds in Central Argentina. The M108 and S108 were compared with agar gel immunodiffusion (AGID), polymerase chain reaction and a commercial ELISA. Because there is currently no reference test capable of serving as a gold standard, the test sensitivity (SE) and specificity (SP) were evaluated by the use of a latent class model. Statistical inference was performed by classical maximum likelihood and by Bayesian techniques. The maximum-likelihood analysis was performed assuming conditional independence of tests, whereas the Bayesian approach allowed for conditional dependence. No clear conclusion could be drawn about conditional dependence of tests. Results with maximum likelihood (under conditional independence) and posterior Bayes (under conditional dependence) were practically the same. Conservative estimates of SE and SP (with 95% confidence intervals) for M108 were 98.6 (96.7; 99.6) and 96.7 (92.9; 98.8) and for S108 99.5 (98.2; 99.9) and 95.4 (90.9; 98.1), respectively. The ELISA 108 using either milk or serum to detect BLV-infected animals had comparable SE and SP with the official AGID and a commercial ELISA test, which are currently the most widely accepted tests for the serological diagnosis of BLV infection. Therefore, ELISA 108 can be used as an alternative test in monitoring and control programs.

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“…Its genome contains the classical structural genes (gag, pol and env) coding, respectively, for the viral capsid, the RNA-dependent DNA polymerase (the reverse transcriptase) and the envelope (Figure 2). A series of other open reading frames at the 3'-end of the genome encode regulatory proteins: Tax, Rex, R3 and G4 (15)(16)(17)(18)(19)(20)(21)(22). Tax and Rex are essential proteins required for transcriptional and post-transcriptional activation of viral expression.…”

Section: Introductionmentioning

confidence: 99%

Cell dynamics and immune response to BLV infection: a unifying model

Florins¹

2007

Front Biosci

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The nucleotide sequence of the env gene and post-env region of bovine leukemia virus

Cited by 143 publications

References 23 publications

Bovine leukemia virus can be classified into seven genotypes: evidence for the existence of two novel clades

Bovine leukemia virus can be classified into seven genotypes: evidence for the existence of two novel clades

Evaluation of a New Antibody-Based Enzyme-Linked Immunosorbent Assay for the Detection of Bovine Leukemia Virus Infection in Dairy Cattle

Cell dynamics and immune response to BLV infection: a unifying model

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