Genomic integration of bovine leukaemia provirus: comparison between persistent lymphocytosis and lymph node tumour form of enzootic bovine leukosis.

We report the complete 8714-nucleotide sequence of the integrated bovine leukemia virus genome and deduce the following genomic organization: 5' LTR-gag-pol-env-pXBL-3' LTR, where LTR represents a long terminal repeat and pXBL represents a region containing unidentified open reading frames. This genomic structure is similar to that of human T-cell leukemia virus. The LTR contains a putative splice donor site in the R region. The gag gene encodes a precursor protein with the form NH2-p15-p24-p12-COOH. The NH2- and COOH-terminal regions of the pol product show stronger homologies with those of avian, rather than murine, type C retrovirus, and its structure is identical to that of avian virus. The env gene encodes a surface glycoprotein (gp51) and a transmembrane protein (gp30). In contrast to the pol product, the gp30 shows stronger sequence homology with a murine, rather than avian homologue, indicating the chimeric nature of the bovine leukemia virus genome. Comparisons of the best conserved pol sequences and overall genomic organizations between several major oncoviruses allow us to propose that bovine leukemia and human T-cell leukemia viruses constitute a group, designated as type "E," of Oncovirinae.

Bovine leukemia virus

Genomic Organization

Homology

Conserved sequence

10.1073/pnas.82.3.677

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Citations (451)

Leukemogenesis by bovine leukemia virus: proviral DNA integration and lack of RNA expression of viral long terminal repeat and 3' proximate cellular sequences.

Proceedings of the National Academy of Sciences (1982)

R. Kettmann Jacqueline Deschamps Y. Cleuter Dominique Couez Arsène Burny

The DNA from 17 lymphoid tumors induced by bovine leukemia virus (BLV) was digested with the restriction endonuclease EcoRI. Filter hybridization analysis using radioactive probes specific for the BLV genome showed that all tumors contained at least one or a portion of one provirus. Digestion of these proviruses with Sac I demonstrated that deletions occurred in about 25% of the cases and involved sequences located in the 5' half of the provirus. No sequence homology was observed between the cloned proximate cellular sequences flanking two different proviruses at their 3' end and the corresponding sequences in 16 other tumor DNAs, thus showing that a wide range of genomic sites could accommodate BLV proviruses. Transcription of viral DNA including long terminal repeated sequences was not detected, strongly suggesting that viral gene expression is not required for maintenance of the tumor state. No expression of 3'-proximate cellular sequences was observed, indicating that no proximate downstream promotion took place in the cases examined.

Provirus

Bovine leukemia virus

Restriction map

10.1073/pnas.79.8.2465

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Citations (157)

Bergapten apoptosis induction in blood lymphocytes of cattle infected with bovine leukaemia virus [BLV]

Bulletin of the Veterinary Institute in Pulawy (2004)

Anna Bogucka‐Kocka J. Rułka Janusz Kocki P. Kubis E. Buzała

Bergapten

Bovine leukemia virus

Source