Disease relevance of pol

• The sequence variation in small ruminant lentiviruses from Brazilian herds of milking goats was sampled in a representative region of the pol gene and in a region including the entire tat open reading frame [1].
• Since the MVV peptide was not recognised by antibodies or T lymphocytes from MVV-infected and encephalic sheep, it was concluded that epitope mimicry of this 21.5 kDa MBP peptide by the similar MVV pol peptide was not contributing to the immunopathogensis of Visna [2].
• Primers were designed from the pol gene conserved motifs of 85 SRLV isolates and were evaluated using different SRLV isolates together with Maedi-Visna virus (MVV) and caprine arthritis-encephalitis virus (CAEV) reference strains [3].
• Evolutionary trees of the proviral 597 nucleotide gag and 432 nucleotide pol sequences obtained by the maximum likelihood method demonstrated that the sheep isolate clustered with prototype Maedi Visna virus whereas three lentiviruses isolated from goats in the same geographic region were close to caprine arthritis encephalitis prototypes [4].

High impact information on pol

• The two smallest transcripts (1.8 and 1.5 kb) are at least doubly spliced mRNAs which contain sequences derived from the 5' end of the genome, the region between the pol and env genes, and 3' terminal sequences [5].
• These data demonstrated that the greatest overall conservation of nucleotide sequences occurred in the gag and pol gene regions and two smaller regions, sor and the putative tat gene [6].
• Clones were amplified from cDNA derived from virus produced in vitro using primers targetting conserved sequences of the pol gene [1].
• Based on available sequence data, a phylogeny of small ruminant lentiviruses (SRLV) was established for env, pol, gag and LTR fragments using maximum likelihood, neighbour-joining and minimum evolution reconstruction techniques [7].
• Open reading frames for gag and pol genes were identified and their sequences matched very closely to those determined previously by others [8].

Biological context of pol

• To contribute to this knowledge, gag, pol, and env nucleotide sequences from an SRLV named CA680 originating from a goat from western France were determined [9].
• However, in the present study, the pol gene reading frame was open throughout its entire length [8].
• The pol and gag gene fragments of small ruminant lentivirus field isolates collected in the last decade in Italy were amplified, sequenced, and analyzed [10].

Anatomical context of pol

• Weise and Carnegie (1988) found a region of sequence similarity between the pol gene of the Maedi Visna virus (MVV), which induces demyelinating encephalitis in sheep, and myelin basic protein (MBP), which is known to induce experimental allergic encephalitis (EAE) in laboratory animals [2].

Associations of pol with chemical compounds

• The genome of MVV includes three genes: gag, which encodes for group-specific antigens; pol, which encodes for reverse transcriptase, integrase, RNAse H, protease and dUTPase and env, the gene encoding for the surface glycoprotein responsible for receptor binding and entry of the virus into its host cell [11].

Analytical, diagnostic and therapeutic context of pol

• To test this hypothesis, SRLV pol sequences were obtained by PCR amplification from blood samples of seropositive dairy goats and sheep living in mixed flocks [12].
• In order to determine the genomic heterogeneity of ovine lentiviruses, we analysed eight isolates from naturally infected sheep from one geographical region of France. A 475 nt fragment in the region of the pol gene coding for reverse transcriptase was amplified by RT-PCR from RNA directly extracted from uncultured bronchoalveolar lavage cells [13].

References