       Document 0107
 DOCN  M9460107
 TI    Evolution of feline leukemia virus variant genomes with insertions,
       deletions, and defective envelope genes in infected cats with tumors.
 DT    9404
 AU    Rohn JL; Linenberger ML; Hoover EA; Overbaugh J; Department of
       Microbiology, University of Washington, Seattle; 98195.
 SO    J Virol. 1994 Apr;68(4):2458-67. Unique Identifier : AIDSLINE
       GENBANK/U03227
 AB    In order to study retroviral variation, selection, and viral correlates
       of in vivo pathogenicity, we documented the evolution of feline leukemia
       virus (FeLV) variants in cats that died with thymic lymphoma after
       infection with molecularly cloned subgroup A FeLV. Using genomic DNA
       from cat necropsy samples, we employed PCR to amplify and clone the
       envelope gene, which is a major determinant of the specific
       pathogenicity of different FeLV variants. In the envelope gene,
       mutations encoded scattered amino acid changes that did not cluster into
       clearly definable variable regions; however, characterization of these
       terminal variant sequences revealed a predominance of G-to-A and A-to-G
       nucleotide substitutions. Additionally, some cats harbored variants with
       recombinant subgroup B-like envelope genes, while the major variant from
       one cat had a 12-bp insertion in a region previously characterized as an
       immunodeficiency-inducing determinant. Finally, proviruses from tumor
       DNA frequently possessed envelope genes predicted to encode a protein
       truncated in the N-terminal half because of either premature termination
       codons or deletions ranging from 29 to 1,666 bp. In contrast, all
       envelope genes cloned from the bone marrow of one cat were predicted to
       encode full-length envelope product, and only a minority of proviral
       clones from a cat that did not develop a tumor had defective envelope
       genes. Thus, in the cat, viruses evolved from subgroup A FeLV that had
       point mutations, insertions, deletions, or recombinant envelope genes.
       Furthermore, defective variants were particularly prominent in T-cell
       tumors.
 DE    Amino Acid Sequence  Animal  Base Sequence  Cats  Cloning, Molecular
       Comparative Study  Genes, env/*GENETICS  Genome, Viral  Leukemia Virus,
       Feline/*GENETICS  Lymphoma/*MICROBIOLOGY  Molecular Sequence Data
       Mutagenesis  Proviruses/GENETICS  Retroviridae Infections/*MICROBIOLOGY
       Sequence Analysis, DNA  Sequence Deletion  Sequence Homology, Amino Acid
       Support, U.S. Gov't, P.H.S.  Thymus Neoplasms/*MICROBIOLOGY  Tumor Virus
       Infections/*MICROBIOLOGY  Variation (Genetics)  JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).

