title: Strong sequence conservation among horizontally transmissible, minimally pathogenic feline leukemia viruses.
abstract: We report the first complete nucleotide sequence (8,440 base pairs) of a biologically active feline leukemia virus (FeLV), designated FeLV-61E (or F6A), and the molecular cloning, biological activity, and env-long terminal repeat (LTR) sequence of another FeLV isolate, FeLV-3281 (or F3A). F6A corresponds to the non-disease-specific common-form component of the immunodeficiency disease-inducing strain of FeLV, FeLV-FAIDS, and was isolated from tissue DNA of a cat following experimental transmission of naturally occurring feline acquired immunodeficiency syndrome. F3A clones were derived from a subgroup-A-virus-producing feline tumor cell line. Both are unusual relative to other molecularly cloned FeLVs studied to date in their ability to induce viremia in weanling (8-week-old) cats and in their failure to induce acute disease. The F6A provirus is organized into 5'-LTR-gag-pol-env-LTR-3' regions; the gag and pol open reading frames are separated by an amber codon, and env is in a different reading frame. The deduced extracellular glycoproteins of F6A, F3A, and the Glasgow-1 subgroup A isolate of FeLV (M. Stewart, M. Warnock, A. Wheeler, N. Wilkie, J. Mullins, D. Onions, and J. Neil, J. Virol. 58:825-834, 1986) are 98% homologous, despite having been isolated from naturally infected cats 6 to 13 years apart and from widely different geographic locations. As a group, their envelope gene sequences differ markedly from those of the disease-associated subgroup B and acutely pathogenic subgroup C viruses. Thus, F6A and F3A correspond to members of a highly conserved family and represent prototypes of the horizontally transmitted, minimally pathogenic FeLV present in all naturally occurring infections.
authors.affiliation: Department of Cancer Biology, Harvard School of Public Health, Boston, Massachusetts 02115.
authors.forename: P R
authors.initials: PR
authors.lastname: Donahue
authors.forename: E A
authors.initials: EA
authors.lastname: Hoover
authors.forename: G A
authors.initials: GA
authors.lastname: Beltz
authors.forename: N
authors.initials: N
authors.lastname: Riedel
authors.forename: V M
authors.initials: VM
authors.lastname: Hirsch
authors.forename: J
authors.initials: J
authors.lastname: Overbaugh
authors.forename: J I
authors.initials: JI
authors.lastname: Mullins
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002371:Cat Diseases / Q000382:microbiology / Q000635:transmission; D002415:Cats; D004279:DNA, Viral / Q000235:genetics; D005814:Genes, Viral; D007153:Immunologic Deficiency Syndromes / Q000382:microbiology / Q000662:veterinary; D007938:Leukemia / Q000382:microbiology / Q000635:transmission / Q000662:veterinary; D005256:Leukemia Virus, Feline / Q000145:classification / Q000235:genetics* / Q000472:pathogenicity; D008969:Molecular Sequence Data; D012191:Retroviridae Proteins / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D014759:Viral Envelope Proteins / Q000235:genetics
chemical_list: D004279:DNA, Viral; D012191:Retroviridae Proteins; D014759:Viral Envelope Proteins