Nucleotide sequence of the splice junction of feline leukemia virus envelope mRNA.

The splice donor and acceptor sequences for the subgenomic envelope messenger RNA of feline leukemia virus (FeLV) were determined. The splice junction was characterized for viral mRNA from a prototype subgroup A FelV and an immunodeficiency-inducing FeLV variant. Thirty-seven of 38 partial envelope cDNAs, cloned after PCR amplification from T cells infected with either virus, utilized the same splice donor and acceptor sites to generate a mRNA that would be predicted to encode envelope protein. One novel cDNA, which could also code for envelope protein, was generated from a cryptic splice acceptor 109 nucleotides downstream of the normal junction. No additional subgenomic FeLV gene products were detected using reverse transcription and polymerase chain reaction amplification of FeLV sequences from chronically infected cells.