Fig 2.

Foamy virus reverse transcriptase template switch is dependent on Gag processing. (A) Schema of the first steps of the reverse transcription and the position of the PCR products (DNA, black; RNA, gray). (B) Amplification of the RU5 region from viral cDNAs with primers located in R and U5. wt, wild type. (C) PCR with U3-specific primers using concentrated recombinant viruses as the template. The recombinant viruses were analyzed by Western blotting using a monoclonal Gag-specific antibody. The Gag signals of the different mutants were quantified using the AIDA software package (GE Healthcare) and normalized on Gag content, to guarantee equal Gag amounts in the PCRs. Identical amounts of concentrated viruses were used for RU5 and U3 PCR.