HTLV-2 antisense transcription initiates in the 3′-LTR. (A) The 5′RACE PCR analysis was conducted using RNA samples from 293T cells transfected with pHTLV-2 ΔEcoRI (lane 2). The cDNA was synthesized with a modified oligo dT and ligated to a supplied anchor at their 5′ end. Two subsequent PCR rounds were conducted with the 5′RACE outer and inner primers along with the transcript-specific 24-2 and 21-2 reverse primers As a negative control (lane 1), final PCR amplification was performed with water (ie, no cDNA). The resulting amplified products were run on an agarose gel. M indicates 100-bp marker. (B) The position of the identified transcription initiation sites of APH-2 mRNA (◣ represents 293T; , Mo) is depicted in the 3′-LTR. Nucleotide positioning is relative to the APH-2 ATG initiation codon numbered as +1. The numbering in the proviral DNA corresponds to the sense strand.