Analysis of hnRNP A2/B1-neo fusion transcripts. (A) Strategy used to amplify fusion transcripts. The provirus is shown downstream of a 5' splice site (5'SS) in the hnRNP A2/B1 gene. The positions of the primers used for reverse transcriptase PCR (RT-PCR) are indicated. (B) Gel analysis of RT-PCR products of. PCR reactions were performed before (-RT) or after (+RT) first strand cDNAsynthesis with the neoA primer. PCR reactions using DNA templates were performed to provide controls for products amplified from unspliced transcripts. PCR products were fractionated on a 1% agarose gel and stained with ethidium bromide. Sizes of the RT-PCR products are indicated. (C) PCR products from B were analyzed by Southern blot using a U3 oligo as a probe. Arrows indicate the mobility of RT-PCR products seen in C. (D) Sequence alignment of RT-PCR products with genomic sequences. 5' splice site (5'), 3' splice site (3'), and branch point (BP) consensus sequences are shown for comparison.