Figure 3.

Structures of aberrant chimeric mRNAs. (a) Schematic representation of the aberrantly spliced mRNA and the expression unit in the E3 region. The LacZ expression units in the E3 region are shown. Aberrant mRNAs are shown in red. The bold lines and thin polygonal lines represent the exon and intron of the transcript, respectively. Arrow, orientation of the transcription; EF, EF1α promoter; LacZ, LacZ DNA. The ‘parent' denotes the vectors before the insertion into the E3. ‘LacZ-fiber,' ‘MLP-EF,' ‘LacZ-E2A' and ‘E4-EF' indicate combinations of primers for detection of the chimeric mRNAs. (b) Detection of aberrant splicing by PCR. The 293 cells were infected with the Z-E3L and Z-E3R vectors, as indicated. The bands are generated from the chimera-specific mRNA between the viral gene and the inserted transgene. The primer sequences are shown in Supplementary Table S2. M, size maker; -, no DNA. (c) Specificity of the aberrant splicing. The 293 cells were infected with either Z-E3L or Z-E3R. The splicing from the MLP to hexon was used as the control. The bands of LacZ-fiber and MLP-EF in Z-E3R are the same as those described in (b) (0.7 and 1.2 kb, respectively). These bands were not detected in Z-E3L (lanes 3 and 1); threefold more DNA was loaded in lane 3 than in lane 1 to clearly show the semi-quantitative difference in the amount of cDNA. mock, mock infection of the 293 cells.