Dual reporter assay of CD45 splicing identified clones with “activated” splicing phenotype. (A) Scheme of dual-reporter system. (B) Flow cytometry analysis of GFP expression in mock-infected resting 3.14 cells (filled), initial cDNA infected cell population (line, left), or resting cell population after recovery from the initial sort (line, right). Circle on left indicates cells that were gated and collected in the initial sort. (C) Graphic representation of exon 4 inclusion in reporter minigene in 106 GFP+ clones (▲), compared with resting (●) or stimulated (■) 3.14 cells. Exon 4 inclusion in all cases was quantitated by low-cycle RT–PCR. Triangles corresponding to data from the three clones chosen for further study are indicated.
