3' acceptor site selection depends on the AG-to-AG and BPS-to-AG distances. NM_014226-E6-I6-E7 (RAGE) (A) and NM_015179-E32-I32-E33 (RRP12) (B) minigene vectors containing four different distances between the proximal and distal AG, CAG(C)1AG, CAG(C)2AG; CAG(C)3AG and CAG(C)4AG (construction as shown in a panels). These minigenes were transfected into a HeLa cell line, and after 48 h total RNA and alternative splicing patterns were assayed as mentioned in the Materials and Methods. The expression profiles of these minigenes are indicated in the b panels and the relative percentage of the two isoforms was showed in the c panels. (C) and (D) The BPS-to-AG distance of NM_015179-E32-I32-E33 was extended by inserting cytosines into the PPT region. These constructs are shown in the a panels and their expression profiles are indicated in the b panels and the relative percentage of the two isoforms was showed in the c panels. The arrowheads and arrows indicate the use of distal and proximal AG, respectively. The percentage of wobble splicing isoforms is shown at the top of each b panel and the relative use of each AG is indicated by the thickness of the underlining in each a panel.