Alternative splicing of the Hinge I region. (A) Schematic representation of the genomic structure encoding the Hinge I region and the PCR products amplified with specific primers P3, P4, P5, and P6. The genomic sequences encoding the Hinge I region and partial sequences of adjacent repeats 15 and 16 are boxed. Intron sequences are represented by dashed lines. The PCR primers specific for ABP-278 (P3, P4, P5, and P6) are labeled. The position of exon-intron junctions are indicated by vertical arrows and numbered. (B) Diagram of the formation of ABP-278 and its isoform ABP-276 by alternative RNA splicing. (C) Partial sequences of exon-intron junctions as numbered in (A). Splice juntions are indicated by slash. The consensus donor (gt) and acceptor (ag) dinucleotides are underlined.