RNA expression of KIF23. (A) Schematic representation of alternative splicing of the exons 17 and 18 of KIF23. The primers used for RT-PCR are indicated by arrows. Two previously reported transcripts (FL and Δ18) as well as a novel one (Δ17+18) are illustrated with the expected sizes of the RT-PCR products. (B) Detection of KIF23 transcripts and a control glyceraldehyde-3-phosphate dehydrogenase (GAPDH) transcript in a broad range of tissues by RT-PCR with primers 16F and 19R (top), 17F and 18R (middle), and GAPDH primers (bottom). Under these conditions, the primers 16F and 19R detected the Δ18 and Δ17+18 transcripts but not the FL transcript, although its expression was observed with the primers 17F and 18R (FL). MassRuler Low Range DNA Ladder (80-1031 bp) and pUC19DNA/MspI (HpaII) Marker, 23 (Thermo Fisher Scientific, Inc., Waltham, MA) were used as a size standard for KIF23 and GAPDH, respectively.