Figure 1

Identification of alternative Tmem16a exons 6b, 13 and 15 in mouse heart. A. Expression of Tmem16 family members were analyzed in mouse heart using RT-PCR primers specific for each of the ten Tmem16 paralogs. Amplification products were resolved on 2% agarose gels alongside a 100 bp marker. Fragments of the expected molecular size indicated the expression of Tmem16a, c, d, e, f, h, j and k paralogs in mouse heart. Tmem16b and g were not detected. B. Schematic representations of regions of Tmem16a RNA. Boxed numbers indicate exons relative to the Tmem16a gene. Alternative exon 6b (66 bp), exon 13 (12 bp) and exon 15 (78 bp) in the mouse Tmem16a coding sequence are highlighted. RT-PCR primers (± exon 6b, ± exon 13, ± exon 15), which amplify across each alternative exon are indicated. RT-PCR gel analysis of exon 6b, 13 and 15 Tmem16a variants expressed in mouse heart. Primers ± exon 6b amplify a 367 and/or a 433 bp product, primers ± exon 13 amplify a 165 and/or a 177 bp product, primers ± exon 15 amplify a 297 and/or a 375 bp product. The upper bands correspond to Tmem16a variants that include the alternative exon and differ in size corresponding to the size of that exon. C. RT-PCR primer sets that span exon boundaries to selectively amplify individual alternative exons are indicated. Gel analysis of Tmem16a fragments expressed in mouse heart that either include or exclude exons 6b, 13 or 15. Each primer set yielded a single band of the expected size. RT-PCR products were sequenced for confirmation.