Fig. 4.

Novel isoforms of the Slc41a3 gene mRNA. Screenshots from the UCSC genome browser, displaying mRNA-Seq reads from control and CR muscle samples mapping to annotated and novel exons in the Slc41a3 gene locus. The reads aligned to the Slc41a3 locus are shown at top (control, blue; CR, red). Slc41a3 transcripts annotated in the mainstream transcript databases are shown in the lower portion of the figure. mRNA-Seq detected two novel isoforms (isoform-a and isoform-b, in green) and their associated novel splice junctions. The stacks of mRNA-Seq reads on the left identify the novel first exon in both CR and control muscle samples (isoform-a). The mainstream transcript databases are shown, with no coding sequences annotated in the new exon region. Arrows beneath the first 3 exons of the novel transcript denote the positions of forward and reverse PCR primers used for validation in Fig. 3D. In addition control muscle contains a novel splice variant that lacks exon 2 (isoform-b).