Figure 6

Detection of isoform-specific peptides plays a critical role in identifying alternatively spliced isoforms. The finding of two putative isoforms of A. flavus UDP-galactose 4 epimerase is illustrated as an example. Isoform A (RefSeq protein) and Isoform B (putative splice isoform) were identified by shared (green) and unique (yellow/blue) peptides. The identifications of both Isoform A and B are needed to declare the occurrence of an alternative splicing event. The detection of the splice isoform-specific (blue) peptide is decisive for the identification of Isoform B. Since only one isoform-specific peptide was found in this example, a false positive or missed identification of the peptide could alter the result of the isoform detection.