iPiG: Integrating Peptide Spectrum Matches into Genome Browser Visualizations
Custom annotation tracks showing mapped peptides from an iPiG BED file imported into the UCSC Genome Browser. The peptide tracks only contain unique peptides that are mapped to referenced genes (annotation-filtered mapping). The peptides can be easily shown in context with other annotations such as the UCSC Genes (blue track). In particular, here PSMs are shown that mapped to the region of the gene CELA2A on chromosome one. The first PSM track (squish) shows all PSMs individually, where the different colors (grey, orange, green) code for different identification scores (low, mid, high). The second PSM track (dense) shows the PSMs overlapping and thus indicating a contiguous object. Both PSM tracks accurately represent the exon-intron structure of the corresponding gene, where thick blocks indicate exon parts and thin lines and arrows indicate intron parts resp. strand orientation.