SFP discovery and validation at the Unigene level. Examples for genes MU16815 and MU17949 are shown. The graph shows that the signal ratio of the putative SFP is stronger than all other probe sets of the same gene. The signal ratio (y axis) is plotted against the probe position relative to the 5' end of the UniGene contig (x axis). The red dots represent the probes that are predicted to contain SFPs based on statistical analysis. The signal ratio consists of 'Dulce' signal to PI414723 signal, and therefore a positive log signal ratio represents a PI414723 SFP, i.e., 'Dulce' better matches the probe. A negative log signal ratio represents a 'Dulce' SFP. The variation in 'Dulce' and PI414723 SFPs (corresponding to the red dots in the top part of the figure) is revealed by sequencing, illustrated in the bottom part of the graph.