Detecting salient changes in genomic signals

The functional state of an organism is determined largely by the pattern of the expression of its genes. Salient changes in variation in expression of genes can give clues about important events, such as the onset of a disease. We address the problem of detecting salient inflection points in genomic signals. These are detected using a scale-space decomposition, to be the negative-going zero-crossings of the second derivative of smoothed signals that are preserved over an automatically selected scale. The utility of salient change detection is demonstrated in the automatic identification of the regulatory phase for genes active in the mitotic cell cycle of budding yeast.