Gene Identification Using the Z-Curve Representation

DSP based techniques have been recently proposed to identify the protein coding regions in a DNA strand by detecting the so-called period-3 component in the DNA spectrum. The DNA spectrum is computed after mapping the DNA symbolic sequence to numerical digital sequences. A typical choice of mapping is the Voss representation. In this paper, we propose the use of a more elaborate mapping scheme, namely the Z-curve representation. Using a multirate signal processing approach, we derive closed form expressions to compute the Z-curve based DNA spectrum as well as mathematical conditions that characterize the coding regions. The derived formulas also prove that the Z-curve representation yields essentially the same DNA spectrum as the one obtained using the Voss representation at a lower computational cost