Abstract
We use the wavelet transform modulus maxima method to investigate the multifractal properties of strand-asymmetry DNA walk profiles in the human genome. This study reveals the bifractal nature of these profiles, which involve two competing scale-invariant (up to repeat-masked distances ) components characterized by Hölder exponents and , respectively. The former corresponds to the long-range-correlated homogeneous fluctuations previously observed in DNA walks generated with structural codings. The latter is associated with the presence of jumps in the original strand-asymmetry noisy signal . We show that a majority of upward (downward) jumps colocate with gene transcription start (end) sites. Here 7228 human gene transcription start sites from the refGene database are found within from an upward jump of amplitude which suggests that about 36% of annotated human genes present significant transcription-induced strand asymmetry and very likely high expression rate.
- Received 8 July 2006
DOI:https://doi.org/10.1103/PhysRevE.75.032902
©2007 American Physical Society