Bifractality of human DNA strand-asymmetry profiles results from transcription.
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 less, or similar 40 kbp) components characterized by Hölder exponents h{1}=0.78 and h{2}=1, 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 S. We show that a majority of upward (downward) jumps co-locate with gene transcription start (end) sites. Here 7228 human gene transcription start sites from the refGene database are found within 2 kbp from an upward jump of amplitude DeltaS > or = 0.1 which suggests that about 36% of annotated human genes present significant transcription-induced strand asymmetry and very likely high expression rate.
Nicolay
S
S
Laboratoire Joliot-Curie and Laboratoire de Physique, UMR 5672, CNRS, ENS-Lyon, 46 Allée d'Italie, 69364 Lyon Cedex 07, France.
Brodie Of Brodie
E B
EB
Touchon
M
M
Audit
B
B
d'Aubenton-Carafa
Y
Y
Thermes
C
C
Arneodo
A
A
D001483:Base Sequence; D002874:Chromosome Mapping / Q000379:methods*; D004247:DNA / Q000737:chemistry* / Q000235:genetics*; D017709:Fractals; D006801:Humans; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA / Q000379:methods*; D014158:Transcription, Genetic / Q000235:genetics*
D004247:DNA