Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 1993
Jun;47(6):4514-23.
Generalized Levy-walk model for DNA nucleotide sequences.
Buldyrev SV, Goldberger AL, Havlin S, Peng C-K, Simons M, Stanley HE.
Center for Polymer Studies and Department of Physics, Boston University,
Massachusetts 02215.
We propose a generalized Levy walk to model fractal landscapes observed in
noncoding DNA sequences. We find that this model provides a very close
approximation to the empirical data and explains a number of statistical
properties of genomic DNA sequences such as the distribution of strand-biased
regions (those with an excess of one type of nucleotide) as well as local
changes in the slope of the correlation exponent alpha. The generalized
Levy-walk model simultaneously accounts for the long-range correlations in
noncoding DNA sequences and for the apparently paradoxical finding of long
subregions of biased random walks (length lj) within these correlated sequences.
In the generalized Levy-walk model, the lj are chosen from a power-law
distribution P(lj) varies as lj(-mu). The correlation exponent alpha is related
to mu through alpha = 2-mu/2 if 2 < mu < 3. The model is consistent with the
finding of "repetitive elements" of variable length interspersed within
noncoding DNA.
PMID: 9960527 [PubMed - indexed for MEDLINE]