ANALYSIS OF APPARENT 1 F-ALPHA SPECTRUM IN DNA-SEQUENCES/

The question whether the correlations in DNA sequences are long ranged or short ranged is addressed by an extensive analysis of genetic sequ ences. Our results do not support the notion of critical properties of sequential distribution of nucleotides. Continuous segments of DNA (c hromosomes) can be viewed as a mosaic structure of shorter segments wi th distinct functional role and, consequently, with distinct compositi onal and sequential characteristics. It is shown that the correlation functions within well-defined sequential entities decay exponentially after one or two hundred nucleotides. The main contribution to the cor relations stems from the correlated distributions of repetitions of si milar nucleotides. If the analysis of correlations is performed withou t respect to the borders between functional entities one obtains the s igns of long-range correlations.