Similarities Inferred From the Studies of
Long Range Correlations Among Mitochondrial
DNA Sequences
SK Gupta SK, TC Ghosh
Indian Journal of Biochemistry & Biophysics,
34(3), 259-265 (June 1997).
Abstract
Existence of long range correlations within the DNA sequences of
living organism has immense importance in understanding the
language of DNA sequences. Recently it has been reported that long
range correlations occur in DNA sequences. Some investigators
claimed that these type of correlations occur only on intron containing
DNA sequences. Some observers, however, have the opinion that long
range correlations do not distinguish between the intron containing
DNA sequences and intronless DNA sequences. The biological origin
of long range correlations in the DNA sequences is not clearly known.
In this paper we have demonstrated that long range correlations also
occur on intronless mitochondrial DNA sequences, indicating that
these special type of correlations are not the unique features for intron
containing DNA sequences. We have also demonstrated that long
range correlations simply originate in the region around which there is
a large variation of pyrimidine and purine ratios. The similarities
among the mitochondrial DNA sequences can be inferred by
computing the fractal exponents in the region where there is a large
variation of pyrimidine and purine ratio, as well as in the region where
the ratio of pyrimidine and purine fluctuates in a nearly constant
manner. In other words the similarities among the mitochondrial
DNA sequences cannot be inferred by calculating the fractral
exponents for the whole sequence.
