Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 7-Day Trial for You or Your Team.

Learn More →

Relative roles of primary sequence and (G + C)% in determining the hierarchy of frequencies of complementary trinucleotide pairs in DNAs of different species

Relative roles of primary sequence and (G + C)% in determining the hierarchy of frequencies of... To an approximation Chargaff's rule (%A = %T; %G = %C) applies to single-stranded DNA. In long sequences, not only complementary bases but also complementary oligonucleotides are present in approximately equal frequencies. This applies to all species studied. However, species usually differ in base composition. With the goal of understanding the evolutionary forces involved, I have compared the frequencies of trinucleotides in long sequences and their shuffled counterparts. Among the 32 complementary trinucleotide pairs there is a hierarchy of frequencies which is influenced both by base composition (not affected by shuffling the order of the bases) and by base order (affected by shuffling). The influence of base order is greatest in DNA of 50% G + C and seems to reflects a more fundamental hierarchy of dinucleotide frequencies. Thus if TpA is at low frequency, all eight TpA-containing trinucleotides are at low frequency. Mammals and their viruses share similar hierarchies, with intra- and intergenomic differences being mainly associated with differences in base composition (percentage G + C). E. coli and, to a lesser extent, Drosophila melanogaster hierarchies differ from mammalian hierarchies; this is associated with differences both in base composition and in base order. It is proposed that Chargaff's rule applies to single-stranded DNA because there has been an evolutionary selection pressure favoring mutations that generate complementary oligonucleotides in close proximity, thus creating a potential to form stem-loops. These are dispersed throughout genomes and are rate-limiting in recombination. Differences in (G + C)% between species would impair interspecies recombination by interfering with stem-loop interactions. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Journal of Molecular Evolution Springer Journals

Relative roles of primary sequence and (G + C)% in determining the hierarchy of frequencies of complementary trinucleotide pairs in DNAs of different species

Forsdyke, D. R.
Journal of Molecular Evolution , Volume 41 (5) – Nov 1, 1995
Download PDF
9 pages

Loading next page...
 
/lp/springer-journals/relative-roles-of-primary-sequence-and-g-c-in-determining-the-Ck06mTYL90

References (27)

Publisher
Springer Journals
Copyright
Copyright © Springer-Verlag New York Inc 1995
ISSN
0022-2844
eISSN
1432-1432
DOI
10.1007/bf00175815
Publisher site
See Article on Publisher Site

Abstract

To an approximation Chargaff's rule (%A = %T; %G = %C) applies to single-stranded DNA. In long sequences, not only complementary bases but also complementary oligonucleotides are present in approximately equal frequencies. This applies to all species studied. However, species usually differ in base composition. With the goal of understanding the evolutionary forces involved, I have compared the frequencies of trinucleotides in long sequences and their shuffled counterparts. Among the 32 complementary trinucleotide pairs there is a hierarchy of frequencies which is influenced both by base composition (not affected by shuffling the order of the bases) and by base order (affected by shuffling). The influence of base order is greatest in DNA of 50% G + C and seems to reflects a more fundamental hierarchy of dinucleotide frequencies. Thus if TpA is at low frequency, all eight TpA-containing trinucleotides are at low frequency. Mammals and their viruses share similar hierarchies, with intra- and intergenomic differences being mainly associated with differences in base composition (percentage G + C). E. coli and, to a lesser extent, Drosophila melanogaster hierarchies differ from mammalian hierarchies; this is associated with differences both in base composition and in base order. It is proposed that Chargaff's rule applies to single-stranded DNA because there has been an evolutionary selection pressure favoring mutations that generate complementary oligonucleotides in close proximity, thus creating a potential to form stem-loops. These are dispersed throughout genomes and are rate-limiting in recombination. Differences in (G + C)% between species would impair interspecies recombination by interfering with stem-loop interactions.

Journal

Journal of Molecular Evolution – Springer Journals

Published: Nov 1, 1995

Keywords: Chargaff's rule; Stem-loop; Recombination; Speciation

There are no references for this article.