Genome-scale compositional comparisons in eukaryotes

We examined dinucleotide relative abundances and their biases in recent seq uences of eukaryotic genomes and chromosomes, including human chromosomes 2 1 and 22, Saccharomyces cerevisiae, Arabidopsis thaliana, and Drosophila me lanogaster. We found that dinucleotide relative abundances are remarkably c onstant across human chromosomes and within the DNA of a particular species . The dinucleotide biases differ between species, providing a genome signat ure that is characteristic of the bulk properties of an organism's DNA. We detail the relations between species genome signatures and suggest possible mechanisms for their origin and maintenance.