Codon usage patterns inEscherichia coli, Bacillus subtilis, Saccharomyces cerevisiae, Schizosaccharomyces pombe, Drosophila melanogasterandHomo sapiens; a review of the considerable within-species diversity

Abstract
The genetic code is degenerate, but alternative synonymous codons are generally not used with equal frequency. Since the pioneering work of Grantham'a group (1, 2) it has been apparent that genes from one species often share similarities incodon frequency; under the “genome hypothesis” (1, 2) there is a species-specific pattern to codon usage.