Codon Usage and Transfer RNA Contents: Organism-specific Codon-choice Patterns in Reference to the Isoacceptor Contents

The choice of synonymous codons in both prokaryotic and eukaryotic genes is strongly biased. There exist clear similarities in codon usage among different genes of the same or taxonomically related organisms, regardless of the functions of the genes or the dissimilarities among the genes (even among those encoding cognate proteins) of taxonomically distant organisms (Grantham et al. 1980, 1981; Ikemura 1981a,b, 1982).