Codon distributions in DNA.

The codons, 64 in number, are distributed over the coding parts of DNA sequences. The distribution function is the plot of frequency versus rank of the codons. These distributions are characterized by parameters that are almost universal, i.e., gene independent. There is but a small part that depends on the gene. We present the theory to calculate the universal (gene-independent) part. The part that is gene-specific, however, has undetermined overlaps and fluctuations.