Correlation Analyses of Codons and Corresponding Complementary Codons Usage
To reveal the relationship between codons and corresponding complementary codons usage, the data of codon and corresponding complementary codon usage from 44 cellular organisms, 16 viruses, 40 mitochondria and 20 chloroplasts were analyzed. Significant correlations between codons and corresponding complementary codons usage were found in the majority of the studied subjects except viruses, albeit there was also significant heterogeneity among them. The degree of correlation between codons and corresponding complementary codons usage may be used as an index not only for measuring the degree of selection force during organism evolution, but also for exploring the degree of anticodons' modification and wobbling-pairing with corresponding codons within organisms. In addition, it is also discussed that the two strands of DNA may have simultaneous coding function in the early stage of organism evolution.