Comprehensive analysis of codon usage pattern in Eisenia fetida and its correlation with gene expression

Every individual gene or genome follows the phenomenon of codon bias, where the usage among synonymous codons is not equal. The present study was conducted to understand the CUB in E. fetida and its impact on gene expression. The genes of E. fetida were G/Cbiased, where mean of C% was highest followed by G%, T%, and A% at the third codon position. ENC plot, Neutrality plot and Parity plot analysis revealed the codon usage pattern in E. fetida was largely influenced by natural selection. Further, it was observed that CUB had a substantial negative relationship with the gene expression levels (FPKM) at p < 0.05. Altogether, these findings indicate that translational efficiency and accuracy might have modulated the choice of codon selection in the studied earthworm genome.