A study on codon usage bias in cytochrome c oxidase I (COI) gene of solitary ascidian Herdmania momus Savigny, 1816

Synonymous codon usage bias is an inevitable phenomenon in organismic taxa, where synonymous codons occur at uneven frequencies in gene. Synonymous codon usage pattern differs between species and also among the genes of a genome. Codon usage bias is determined under various degrees by mutational bias, natural selection and other factors. In this study codon usage pattern of cytochrome coxidase I (COI) gene of a solitary ascidian Herdmania momus was determined by analyzing the nucleotide content, codon distribution frequency, hydrophobicity, Relative Synonymous Codon Usage (RSCU), Effective Number of Codons (ENC), GC3and Codon Adaptation Index (CAI) values. Results presented low GC content and higher ENC values indicating less bias in codon usage preference. The Grand Average of Hydropathicity (GRAVY) values and hydropathy plot confirmed the hydrophobic nature of COI the protein.