Highlights • Codon analysis reveal natural selection and other undefined factors dominates the overall codon usage bias in SARS-CoV-2 rather than mutational pressure. • The host adaptation potential of SARS-CoV-2 is more in human as compared to dog. Severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) is recognized as one of the life-threatening viruses causing the most destructive pandemic in this century. The genesis of this virus is still unknown. To elucidate its molecular evolution and regulation of gene expression, the knowledge of codon usage is a pre-requisite. In this study, an attempt was made to document the genome-wide codon usage profile and the various factors influencing the codon usage patterns of SARS-CoV-2 in human and dog. The SARS-CoV-2 genome showed relative abundance of A and U nucleotides and relative synonymous codon usage analysis revealed that the preferred synonymous codons mostly end with A/U. The analysis of ENc-GC3s, Neutrality and Parity rule 2 plots indicated that natural selection and other undefined factors dominate the overall codon usage bias in SARS-CoV-2 whereas the impact of mutation pressure is comparatively minor. The codon adaptation index and relative codon deoptimization index of SARS-CoV-2 deciphered that human is more favoured host for adaptation compared to dog. These results enhance our understanding of the factors involved in evolution of the novel human SARS-CoV-2 and its adaptability in dog.
【저자키워드】 SARS-CoV-2, Corona virus, dog, selection pressure, Codon Bias, 【초록키워드】 Evolution, pandemic, Mutation, Gene Expression, knowledge, virus, SARS-CoV-2 genome, natural selection, codon usage, host adaptation, molecular, nucleotide, Analysis, acute respiratory syndrome, Factor, Regulation, life-threatening, codon, human SARS-CoV-2, parity, neutrality, codon adaptation index, Host, synonymous, ENhance, involved, indicated, 【제목키워드】 virus, codon usage, acute respiratory syndrome,