https://www.selleckchem.com/products/diphenhydramine.html 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.Silkworms have been used as a host for the production of recombinant proteins in a baculovirus expression system using Bombyx mori nucleopolyhedrovirus (BmNPV). To coexpress several recombinant proteins, a silkworm must be coinfected with several recombinant BmNPVs, which requires a difficult DNA manipulation procedure. In this study, we constructed recombinant BmNPVs containing three expression cassettes, Rous sarcoma virus (RSV) Gag protein, surface antigen 1 of Neospora caninum (NcSAG1) and SAG1-related sequence 2 of N. caninum (NcSRS2), by Gibson assembly and the Bac-to-Bac system, designated BmNPV/SAG-SRS-Gag and BmNPV/SAG-Gag-SRS. BmNPV/SAG-SRS-Gag was expressed in silkworms and characterized. NcSAG1 an