Synonymous codon usage pattern in glycoprotein gene of rabies virus

Area of Science:

• Virology
• Molecular Biology
• Genetics

Background:

• Rabies virus (RABV) causes a fatal zoonotic disease, prevalent in developing nations.
• The RABV glycoprotein (G) is crucial for neurovirulence and is a key antigenic determinant.
• Factors influencing nucleotide choice and codon usage in the RABV G gene remain unexplored.

Purpose of the Study:

• To analyze synonymous codon usage and effective number of codons (Nc) in the RABV G gene.
• To identify the primary drivers of codon usage bias in the RABV G gene.

Main Methods:

• Analysis of relative synonymous codon usage (RSCU) and effective number of codons (Nc).
• Examination of 132 glycoprotein G genes from RABV.
• Correlation analysis between base composition, codon usage, Nc, and GC3.

Main Results:

• Mutational pressure is identified as the dominant factor influencing codon usage in the RABV G gene.
• A slight correlation between codon usage and factors like aromaticity, aliphatic index, and hydropathy suggests a role for natural selection.
• The study reveals major trends in codon usage patterns within the RABV G gene.

Conclusions:

• Codon usage bias in the RABV G gene is predominantly driven by mutational pressure.
• Natural selection contributes to codon usage variations, albeit to a lesser extent than mutational pressure.