Adaptation in the overall codon usage pattern of West Nile virus (WNV) to that of two hosts was estimated based on the synonymous codon usage value (RSCU). Synonymous codon usage biases for the beginning coding sequence of this virus were also analyzed by calculating the usage fluctuation for each synonymous codon along the target region (the first 270 codon sites of the whole coding sequence of WNV). Adaptation of WNV to Anopheles gambiae regarding the overall codon usage revealed a mixture of synonymous codon usage patterns between this virus and its vector.
Brachypodium distachyon has been proposed as a new model for the temperate grass because it is related to the major cereal grain species (such as wheat, barley, oat, maize, rice, and sorghum) and many forage and turf species. In this study, a multivariate statistical analysis was performed to investigate the characteristics of codon bias and the main factors affecting synonymous codon usage in Brachypodium. We found that low- and high-GC content genes with different codon usage occur frequently in the genome.