Evaluation of Codon usage pattern and its relation with differentially expressed genes between two populations of purebred and crossbreed Sistani and Montbeliarde cows

The aim of the present study was to investigate the codon usage pattern and their relationship with gene expression for genes with different expression between pure and crossbreed Sistani and Montbeliared breed. In this study, the results of differential gene expression analysis using RNA-Seq technology between pure and crossbreed Sistani and Montbeliared breed (two pure and two its crossbreed) were used. For this purpose, after determining the ORF regions for these genes, CodonW software was used to estimate codon usage pattern indices including CAI, ENC, GC and GC3s. Results showed that there was a significant correlation between total GC and GC3s (0.74). There was also a significant correlation between ENC and GC and GC3s (0.65, 0.77), indicating the role of mutation in codon formation. Based on the results of this study, the factors such as nucleotide composition (GC content), mutation, and gene expression level played important roles in codon formation in the genes studied in this study. This study is the first comparison between pure and crossbreed Sistani and Monti-billiard samples, which helps to better understand the evolutionary mechanisms of codon usage pattern formation and its association with gene expression.