Gaining Insights into the Codon Usage Patterns of TP53 Gene across Eight Mammalian Species

Mazumder, Tarikul Huda; Chakraborty, Supriyo

In brief, our results showed that codon usage in TP53 gene in mammals has been influenced by GC bias, mainly due to GC 3s . The majority of frequently used codons were G/C ending in which C-ending codons were mostly favored compared to G-ending codons for the corresponding amino acid. The most over-represented codon was CTG encoding the amino acid leucine in the TP53 gene of all the selected mammalian species. We further observed that the codon ATA encoding isoleucine was selected against by nature in TP53 genes across the mammalian species under study during the course of evolution. The codon usage pattern for TP53 in H. sapiens showed resemblance to that of M. mulatta; similarly, F. catus to C. lupus and M. unguiculatus to R. norvigicus. Moderate codon bias was observed for the TP53 gene in different mammalian species. The codon usage patterns in the coding sequence of TP53 gene across different mammalian species showed significant similarities, suggesting that the evolutionary pattern might be similar. According to Yang and Nielsen (2008) , codon bias in mammals is mainly influenced by mutation bias and the selection on codon bias is weak for nearly neutral synonymous mutations [40] . From the outstanding work of Grantham et al., (1980 Grantham et al., ( -1981 on "genome hypothesis" it was evident that species specific genes share similar spectrum of codon usage frequency [41, 42] . The present study revealed that specific gene of closely related species with similar functions exhibit similar patterns of codon bias across different mammals as evident from the previous work of Dass et al., (2012) [35] . To the best of our knowledge, this is the first report on the codon usage pattern in TP53 gene across the mammalian species. Since our analysis has given better insights into the codon usage, it may have theoretical value in further understanding the molecular evolution of TP53gene.