scholarly journals Codon Usage Bias in Autophagy-Related Gene 13 in Eukaryotes: Uncovering the Genetic Divergence by the Interplay Between Nucleotides and Codon Usages

Author(s):  
Yicong Li ◽  
Rui Wang ◽  
Huihui Wang ◽  
Feiyang Pu ◽  
Xili Feng ◽  
...  

Synonymous codon usage bias is a universal characteristic of genomes across various organisms. Autophagy-related gene 13 (atg13) is one essential gene for autophagy initiation, yet the evolutionary trends of the atg13 gene at the usages of nucleotide and synonymous codon remains unexplored. According to phylogenetic analyses for the atg13 gene of 226 eukaryotic organisms at the nucleotide and amino acid levels, it is clear that their nucleotide usages exhibit more genetic information than their amino acid usages. Specifically, the overall nucleotide usage bias quantified by information entropy reflected that the usage biases at the first and second codon positions were stronger than those at the third position of the atg13 genes. Furthermore, the bias level of nucleotide ‘G’ usage is highest, while that of nucleotide ‘C’ usage is lowest in the atg13 genes. On top of that, genetic features represented by synonymous codon usage exhibits a species-specific pattern on the evolution of the atg13 genes to some extent. Interestingly, the codon usages of atg13 genes in the ancestor animals (Latimeria chalumnae, Petromyzon marinus, and Rhinatrema bivittatum) are strongly influenced by mutation pressure from nucleotide composition constraint. However, the distributions of nucleotide composition at different codon positions in the atg13 gene display that natural selection still dominates atg13 codon usages during organisms’ evolution.

Viruses ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1087 ◽  
Author(s):  
Sheng-Lin Shi ◽  
Run-Xi Xia

All iflavirus members belong to the unique genus, Iflavirus, of the family, Iflaviridae. The host taxa and sequence identities of these viruses are diverse. A codon usage bias, maintained by a balance between selection, mutation, and genetic drift, exists in a wide variety of organisms. We characterized the codon usage patterns of 44 iflavirus genomes that were isolated from the classes, Insecta, Arachnida, Mammalia, and Malacostraca. Iflaviruses lack a strong codon usage bias when they are evaluated using an effective number of codons. The odds ratios of the majority of dinucleotides are within the normal range. However, the dinucleotides at the 1st–2nd codon positions are more biased than those at the 2nd–3rd codon positions. Plots of effective numbers of codons, relative neutrality analysis, and PR2 bias analysis all indicate that selection pressure dominates mutations in shaping codon usage patterns in the family, Iflaviridae. When these viruses were grouped into their host taxa, we found that the indices, including the nucleotide composition, effective number of codons, relative synonymous codon usage, and the influencing factors behind the codon usage patterns, all show that there are non-significant differences between the six host-taxa-groups. Our results disagree with our assumption that diverse viruses should possess diverse codon usage patterns, suggesting that the nucleotide composition and codon usage in the family, Iflaviridae, are not host taxa-specific signatures.


2021 ◽  
Author(s):  
Puttatida Mahapattanakul ◽  
Pragun Rajbhandari ◽  
Patsarin Rodpothong

Abstract Codon usage is a reflection of evolutionary adaptation to environmental pressure. The pattern of usage may be unique to species of viruses, genomes of the same species or genes within the same genome. Here we have analysed the overall nucleotide composition and the nucleotides at different codon positions in the genomes of 6 Alphabaculoviruses. Principle Component Analysis (PCA) based on Relative Synonymous Codon Usage (RSCU) of all Open Reading Frames (ORFs) was employed to investigate the pattern of the codon usage. The results suggest the Alphabaculovirus genomes, except that of Agrotis Ipsilon mNPV (AgipNPV), are predominantly under an influence of a neutral mutation that bias toward A/T. The majority of the ORFs, except those of the AgipNPV, cluster at the same location in the 2-dimensional PCA map with one prominent outlier that has been identified as a P6.9 gene. The six Alpha-baculovirus P6.9 genes have a high G/C content, dissimilar to the majority of the ORFs. The G/C content is found to be significantly high at the 2 nd codon position, suggesting the influence of natural selection and perhaps reflecting its functional conservation in DNA packaging as well as its evolutionary relation to Protamine.


Genetics ◽  
2001 ◽  
Vol 159 (3) ◽  
pp. 1191-1199
Author(s):  
Araxi O Urrutia ◽  
Laurence D Hurst

Abstract In numerous species, from bacteria to Drosophila, evidence suggests that selection acts even on synonymous codon usage: codon bias is greater in more abundantly expressed genes, the rate of synonymous evolution is lower in genes with greater codon bias, and there is consistency between genes in the same species in which codons are preferred. In contrast, in mammals, while nonequal use of alternative codons is observed, the bias is attributed to the background variance in nucleotide concentrations, reflected in the similar nucleotide composition of flanking noncoding and exonic third sites. However, a systematic examination of the covariants of codon usage controlling for background nucleotide content has yet to be performed. Here we present a new method to measure codon bias that corrects for background nucleotide content and apply this to 2396 human genes. Nearly all (99%) exhibit a higher amount of codon bias than expected by chance. The patterns associated with selectively driven codon bias are weakly recovered: Broadly expressed genes have a higher level of bias than do tissue-specific genes, the bias is higher for genes with lower rates of synonymous substitutions, and certain codons are repeatedly preferred. However, while these patterns are suggestive, the first two patterns appear to be methodological artifacts. The last pattern reflects in part biases in usage of nucleotide pairs. We conclude that we find no evidence for selection on codon usage in humans.


2011 ◽  
Vol 57 (12) ◽  
pp. 1016-1023 ◽  
Author(s):  
Xue Lian Luo ◽  
Jian Guo Xu ◽  
Chang Yun Ye

In this study, we analysed synonymous codon usage in Shigella flexneri 2a strain 301 (Sf301) and performed a comparative analysis of synonymous codon usage patterns in Sf301 and other strains of Shigella and Escherichia coli . Although there was a significant variety in codon usage bias among different Sf301 genes, there was a slight but observable codon usage bias that could primarily be attributable to mutational pressure and translational selection. In addition, the relative abundance of dinucleotides in Sf301 was observed to be independent of the overall base composition but was still caused by differential mutational pressure; this also shaped codon usage. By comparing the relative synonymous codon usage values across different Shigella and E. coli strains, we suggested that the synonymous codon usage pattern in the Shigella genomes was strain specific. This study represents a comprehensive analysis of Shigella codon usage patterns and provides a basic understanding of the mechanisms underlying codon usage bias.


2014 ◽  
Vol 13 (3) ◽  
pp. 7347-7355 ◽  
Author(s):  
X.X. Ma ◽  
Y.P. Feng ◽  
J.L. Liu ◽  
L. Chen ◽  
Y.Q. Zhao ◽  
...  

VirusDisease ◽  
2017 ◽  
Vol 28 (2) ◽  
pp. 156-163 ◽  
Author(s):  
Atul B. Patil ◽  
Vijayendra S. Dalvi ◽  
Akhilesh A. Mishra ◽  
Bal Krishna ◽  
Abdul Azeez

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