Codon Usage Variation Research Articles

Unravelling Prokaryotic Codon Usage: Insights from Phylogeny, Influencing Factors and Pathogenicity

Analyzing prokaryotic codon usage trends has become a crucial topic of study with significant ramifications for comprehending microbial genetics, classification, evolution, and the control of gene expression. This review study explores the numerous facets of prokaryotic codon usage patterns, looking at different parameters like habitat and lifestyle across broad groups of prokaryotes by emphasizing the role of codon reprogramming in adaptive strategies and its integration into systems biology. We also explored the numerous variables driving codon usage bias, including natural selection, mutation, horizontal gene transfer, codon-anticodon interaction, and genomic composition in prokaryotes through a thorough study of current literature. Furthermore, a special session on codon usage on pathogenic prokaryotes and the role of codon usage in the phylogeny of prokaryotes has been discussed. We also looked at the various software and indices that have been recently applied to prokaryotic genomes. The promising directions that lay ahead to map the future of codon usage research on prokaryotes have been emphasized. Codon usage variations across prokaryotic communities could be better understood by combining environmental, metagenomic, and system biology approaches.

Limited Variation in Codon Usage across Mitochondrial Genomes of Non-Biting Midges (Diptera: Chironomidae).

The codon usage patterns of mitochondrial genomes offer insights into the evolutionary and phylogenetic studies of species. Codon usage analysis has been conducted in a few Chironomidae species, and the codon usage patterns in other species remain ambiguous. We aim to reveal the codon usage differences in the mitochondrial genomes across this family. We sequenced the first mitochondrial genome of the genus Conchapelopia and the third mitochondrial genome of the subfamily Tanypodinae. Then, we analyzed its relative synonymous codon usage and effective number of codons with registered mitochondrial genomes from 28 other genera. The results indicated that there was limited variation in codon usage across five subfamilies, Chironominae, Orthocladiinae, Diamesinae, Prodiamesinae and Tanypodinae. While Parochlus steinenii from Podonominae presented a weaker codon bias, P. steinenii possessed the most genes experiencing natural selection. Additionally, ND1, ND2 and ND3 were found to be the most frequently selected genes across all species. Our findings contribute to further understanding the evolutionary and phylogenetic relationships of Chironomidae.

Stop Codon Usage of Three Gene Families in Selected Medical Insects, and their Phylogenetic Relationships

Medical insects pose significant health risks, transmitting disease causing agents with significant morbidity and mortality globally. Understanding their genetic composition and evolutionary relationship is crucial to developing control techniques to combat them. This study aims to compare the stop codon usage of gustatory, odorant and kinase genes, and assess their use as markers for evaluating the phylogenetic relationship between selected medical insects. Fifteen genes from three gene families including gustatory receptors, odorant receptors, and kinases were studied in thirty-four insect species. Gene and transcript sequences were retrieved from Ensembl Metazoa database. The stop codon usage was obtained by identifying the stop codon present at the end of the transcript sequences. Multiple sequence alignment of the gene sequences was performed and phylogenetic trees were computed. There were variations in the stop codon usage across the different insect species. The odorant receptor and kinase genes grouped the insects into two major clusters. The stop codon usage highlighted the variation within and among the species. The phylogenetic analysis results supported existing insect classification. These approaches could be considered for phylogenetic analyses of other arthropod groups. Accurate measurement of stop codon usage will be important for understanding natural selection, the genetic variation of coding sequences of genes, and useful in design of more efficient expression constructs in gene-editing techniques for vector control.

Intraspecific and interspecific variations in the synonymous codon usage in mitochondrial genomes of 8 pleurotus strains

In this study, we investigated the codon bias of twelve mitochondrial core protein coding genes (PCGs) in eight Pleurotus strains, two of which are from the same species. The results revealed that the codons of all Pleurotus strains had a preference for ending in A/T. Furthermore, the correlation between codon base compositions and codon adaptation index (CAI), codon bias index (CBI) and frequency of optimal codons (FOP) indices was also detected, implying the influence of base composition on codon bias. The two P. ostreatus species were found to have differences in various base bias indicators. The average effective number of codons (ENC) of mitochondrial core PCGs of Pleurotus was found to be less than 35, indicating strong codon preference of mitochondrial core PCGs of Pleurotus. The neutrality plot analysis and PR2-Bias plot analysis further suggested that natural selection plays an important role in Pleurotus codon bias. Additionally, six to ten optimal codons (ΔRSCU > 0.08 and RSCU > 1) were identified in eight Pleurotus strains, with UGU and ACU being the most widely used optimal codons in Pleurotus. Finally, based on the combined mitochondrial sequence and RSCU value, the genetic relationship between different Pleurotus strains was deduced, showing large variations between them. This research has improved our understanding of synonymous codon usage characteristics and evolution of this important fungal group.

Codon usage bias of goose circovirus and its adaptation to host

Goose circovirus (GoCV), a potential immunosuppressive virus possessing a circular single-stranded DNA genome, is widely distributed in both domesticated and wild geese. This virus infection causes significant economic losses in the waterfowl industry. The codon usage patterns of viruses reflect the evolutionary history and genetic architecture, allowing them to adapt quickly to changes in the external environment, particularly to their hosts. In this study, we retrieved the coding sequences (Rep and Cap) and the genome of GoCV from GenBank, conducting comprehensive research to explore the codon usage patterns in 144 GoCV strains. The overall codon usage of the GoCV strains was relatively similar and exhibited a slight bias. The effective number of codons (ENC) indicated a low overall extent of codon usage bias (CUB) in GoCV. Combined with the base composition and relative synonymous codon usage (RSCU) analysis, the results revealed a bias toward A- and G-ending codons in the overall codon usage. Analysis of the ENC-GC3s plot and neutrality plot suggested that natural selection plays an important role in shaping the codon usage pattern of GoCV, with mutation pressure having a minor influence. Furthermore, the correlations between ENC and relative indices, as well as correspondence analysis (COA), showed that hydrophobicity and geographical distribution also contribute to codon usage variation in GoCV, suggesting the possible involvement of natural selection. In conclusion, GoCV exhibits comparatively slight CUB, with natural selection being the major factor shaping the codon usage pattern of GoCV. Our research contributes to a deeper understanding of GoCV evolution and its host adaptation, providing valuable insights for future basic studies and vaccine design related to GoCV.

Re-examining Correlations Between Synonymous Codon Usage and Protein Bond Angles in Escherichia coli.

Rosenberg AA, Marx A, Bronstein AM (Codon-specific Ramachandran plots show amino acid backbone conformation depends on identity of the translated codon. Nat Commun. 2022:13:2815) recently found a surprising correlation between synonymous codon usage and the dihedral bond angles of the resulting amino acid. However, their analysis did not account for the strongest known correlate of codon usage: gene expression. We re-examined the relationship between bond angles and codon usage by applying the approach of Rosenberg et al. to simulated protein-coding sequences that (i) have random codon usage, (ii) codon usage determined by mutation biases, and (iii) maintain the general relationship between codon usage and gene expression via the assumption of selection-mutation-drift equilibrium. We observed correlations between dihedral bond angle and codon usage when codon usage is entirely random, indicating possible conflation of noise with differences in bond angle distributions between synonymous codons. More relevant to the general analysis of codon usage patterns, we found surprisingly good agreement between the analysis of the real sequences and the analysis of sequences simulated assuming selection-mutation-drift equilibrium, with 91% of significant synonymous codon pairs detected in the former were also detected in the latter. We believe the correlation between codon usage and dihedral bond angles resulted from the variation in codon usage across genes due to the interplay between mutation bias, natural selection for translation efficiency, and gene expression, further underscoring these factors must be controlled for when looking for novel patterns related to codon usage.

Comparative analysis of codon usage patterns in the chloroplast genomes of nine forage legumes

Leguminosae is one of the three largest families of angiosperms after Compositae and Orchidaceae. It is widely distributed and grows in a variety of environments, including plains, mountains, deserts, forests, grasslands, and even waters where almost all legumes can be found. It is one of the most important sources of starch, protein and oil in the food of mankind and also an important source of high-quality forage material for animals, which has important economic significance. In our study, the codon usage patterns and variation sources of the chloroplast genome of nine important forage legumes were systematically analyzed. Meanwhile, we also constructed a phylogenetic tree based on the whole chloroplast genomes and protein coding sequences of these nine forage legumes. Our results showed that the chloroplast genomes of nine forage legumes end with A/T bases, and seven identical high-frequency (HF) codons were detected among the nine forage legumes. ENC-GC3s mapping, PR2 analysis, and neutral analysis showed that the codon bias of nine forage legumes was influenced by many factors, among which natural selection was the main influencing factor. The codon usage frequency showed that the Nicotiana tabacum and Saccharomyces cerevisiae can be considered as receptors for the exogenous expression of chloroplast genes of these nine forage legumes. The phylogenetic relationships of the chloroplast genomes and protein coding genes were highly similar, and the nine forage legumes were divided into three major clades. Among the clades Melilotus officinalis was more closely related to Medicago sativa, and Galega officinalis was more closely related to Galega orientalis. This study provides a scientific basis for the molecular markers research, species identification and phylogenetic studies of forage legumes.

Analysis of codon usage patterns in 48 Aconitum species

BackgroundThe Aconitum genus is a crucial member of the Ranunculaceae family. There are 350 Aconitum species worldwide, with about 170 species found in China. These species are known for their various pharmacological effects and are commonly used to treat joint pain, cold abdominal pain, and other ailments. Codon usage bias (CUB) analysis contributes to evolutionary relationships and phylogeny. Based on protein-coding sequences (PCGs), we selected 48 species of Aconitum for CUB analysis.ResultsThe results revealed that Aconitum species had less than 50% GC content. Furthermore, the distribution of GC content was irregular and followed a trend of GC1 > GC2 > GC3, indicating a bias towards A/T bases. The relative synonymous codon usage (RSCU) heat map revealed the presence of conservative codons with slight variations within the genus. The effective number of codons (ENC)-Plot and the parity rule 2 (PR2)-bias plot analysis indicate that natural selection is the primary factor influencing the variation in codon usage. As a result, we screened various optimal codons and found that A/T bases were preferred as the last codon. Furthermore, our Maximum Likelihood (ML) analysis based on PCGs among 48 Aconitum species yielded results consistent with those obtained from complete chloroplast (cp.) genome data. This suggests that analyzing mutation in PCGs is an efficient method for demonstrating the phylogeny of species at the genus level.ConclusionsThe CUB analysis of 48 species of Aconitum was mainly influenced by natural selection. This study reveals the CUB pattern of Aconitum and lays the foundation for future genetic modification and phylogenetic analyses.

Codon usage bias of Venezuelan equine encephalitis virus and its host adaption

Venezuelan equine encephalitis virus (VEEV) is an emerging zoonotic virus in the alphavirus genus. It can be transmitted to humans due to spillover from equid-mosquito cycles. The symptoms caused by VEEV include fever, headache, myalgia, nausea, and vomiting. It can also cause encephalitis in severe cases. The evolutionary features of VEEV are largely unknown. In this study, we comprehensively analyzed the codon usage pattern of VEEV by computing a variety of indicators, such as effective number of codons (ENc), codon adaptation index (CAI), relative synonymous codon usage (RSCU), on 130 VEEV coding sequences retrieved from GenBank. The results showed that the codon usage bias of VEEV is relatively low. ENc-GC3s plot, neutrality plot, and CAI-ENc correlation analyses supported that translational selection plays an important role in shaping the codon usage pattern of VEEV whereas the mutation pressure has a minor influence. Analysis of RSCU values showed that most of the preferred codons in VEEV are C/G-ended. Analysis of dinucleotide composition found that all CG- and UA-containing codons are not preferentially used. Phylogenetic analysis showed that VEEV isolates can be clustered into three genera and evolutionary force affects the codon usage pattern. Furthermore, a correspondence analysis (COA) showed that aromaticity and hydrophobicity as well as geographical distribution also have certain effects on the codon usage variation of VEEV, suggesting the possible involvement of translational selection. Overall, the codon usage of VEEV is comparatively slight and translational selection might be the main factor that shapes the codon usage pattern of VEEV. This study will promote our understanding about the evolution of VEEV and its host adaption, and might provide some clues for preventing the cross-species transmission of VEEV.

Characterization of mitochondrial genome of Indian Ocean blue-spotted maskray, Neotrygon indica and its phylogenetic relationship within Dasyatidae Family

The present study characterized complete mitochondrial genome of Blue-spotted maskray, Neotrygon indica and studied the evolutionary relationship of the species within the Dasyatidae family. The total length of the mitogenome was 17,974 bp including 37 genes and a non-coding control region. The average frequency of nucleotides in protein-coding genes was A: 29.1 %, T: 30.2 %, G: 13.0 % and C: 27.7 % with AT content of 59.3 %. The values of AT and GC skewness were −0.018 and −0.338, respectively. Comparative analyses showed a large number of average synonymous substitutions per synonymous site (Ks) in gene NADH4 (5.07) followed by NADH5 (4.72). High values of average number of non-synonymous substitutions per non-synonymous site (Ka) were observed in genes ATPase8 (0.54) and NADH2 (0.44). Genes NADH4L and NADH2 showed high interspecific genetic distance values of 0.224 ± 0.001 and 0.213 ± 0.002, respectively. Heat map analysis showed variation in codon usage among different species of the Dasyatidae family. The phylogenetic tree showed a sister relationship between the Dasyatinae and the Neotrygoninae subfamilies. Neotrygon indica formed as a sister species to the clade consisting of N. varidens and N. orientalis. Based on the present results, Neotrygon indica could have diverged from the common ancestor of the two latter in the Plio-Pleistocene. The present study showed distinct characteristics of N. indica from its congeners through comparative mitogenomics.

Intragenic codon usage in proteobacteria: Translational selection, IS expansion and genomic shrinkage.

This manuscript presents a method to systematically study intragenic variations in codon usage using correspondence analysis and the effective number of codons. The method is applied to >1100 proteobacteria. Codon usage biases (measured as inertia) increases with genome size, the same is true for the percentage of inertia explained by the first axis. It is shown that there is often a relaxed or more uniform codon usage near the gene termini. Ithis is not seen n small genomes, notably those of intracellular organisms like Buchnera aphidicola or Rickettsia prowazekii where translational selection plays less of a role. When genes from E. coli, for which translational selection is well described, are split into low, intermediate and high expression, respectively, it is shown that the intragenic codon usage pattern with more uniform usage at termini exist across all three expression groups. Furthermore, the correspondence analysis reveals a unique pattern in Bordetella pertussis due to IS expansion. This study thus shows that translational selection, genome shrinkage and IS expansion result in characteristic patterns in intragenic codon usage.

Evolution of Potato virus X

Potato virus X (PVX) is the type potexvirus of economic significance. The pathogen is distributed worldwide, threatening solanaceous plants in particular. Based on the coat protein (CP) gene, PVX isolates are classified into two major genotypes (I and II). To gain more insights into the molecular epidemiology and evolution of PVX, recombination analyses were conducted and significant signals were detected. Bayesian coalescent method was then applied to the time-stamped entire CP sequences. According to the estimates, the global subtype I-1 went into expansion in the 20th century and was evolving at a moderate rate. Based on the CP phylogenies, a divergence scenario was proposed for PVX. Surveys of codon usage variation showed that PVX genes had additional bias independent of compositional constraint. In codon preference, PVX was both similar to and different from the three major hosts, potato (Solanum tuberosum), tobacco (Nicotiana tabacum), and tomato (S. lycopersicum). Moreover, the suppression of CpG and UpA dinucleotide frequencies was observed in PVX.

An extensive evaluation of codon usage pattern and bias of structural proteins p30, p54 and, p72 of the African swine fever virus (ASFV)

The online version contains supplementary material available at 10.1007/s13337-021-00719-x.

Comparative analysis of human coronaviruses focusing on nucleotide variability and synonymous codon usage patterns

The prevailing COVID-19 pandemic has drawn the attention of the scientific community to study the evolutionary origin of Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2). This study is a comprehensive quantitative analysis of the protein-coding sequences of seven human coronaviruses (HCoVs) to decipher the nucleotide sequence variability and codon usage patterns. It is essential to understand the survival ability of the viruses, their adaptation to hosts, and their evolution.The current analysis revealed a high abundance of the relative dinucleotide (odds ratio), GC and CT pairs in the first and last two codon positions, respectively, as well as a low abundance of the CG pair in the last two positions of the codon, which might be related to the evolution of the viruses. A remarkable level of variability of GC content in the third position of the codon among the seven coronaviruses was observed. Codons with high RSCU values are primarily from the aliphatic and hydroxyl amino acid groups, and codons with low RSCU values belong to the aliphatic, cyclic, positively charged, and sulfur-containing amino acid groups. In order to elucidate the evolutionary processes of the seven coronaviruses, a phylogenetic tree (dendrogram) was constructed based on the RSCU scores of the codons. The severe and mild categories CoVs were positioned in different clades. A comparative phylogenetic study with other coronaviruses depicted that SARS-CoV-2 is close to the CoV isolated from pangolins (Manis javanica, Pangolin-CoV) and cats (Felis catus, SARS(r)-CoV). Further analysis of the effective number of codon (ENC) usage bias showed a relatively higher bias for SARS-CoV and MERS-CoV compared to SARS-CoV-2. The ENC plot against GC3 suggested that the mutational bias might have a role in determining the codon usage variation among candidate viruses.A codon adaptability study on a few human host parasites (from different kingdoms), including CoVs, showed a diverse adaptability pattern. SARS-CoV-2 and SARS-CoV exhibit relatively lower but similar codon adaptability compared to MERS-CoV.

Codon usage signatures in the genus Cryptococcus: A complex interplay of gene expression, translational selection and compositional bias

The fungal genus Cryptococcus comprises of several diverse species. The pathogens forming Cryptococcus neoformans/ Cryptococcus gatti species complex are of immense clinical significance owing to the high frequency of infections and deaths globally. Three closely related non-pathogenic species namely, Cryptococcus amylolentus, Cryptococcus wingfieldii and Cryptococcus depauperatus are the non-pathogenic ancestral species from which pathogenic lineages have diverged. In the current study, a comprehensive analysis of factors influencing the codon and amino acid usage bias in six pathogenic and three non-pathogenic species was performed. Our results revealed that though compositional bias played a crucial role, translational selection and gene expression were the key determinants of codon usage variations. Analysis of relative dinucleotide abundance and codon context signatures revealed strict avoidance of TpA dinucleotide across genomes. Multivariate statistical analysis based on codon usage data resulted in discrete clustering of pathogens and non-pathogens which correlated with previous reports on their phylogenetic distribution.

Distinctive features gleaned from the comparative genomes analysis of clinical and non-clinical isolates of Klebsiella pneumoniae.

It is of interest to describe the distinctive features gleaned from the comparative genome analysis of clinical and non-clinical isolates of Klebsiella pneumoniae. The core genome of K. pneumoinae consisted of 3568 genes. Comparative genome analysis shows that mdtABCD, toxin-antitoxin systems are unique to clinical isolates and catB, benA, and transporter genes for citrate utilization are exclusive to non-clinical isolates. We further noted aromatic compound degrading genes in non-clinical isolates unlike in the later isolates. We grouped 88 core genes into 3 groups linked to infections, drug-resistance or xenobiotic metabolism using codon usage variation analysis. It is inferred using the neutrality plot analysis of GC12 with GC3 that codon usage variation is dominant over mutation pressure. Thus, we document data to distinguish clinical and non-clinical isolates of K. pneumoniae using comparative genomes analysis for understanding of genome diversity during speciation.

Comparative analysis of codon usage patterns in chloroplast genomes of six Euphorbiaceae species.

Euphorbiaceae plants are important as suppliers of biodiesel. In the current study, the codon usage patterns and sources of variance in chloroplast genome sequences of six different Euphorbiaceae plant species have been systematically analyzed. Our results revealed that the chloroplast genomes of six Euphorbiaceae plant species were biased towards A/T bases and A/T-ending codons, followed by detection of 17 identical high-frequency codons including GCT, TGT, GAT, GAA, TTT, GGA, CAT, AAA, TTA, AAT, CCT, CAA, AGA, TCT, ACT, TAT and TAA. It was found that mutation pressure was a minor factor affecting the variation of codon usage, however, natural selection played a significant role. Comparative analysis of codon usage frequencies of six Euphorbiaceae plant species with four model organisms reflected that Arabidopsis thaliana, Populus trichocarpa, and Saccharomyces cerevisiae should be considered as suitable exogenous expression receptor systems for chloroplast genes of six Euphorbiaceae plant species. Furthermore, it is optimal to choose Saccharomyces cerevisiae as the exogenous expression receptor. The outcome of the present study might provide important reference information for further understanding the codon usage patterns of chloroplast genomes in other plant species.

Comprehensive analysis of synonymous codon usage patterns in orf3 gene of porcine epidemic diarrhea virus in China

The ORF3 protein of porcine epidemic diarrhea virus (PEDV) is found to function as an ion channel which influences virus virulence and production. Taking consideration of the importance of PEDV orf3 gene, we have performed comprehensive analysis to investigate its synonymous codon usage patterns. In this study, the results of base composition analysis showed A/T rich and G/C poor in PEDV orf3 genes, and the most abundant base was nucleotide T. The relative synonymous codon usage value in each codon revealed that codon usage bias existed. The mean ENC value of each gene was 48.75, indicating a low codon usage bias, as well as a relatively instable change in PEDV orf3 genes. The general correlation analysis between base composition and codon usage bias indicated that mutational bias has an impact on the PEDV codon usage bias. Neutral analysis suggested that natural selection pressure takes a more important influence than mutational bias in shaping codon usage bias. Moreover, other factors including hydrophobicity and aromaticity have been also found to influence the codon usage variation among the PEDV orf3 genes. This study not only represents the most systematic analysis of codon usage patterns in PEDV orf3 genes, but also provides a basic shaping mechanism of the codon usage bias.

Exploring the codon patterns between CCD and NCED genes among different plant species

Plant carotenoid cleavage oxygenase (CCO) is an enzyme which catalyzes carotenoids to apocarotenoid products that are involved in several vital physiological functions. The CCO exists in two forms, namely, CCD (Carotenoid Cleavage Dioxygenase) and NCED (Nine-Cis Epoxycarotenoid Dioxygenase). This paper relates to a comparative study on CCD and NCED genes through phylogeny and codon usage analysis. The result of the phylogenetic analysis indicates a closer relationship between CCD and NCED subclass genes, while the RSCU values indicate a high preference for CUC codon in both CCD and NCED gene families. The mean ENc value of NCED genes was found to be 48.76, suggesting a higher codon bias compared to CCD genes. However, the ENc-GC3S plot suggests that both the gene families are under mutational pressure with variations according to their species-specific role. Similarly, the multivariate analysis also suggests that nucleotide mutation bias influences codon usage. Correlation analysis of Axis I and codon adaptation index values indicate a significant correlation between critical indices. Even though the prominence of the variations in codon usage between the two gene families, they are exerted towards the time-specific functional requirement for that plant species. This is evident from the cleaving roles of these enzymes against various carotenoids at different growth stages. The result of this investigation indicates that CCD and NCED genes are under mutational pressure. This codon bias study paves the way for increasing the production of apocarotenoids, which have a great significance in the industry.

Genetic evolution and codon usage analysis of NKX-2.5 gene governing heart development in some mammals

NKX-2.5 gene is responsible for cardiac development and its targeted disruption apprehends cardiac development at the linear heart tube stage. Bioinformatic analysis was employed to investigate the codon usage pattern and dN/dS of mammalian NKX-2.5 gene. The relative synonymous codon usage analysis revealed variation in codon usage and two synonymous codons namely ATA (Ile) and GTA (Val) were absent in NKX-2.5 gene across selected mammalian species suggesting that these two codons were possibly selected against during evolution. Parity rule 2 analysis of two and four fold amino acids showed CT bias whereas six-fold amino acids revealed GA bias. Neutrality analysis suggests that selection played a prominent role while mutation had a minor role. The dN/dS analysis suggests synonymous substitution played a significant role and it negatively correlated with p-distance of the gene. Purifying natural selection played a dominant role in the genetic evolution of NKX-2.5 gene in mammals.