scholarly journals Identification of the optimal codons for acetolactate synthase from weeds: an in-silico study  

Author(s):  
Madhab Kumar Sen ◽  
Kateřina Hamouzová ◽  
Sunil Kanti Mondal ◽  
Josef Soukup

Although various studies of codon usage bias have been reported in a broad spectrum of organisms, no studies to date have examined codon usage bias for herbicide target genes. In this study, we analysed codon usage patterns for the acetolactate synthase (ALS) gene in eight monocot weeds and one model monocot. The base composition at the third codon position follows C3 > G3 > T3 > A3. The values of the effective number of codons (ENC or Nc) indicate low bias, and ENC or Nc vs. GC3 plot suggests that this low bias is due to mutational pressure. Low codon adaptation index and codon bias index values further supported the phenomenon of low bias. Additionally, the optimal codons, along with over- and under-represented codons, were identified. Gene design using optimal codons rather than overall abundant codons produce improved protein expression results. Our results can be used for further studies, including eliciting the mechanisms of herbicide resistance (occurring due to elevation of gene expression levels) and the development of new compounds, their efficiency and risk assessment for herbicide resistance evolution.  

Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 912
Author(s):  
Saadullah Khattak ◽  
Mohd Ahmar Rauf ◽  
Qamar Zaman ◽  
Yasir Ali ◽  
Shabeen Fatima ◽  
...  

The ongoing outbreak of coronavirus disease COVID-19 is significantly implicated by global heterogeneity in the genome organization of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The causative agents of global heterogeneity in the whole genome of SARS-CoV-2 are not well characterized due to the lack of comparative study of a large enough sample size from around the globe to reduce the standard deviation to the acceptable margin of error. To better understand the SARS-CoV-2 genome architecture, we have performed a comprehensive analysis of codon usage bias of sixty (60) strains to get a snapshot of its global heterogeneity. Our study shows a relatively low codon usage bias in the SARS-CoV-2 viral genome globally, with nearly all the over-preferred codons’ A.U. ended. We concluded that the SARS-CoV-2 genome is primarily shaped by mutation pressure; however, marginal selection pressure cannot be overlooked. Within the A/U rich virus genomes of SARS-CoV-2, the standard deviation in G.C. (42.91% ± 5.84%) and the GC3 value (30.14% ± 6.93%) points towards global heterogeneity of the virus. Several SARS-CoV-2 viral strains were originated from different viral lineages at the exact geographic location also supports this fact. Taking all together, these findings suggest that the general root ancestry of the global genomes are different with different genome’s level adaptation to host. This research may provide new insights into the codon patterns, host adaptation, and global heterogeneity of SARS-CoV-2.


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.


Genes ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1169
Author(s):  
Xin Li ◽  
Xiaocen Wang ◽  
Pengtao Gong ◽  
Nan Zhang ◽  
Xichen Zhang ◽  
...  

Giardia duodenalis, a flagellated parasitic protozoan, the most common cause of parasite-induced diarrheal diseases worldwide. Codon usage bias (CUB) is an important evolutionary character in most species. However, G. duodenalis CUB remains unclear. Thus, this study analyzes codon usage patterns to assess the restriction factors and obtain useful information in shaping G. duodenalis CUB. The neutrality analysis result indicates that G. duodenalis has a wide GC3 distribution, which significantly correlates with GC12. ENC-plot result—suggesting that most genes were close to the expected curve with only a few strayed away points. This indicates that mutational pressure and natural selection played an important role in the development of CUB. The Parity Rule 2 plot (PR2) result demonstrates that the usage of GC and AT was out of proportion. Interestingly, we identified 26 optimal codons in the G. duodenalis genome, ending with G or C. In addition, GC content, gene expression, and protein size also influence G. duodenalis CUB formation. This study systematically analyzes G. duodenalis codon usage pattern and clarifies the mechanisms of G. duodenalis CUB. These results will be very useful to identify new genes, molecular genetic manipulation, and study of G. duodenalis evolution.


2021 ◽  
Author(s):  
Neetu Tyagi ◽  
Rahila Sardar ◽  
Dinesh Gupta

AbstractThe Coronavirus disease 2019 (COVID-19) outbreak caused by Severe Acute Respiratory Syndrome Coronavirus 2 virus (SARS-CoV-2) poses a worldwide human health crisis, causing respiratory illness with a high mortality rate. To investigate the factors governing codon usage bias in all the respiratory viruses, including SARS-CoV-2 isolates from different geographical locations (~62K), including two recently emerging strains from the United Kingdom (UK), i.e., VUI202012/01 and South Africa (SA), i.e., 501.Y.V2 codon usage bias (CUBs) analysis was performed. The analysis includes RSCU analysis, GC content calculation, ENC analysis, dinucleotide frequency and neutrality plot analysis. We were motivated to conduct the study to fulfil two primary aims: first, to identify the difference in codon usage bias amongst all SARS-CoV-2 genomes and, secondly, to compare their CUBs properties with other respiratory viruses. A biased nucleotide composition was found as most of the highly preferred codons were A/U-ending in all the respiratory viruses studied here. Compared with the human host, the RSCU analysis led to the identification of 11 over-represented codons and 9 under-represented codons in SARS-CoV-2 genomes. Correlation analysis of ENC and GC3s revealed that mutational pressure is the leading force determining the CUBs. The present study results yield a better understanding of codon usage preferences for SARS-CoV-2 genomes and discover the possible evolutionary determinants responsible for the biases found among the respiratory viruses, thus unveils a unique feature of the SARS-CoV-2 evolution and adaptation. To the best of our knowledge, this is the first attempt at comparative CUBs analysis on the worldwide genomes of SARS-CoV-2, including novel emerged strains and other respiratory viruses.


Author(s):  
Prajakta P Kokate ◽  
Stephen M Techtmann ◽  
Thomas Werner

Abstract Codon usage bias, where certain codons are used more frequently than their synonymous counterparts, is an interesting phenomenon influenced by three evolutionary forces: mutation, selection, and genetic drift. To better understand how these evolutionary forces affect codon usage bias, an extensive study to detect how codon usage patterns change across species is required. This study investigated 668 single-copy orthologous genes independently in 29 Drosophila species to determine how the codon usage patterns change with phylogenetic distance. We found a strong correlation between phylogenetic distance and codon usage bias and observed striking differences in codon preferences between the two subgenera Drosophila and Sophophora. As compared to the subgenus Sophophora, species of the subgenus Drosophila showed reduced codon usage bias and a reduced preference specifically for codons ending with C, except for codons with G in the second position. We found that codon usage patterns in all species were influenced by the nucleotides in the codon's 2nd and 3rd positions rather than the biochemical properties of the amino acids encoded. We detected a concordance between preferred codons and preferred dinucleotides (at positions 2 and 3 of codons). Furthermore, we observed an association between speciation, codon preferences, and dinucleotide preferences. Our study provides the foundation to understand how selection acts on dinucleotides to influence codon usage bias.


Author(s):  
Boyun Yang ◽  
Huolin Luo ◽  
Yuan Tao ◽  
Wenjing Yu ◽  
Liping Luo

Cymbidium kanran is an important commercially grown member of the Chinese orchid family. However, little information regarding the molecular biology of this species is available. In this study, the C. kanran root, shoot, stem, leaf, and flower transcriptomes were sequenced with the Illumina HiSeq 4000 system, which resulted in 8.9 Gb of clean reads that were assembled into 74,620 unigenes, with an average length and N50 of 983 bp and 1,640 bp, respectively. The screening of seven databases (NR, NT, GO, KOG, KEGG, Swiss-Prot, and InterPro) for similar sequences resulted in the functional annotation of 49,813 unigenes. Additionally, 173 MADS-box genes, which help to control major aspects of plant development, were identified and their codon usage bias was analyzed. Only 26 genes had a low ENC (less than or equal to 35), suggesting the codon usage bias was weak. Base mutations were the major determinants of codon usage, although natural selection pressure also influenced codon usage bias. Moreover, 22 optimal codons were identified based on ΔRSCU, and 20 codons ended with A/U. The results of this study provide the foundation for the molecular breeding of new varieties


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.


Viruses ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 331 ◽  
Author(s):  
Kajal Biswas ◽  
Supratik Palchoudhury ◽  
Prosenjit Chakraborty ◽  
Utpal Bhattacharyya ◽  
Dilip Ghosh ◽  
...  

Citrus tristeza virus (CTV), a member of the aphid-transmitted closterovirus group, is the causal agent of the notorious tristeza disease in several citrus species worldwide. The codon usage patterns of viruses reflect the evolutionary changes for optimization of their survival and adaptation in their fitness to the external environment and the hosts. The codon usage adaptation of CTV to specific citrus hosts remains to be studied; thus, its role in CTV evolution is not clearly comprehended. Therefore, to better explain the host–virus interaction and evolutionary history of CTV, the codon usage patterns of the coat protein (CP) genes of 122 CTV isolates originating from three economically important citrus hosts (55 isolate from Citrus sinensis, 38 from C. reticulata, and 29 from C. aurantifolia) were studied using several codon usage indices and multivariate statistical methods. The present study shows that CTV displays low codon usage bias (CUB) and higher genomic stability. Neutrality plot and relative synonymous codon usage analyses revealed that the overall influence of natural selection was more profound than that of mutation pressure in shaping the CUB of CTV. The contribution of high-frequency codon analysis and codon adaptation index value show that CTV has host-specific codon usage patterns, resulting in higheradaptability of CTV isolates originating from C. reticulata (Cr-CTV), and low adaptability in the isolates originating from C. aurantifolia (Ca-CTV) and C. sinensis (Cs-CTV). The combination of codon analysis of CTV with citrus genealogy suggests that CTV evolved in C. reticulata or other Citrus progenitors. The outcome of the study enhances the understanding of the factors involved in viral adaptation, evolution, and fitness toward their hosts. This information will definitely help devise better management strategies of CTV.


2012 ◽  
Vol 60 (5) ◽  
pp. 461 ◽  
Author(s):  
Yuerong Zhang ◽  
Xiaojun Nie ◽  
Xiaoou Jia ◽  
Cunzhen Zhao ◽  
Siddanagouda S. Biradar ◽  
...  

Codon usage patterns of 23 Poaceae chloroplast genomes were analysed in this study. Neutrality analysis indicated that the codon usage patterns have significant correlations with GC12 and GC3 and also showed strong bias towards a high representation of NNA and NNT codons. The Nc-plot showed that although a large proportion of points follow the parabolic line of trajectory, several genes with low ENc values lie below the expected curve, suggesting that mutational bias played a major role in the codon biology of the Poaceae chloroplast genome. Parity Rule 2 plot analysis showed that T was used more frequently than A in all the genomes. Correspondence analysis of relative synonymous codon usage indicated that the first axis explained only a partial amount of variation of codon usage. Furthermore, the gene length and expression level were also found to drive codon usage variation. These findings revealed that besides natural selection, other factors might also exert some influences in shaping the codon usage bias in Poaceae chloroplast genomes. The optimal codons of these 23 genomes were also identified in this study.


2017 ◽  
Vol 9 (9) ◽  
pp. 56
Author(s):  
Wenhan Hu ◽  
Shuhong Wei

Analyzing codon usage bias of WAG-2 gene in wheat three-pistil (TP) mutant may provide a basis for selecting the appropriate host expression systems to improve the expression of target genes. In the present study, we analyzed the codon bias of the complete coding sequence (CDS) of the WAG-2 gene in TP using Codon W program, and compared the results with AGAMOUS (AG) group genes of other plant species. Results showed that the WAG-2 gene in TP and other monocot AG group genes preferably used codons ending with G/C bases, but Arabidopsis thaliana, Nicotiana tabacum, and other dicot crops were biased toward the synonymous codons with A/T. The clustering results based on codon bias were consistent with those based on CDS of the AG group genes, indicating that the difference in codon preference of AG group genes sequences was closely associated with the genetic relationship of the species. The Euclidean distance coefficients of WAG-2 with A. thaliana and N. tabacum were 9.255 and 5.730, respectively, indicating that N. tabacum may be more suitable for the expression of WAG-2. There were 37 codons showing distinct usage differences between WAG-2 and genome of yeast, 23 between WAG-2 and Escherichia coli. Therefore, the E. coli was the superior protein expression system. These results may improve our understanding of codon usage bias and functional studies of WAG-2.


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