scholarly journals Reduction of the Rate of Poliovirus Protein Synthesis through Large-Scale Codon Deoptimization Causes Attenuation of Viral Virulence by Lowering Specific Infectivity

2006 ◽  
Vol 80 (19) ◽  
pp. 9687-9696 ◽  
Author(s):  
Steffen Mueller ◽  
Dimitris Papamichail ◽  
J. Robert Coleman ◽  
Steven Skiena ◽  
Eckard Wimmer
Keyword(s):  
Large Scale ◽  
De Novo ◽  
Synonymous Codon ◽  
Direct Analysis ◽  
Synonymous Codon Usage ◽  
Wild Type ◽  
Coding Region ◽  
Virus Particles ◽  
Viral Virulence ◽  
Wide Range

ABSTRACT Exploring the utility of de novo gene synthesis with the aim of designing stably attenuated polioviruses (PV), we followed two strategies to construct PV variants containing synthetic replacements of the capsid coding sequences either by deoptimizing synonymous codon usage (PV-AB) or by maximizing synonymous codon position changes of the existing wild-type (wt) poliovirus codons (PV-SD). Despite 934 nucleotide changes in the capsid coding region, PV-SD RNA produced virus with wild-type characteristics. In contrast, no viable virus was recovered from PV-AB RNA carrying 680 silent mutations, due to a reduction of genome translation and replication below a critical level. After subcloning of smaller portions of the AB capsid coding sequence into the wt background, several viable viruses were obtained with a wide range of phenotypes corresponding to their efficiency of directing genome translation. Surprisingly, when inoculated with equal infectious doses (PFU), even the most replication-deficient viruses appeared to be as pathogenic in PV-sensitive CD155tg (transgenic) mice as the PV(M) wild type. However, infection with equal amounts of virus particles revealed a neuroattenuated phenotype over 100-fold. Direct analysis indicated a striking reduction of the specific infectivity of PV-AB-type virus particles. Due to the distribution effect of many silent mutations over large genome segments, codon-deoptimized viruses should have genetically stable phenotypes, and they may prove suitable as attenuated substrates for the production of poliovirus vaccines.

scholarly journals Complete chloroplast genome of Hordeum brevisubulatum: Genome organization, synonymous codon usage, phylogenetic relationships, and comparative structure analysis

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0261196
Author(s):  
Guangxin Cui ◽  
Chunmei Wang ◽  
Xiaoxing Wei ◽  
Hongbo Wang ◽  
Xiaoli Wang ◽  
...  
Keyword(s):  
Phylogenetic Relationships ◽  
Genome Engineering ◽  
De Novo ◽  
Synonymous Codon ◽  
Northern China ◽  
Synonymous Codon Usage ◽  
The Other ◽  
Coding Regions ◽  
Cp Genome ◽  
Hordeum Brevisubulatum

Background Hordeum brevisubulatum, known as fine perennial forage, is used for soil salinity improvement in northern China. Chloroplast (cp) genome is an ideal model for assessing its genome evolution and the phylogenetic relationships. We de novo sequenced and analyzed the cp genome of H. brevisubulatum, providing a fundamental reference for further studies in genetics and molecular breeding. Results The cp genome of H. brevisubulatum was 137,155 bp in length with a typical quadripartite structure. A total of 130 functional genes were annotated and the gene of accD was lost in the process of evolution. Among all the annotated genes, 16 different genes harbored introns and the genes of ycf3 and rps12 contained two introns. Parity rule 2 (PR2) plot analysis showed that majority of genes had a bias toward T over A in the coding strand in all five Hordeum species, and a slight G over C in the other four Hordeum species except for H. bogdanil. Additionally, 52 dispersed repeat sequences and 182 simple sequence repeats were identified. Moreover, some unique SSRs of each species could be used as molecular markers for further study. Compared to the other four Hordeum species, H. brevisubulatum was most closely related to H. bogdanii and its cp genome was relatively conserved. Moreover, inverted repeat regions (IRa and IRb) were less divergent than other parts and coding regions were relatively conserved compared to non-coding regions. Main divergence was presented at the SSC/IR border. Conclusions This research comprehensively describes the architecture of the H. brevisubulatum cp genome and improves our understanding of its cp biology and genetic diversity, which will facilitate biological discoveries and cp genome engineering.

scholarly journals Platanus_B: an accurate de novo assembler for bacterial genomes using an iterative error-removal process

DNA Research ◽  
2020 ◽  
Vol 27 (3) ◽  
Author(s):  
Rei Kajitani ◽  
Dai Yoshimura ◽  
Yoshitoshi Ogura ◽  
Yasuhiro Gotoh ◽  
Tetsuya Hayashi ◽  
...  
Keyword(s):  
High Resolution ◽  
Large Scale ◽  
De Novo ◽  
Bacterial Genomes ◽  
Long Reads ◽  
Wide Range ◽  
Long Read ◽  
Phylogenomic Analyses ◽  
Error Removal ◽  
Iterative Error

Abstract De novo assembly of short DNA reads remains an essential technology, especially for large-scale projects and high-resolution variant analyses in epidemiology. However, the existing tools often lack sufficient accuracy required to compare closely related strains. To facilitate such studies on bacterial genomes, we developed Platanus_B, a de novo assembler that employs iterations of multiple error-removal algorithms. The benchmarks demonstrated the superior accuracy and high contiguity of Platanus_B, in addition to its ability to enhance the hybrid assembly of both short and nanopore long reads. Although the hybrid strategies for short and long reads were effective in achieving near full-length genomes, we found that short-read-only assemblies generated with Platanus_B were sufficient to obtain ≥90% of exact coding sequences in most cases. In addition, while nanopore long-read-only assemblies lacked fine-scale accuracies, inclusion of short reads was effective in improving the accuracies. Platanus_B can, therefore, be used for comprehensive genomic surveillances of bacterial pathogens and high-resolution phylogenomic analyses of a wide range of bacteria.

Glutton: large-scale integration of non-model organism transcriptome data for comparative analysis

2016 ◽  
Author(s):  
Alan Medlar ◽  
Laura Laakso ◽  
Andreia Miraldo ◽  
Ari Löytynoja
Keyword(s):  
Comparative Analysis ◽  
Large Scale ◽  
De Novo ◽  
Sequence Data ◽  
Model Organism ◽  
Model Organisms ◽  
Rna Seq ◽  
Reference Species ◽  
Wide Range ◽  
The Impact

AbstractHigh-throughput RNA-seq data has become ubiquitous in the study of non-model organisms, but its use in comparative analysis remains a challenge. Without a reference genome for mapping, sequence data has to be de novo assembled, producing large numbers of short, highly redundant contigs. Preparing these assemblies for comparative analyses requires the removal of redundant isoforms, assignment of orthologs and converting fragmented transcripts into gene alignments. In this article we present Glutton, a novel tool to process transcriptome assemblies for downstream evolutionary analyses. Glutton takes as input a set of fragmented, possibly erroneous transcriptome assemblies. Utilising phylogeny-aware alignment and reference data from a closely related species, it reconstructs one transcript per gene, finds orthologous sequences and produces accurate multiple alignments of coding sequences. We present a comprehensive analysis of Glutton’s performance across a wide range of divergence times between study and reference species. We demonstrate the impact choice of assembler has on both the number of alignments and the correctness of ortholog assignment and show substantial improvements over heuristic methods, without sacrificing correctness. Finally, using inference of Darwinian selection as an example of downstream analysis, we show that Glutton-processed RNA-seq data give results comparable to those obtained from full length gene sequences even with distantly related reference species. Glutton is available from http://wasabiapp.org/software/glutton/ and is licensed under the GPLv3.

scholarly journals Synonymous Codon Usages as an Evolutionary Dynamic for Chlamydiaceae

2018 ◽  
Vol 19 (12) ◽  
pp. 4010
Author(s):  
Zhaocai Li ◽  
Wen Hu ◽  
Xiaoan Cao ◽  
Ping Liu ◽  
Youjun Shang ◽  
...  
Keyword(s):  
Amino Acid ◽  
Codon Usage ◽  
Synonymous Codon ◽  
Family Members ◽  
Synonymous Codon Usage ◽  
Amino Acid Usage ◽  
Codon Usage Pattern ◽  
Evolutionary Trend ◽  
Mutation Pressure ◽  
Wide Range

The family of Chlamydiaceae contains a group of obligate intracellular bacteria that can infect a wide range of hosts. The evolutionary trend of members in this family is a hot topic, which benefits our understanding of the cross-infection of these pathogens. In this study, 14 whole genomes of 12 Chlamydia species were used to investigate the nucleotide, codon, and amino acid usage bias by synonymous codon usage value and information entropy method. The results showed that all the studied Chlamydia spp. had A/T rich genes with over-represented A or T at the third positions and G or C under-represented at these positions, suggesting that nucleotide usages influenced synonymous codon usages. The overall codon usage trend from synonymous codon usage variations divides the Chlamydia spp. into four separate clusters, while amino acid usage divides the Chlamydia spp. into two clusters with some exceptions, which reflected the genetic diversity of the Chlamydiaceae family members. The overall codon usage pattern represented by the effective number of codons (ENC) was significantly positively correlated to gene GC3 content. A negative correlation exists between ENC and the codon adaptation index for some Chlamydia species. These results suggested that mutation pressure caused by nucleotide composition constraint played an important role in shaping synonymous codon usage patterns. Furthermore, codon usage of T3ss and Pmps gene families adapted to that of the corresponding genome. Taken together, analyses help our understanding of evolutionary interactions between nucleotide, synonymous codon, and amino acid usages in genes of Chlamydiaceae family members.

scholarly journals The complete chloroplast genome sequence of Morus cathayana and Morus multicaulis, and comparative analysis within genus Morus L

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3037 ◽  
Author(s):  
Wei Qing Kong ◽  
Jin Hong Yang
Keyword(s):  
Codon Usage ◽  
Evolutionary Biology ◽  
Synonymous Codon ◽  
Synonymous Codon Usage ◽  
Mutational Bias ◽  
Coding Region ◽  
Variable Regions ◽  
Standard Curve ◽  
Gene Coding ◽  
Effective Number Of Codons

Trees in the Morus genera belong to the Moraceae family. To better understand the species status of genus Morus and to provide information for studies on evolutionary biology within the genus, the complete chloroplast (cp) genomes of M. cathayana and M. multicaulis were sequenced. The plastomes of the two species are 159,265 bp and 159,103 bp, respectively, with corresponding 83 and 82 simple sequence repeats (SSRs). Similar to the SSRs of M. mongolica and M. indica cp genomes, more than 70% are mononucleotides, ten are in coding regions, and one exhibits nucleotide content polymorphism. Results for codon usage and relative synonymous codon usage show a strong bias towards NNA and NNT codons in the two cp genomes. Analysis of a plot of the effective number of codons (ENc) for five Morus spp. cp genomes showed that most genes follow the standard curve, but several genes have ENc values below the expected curve. The results indicate that both natural selection and mutational bias have contributed to the codon bias. Ten highly variable regions were identified among the five Morus spp. cp genomes, and 154 single-nucleotide polymorphism mutation events were accurately located in the gene coding region.

scholarly journals PDV: an integrative proteomics data viewer

2018 ◽  
Vol 35 (7) ◽  
pp. 1249-1251 ◽  
Author(s):  
Kai Li ◽  
Marc Vaudel ◽  
Bing Zhang ◽  
Yan Ren ◽  
Bo Wen
Keyword(s):  
Large Scale ◽  
De Novo ◽  
Source Code ◽  
Peptide Identification ◽  
Supplementary Information ◽  
Visualization Tool ◽  
Command Line ◽  
Proteomics Data ◽  
Desktop Computers ◽  
Wide Range

Abstract Summary Data visualization plays critical roles in proteomics studies, ranging from quality control of MS/MS data to validation of peptide identification results. Herein, we present PDV, an integrative proteomics data viewer that can be used to visualize a wide range of proteomics data, including database search results, de novo sequencing results, proteogenomics files, MS/MS data in mzML/mzXML format and data from public proteomics repositories. PDV is a lightweight visualization tool that enables intuitive and fast exploration of diverse, large-scale proteomics datasets on standard desktop computers in both graphical user interface and command line modes. Availability and implementation PDV software and the user manual are freely available at http://pdv.zhang-lab.org. The source code is available at https://github.com/wenbostar/PDV and is released under the GPL-3 license. Supplementary information Supplementary data are available at Bioinformatics online.

scholarly journals Targeted transcriptomics reveals signatures of large-scale independent origins and concerted regulation of effector genes in Radopholus similis

2021 ◽  
Vol 17 (11) ◽  
pp. e1010036
Author(s):  
Paulo Vieira ◽  
Roxana Y. Myers ◽  
Clement Pellegrin ◽  
Catherine Wram ◽  
Cedar Hesse ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Large Scale ◽  
De Novo ◽  
Economic Damage ◽  
Radopholus Similis ◽  
Effector Genes ◽  
Wide Range ◽  
Burrowing Nematode ◽  
Generation Sequencing

The burrowing nematode, Radopholus similis, is an economically important plant-parasitic nematode that inflicts damage and yield loss to a wide range of crops. This migratory endoparasite is widely distributed in warmer regions and causes extensive destruction to the root systems of important food crops (e.g., citrus, banana). Despite the economic importance of this nematode, little is known about the repertoire of effectors owned by this species. Here we combined spatially and temporally resolved next-generation sequencing datasets of R. similis to select a list of candidates for the identification of effector genes for this species. We confirmed spatial expression of transcripts of 30 new candidate effectors within the esophageal glands of R. similis by in situ hybridization, revealing a large number of pioneer genes specific to this nematode. We identify a gland promoter motif specifically associated with the subventral glands (named Rs-SUG box), a putative hallmark of spatial and concerted regulation of these effectors. Nematode transcriptome analyses confirmed the expression of these effectors during the interaction with the host, with a large number of pioneer genes being especially abundant. Our data revealed that R. similis holds a diverse and emergent repertoire of effectors, which has been shaped by various evolutionary events, including neofunctionalization, horizontal gene transfer, and possibly by de novo gene birth. In addition, we also report the first GH62 gene so far discovered for any metazoan and putatively acquired by lateral gene transfer from a bacterial donor. Considering the economic damage caused by R. similis, this information provides valuable data to elucidate the mode of parasitism of this nematode.

Identification of myelodysplastic syndrome–specific genes by DNA microarray analysis with purified hematopoietic stem cell fraction

Blood ◽  
2001 ◽  
Vol 98 (2) ◽  
pp. 422-427 ◽  
Author(s):  
Akira Miyazato ◽  
Shuichi Ueno ◽  
Ken Ohmine ◽  
Masuzu Ueda ◽  
Koji Yoshida ◽  
...  
Keyword(s):  
Stem Cell ◽  
Myelodysplastic Syndrome ◽  
Hematopoietic Stem Cell ◽  
Microarray Analysis ◽  
Myeloid Leukemia ◽  
Large Scale ◽  
De Novo ◽  
Hematopoietic Stem ◽  
Wide Range ◽  
Specific Manner

Myelodysplastic syndrome (MDS) is a slowly progressing hematologic malignancy associated with a poor outcome. Despite the relatively high incidence of MDS in the elderly, differentiation of MDS from de novo acute myeloid leukemia (AML) still remains problematic. Identification of genes expressed in an MDS-specific manner would allow the molecular diagnosis of MDS. Toward this goal, AC133 surface marker–positive hematopoietic stem cell (HSC)-like fractions have been collected from a variety of leukemias in a large-scale and long-term genomics project, referred to as “Blast Bank,” and transcriptome of these purified blasts from the patients with MDS were then compared with those from AML through the use of oligonucleotide microarrays. A number of genes were shown to be expressed in a disease-specific manner either to MDS or AML. Among the former found was the gene encoding the protein Delta-like (Dlk) that is distantly related to the Delta-Notch family of signaling proteins. Because overexpression of Dlk may play a role in the pathogenesis of MDS, the disease specificity of Dlk expression was tested by a quantitative “real-time” polymerase chain reaction analysis. Examination of the Blast Bank samples from 22 patients with MDS, 31 with AML, and 8 with chronic myeloid leukemia confirmed the highly selective expression of the Dlk gene in the individuals with MDS. Dlk could be the first candidate molecule to differentiate MDS from AML. The proposal is made that microarray analysis with the Blast Bank samples is an efficient approach to extract transcriptome data of clinical relevance for a wide range of hematologic disorders.

scholarly journals Mutational Disruption ofcis-Acting Replication Element 2C in Coxsackievirus B3 Leads to 5′-Terminal Genomic Deletions

2015 ◽  
Vol 89 (23) ◽  
pp. 11761-11772 ◽  
Author(s):  
S. Smithee ◽  
S. Tracy ◽  
N. M. Chapman
Keyword(s):  
Rna Structure ◽  
De Novo ◽  
Virus Genome ◽  
Viral Rna ◽  
Sequence Information ◽  
Virus Population ◽  
Wild Type ◽  
Coding Region ◽  
Free System ◽  
Genomic Deletions

ABSTRACTFollowing natural human or experimental murine infections and in cell culture, coxsackievirus B (CVB) RNA can persist for weeks in the absence of a cytopathic effect, yet viral RNA remains detectable. Our earlier studies demonstrated that this persistence produced viral RNA with up to 49 nucleotide deletions at the genomic 5′ terminus which partially degraded the cloverleaf (or domain I), an RNA structure required for efficient viral replication. Acis-acting replication element (CRE) in the 2C protein-coding region [CRE(2C)] templates the addition of two uridine residues to the virus genome-encoded RNA replication primer VPg prior to positive-strand synthesis. Because our previous work also demonstrated that the genomes of CVB with a 5′-terminal deletion (CVB-TD) have VPg covalently linked, even though they rarely terminate in the canonical UU donated by CRE(2C)-mediated uridylylation of VPg, we hypothesized that a functional (uridylylating) CRE(2C) would be unnecessary for CVB-TD replication. Using the same 16 mutations in the CVB3 CRE(2C) structure that were considered lethal for this virus by others, we demonstrate here both in infected cell cultures and in mice that wild-type (wt) and CVB3-TD strains carrying these mutations with a nonuridylylating CRE(2C) are viable. While the wt genome with the mutated CRE(2C) displays suppressed replication levels similar to those observed in a CVB3-TD strain, mutation of the CRE(2C) function in a CVB3-TD strain does not further decrease replication. Finally, we show that replication of the parental CVB3 strain containing the mutated CRE(2C) drives thede novogeneration of genomic deletions at the 5′ terminus.IMPORTANCEIn this report, we demonstrate that while CVB can replicate without a uridylylating CRE(2C), the replication rate suffers significantly. Further, deletions at the 5′ terminus of the genome are generated in this virus population, with this virus population supplanting the wild-type population. This demonstrates that VPg can prime without being specifically uridylylated and that this priming is error prone, resulting in the loss of sequence information from the 5′ terminus. These findings have significance when considering the replication of human enteroviruses, and we believe that these data are unattainable in a cell-free system due to the poor replication of these CRE-deficient viruses.

scholarly journals Selection On synonymous Mutations Revealed by 1135 Genomes of Arabidopsis thaliana

2020 ◽  
Vol 16 ◽  
pp. 117693432091679 ◽  
Author(s):  
Lai Wei
Keyword(s):  
Arabidopsis Thaliana ◽  
Synonymous Codon ◽  
Natural Populations ◽  
Gc Content ◽  
Synonymous Codon Usage ◽  
Genome Project ◽  
Allele Frequencies ◽  
Coding Region ◽  
Synonymous Mutations ◽  
Snp Data

Synonymous mutations do not change the amino acid but do change the synonymous codon usage. In genomes of different organisms, the gene conversion process is biased toward GC, which is irrespective of mutation bias. In the coding region, this trend is especially obvious and it is possibly caused by the preference on G/C-ending codons over the A/T-ending ones. If the G/C-ending codons are advantageous, then the synonymous mutations that change A/T to G/C would be “optimal” compared to the opposite ones. In theory, one should observe signals of positive selection on these optimal synonymous mutations. The recently released single-nucleotide polymorphism (SNP) data from the 1001 genome project of Arabidopsis thaliana provided researchers with an unprecedented opportunity to verify this assumption. I fully take advantage of the SNP data from 1,135 A thaliana lines and came to the conclusion that synonymous mutations in natural populations are not strictly neutral: the synonymous mutations that increase GC content (from A/T to G/C) tend to have higher derived allele frequencies (DAFs) and, therefore, are likely to be positively selected. My current study broadens our knowledge of the selection patterns of synonymous mutations and should be appealing to evolutionary biologists. One sentence summary: In 1135 genomes of Arabidopsis thaliana, the synonymous mutations that increase the GC content tend to have higher derived allele frequencies (DAFs) and are likely to be positively selected.

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