scholarly journals Evolutionary responses to codon usage of horizontally transferred genes in Pseudomonas aeruginosa

2020 ◽  
Author(s):  
Martijn Callens ◽  
Celine Scornavacca ◽  
Stéphanie Bedhomme
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Codon Usage ◽  
Core Genome ◽  
Trna Genes ◽  
Compensatory Evolution ◽  
Synonymous Mutations ◽  
The Core ◽  
Selective Retention ◽  
Fitness Benefits ◽  
Core Genes

AbstractProkaryote genome evolution is characterized by the frequent gain of genes through horizontal gene transfer (HGT). For a gene, being horizontally transferred can represent a strong change in its genomic and physiological context. If the codon usage of a transferred gene deviates from that of the receiving organism, the fitness benefits it provides can be reduced due to a mismatch with the expression machinery. Consequently, transferred genes with a deviating codon usage can be selected against or elicit evolutionary responses that enhance their integration. In this study, a comparative genomics approach was used to investigate evolutionary responses after the horizontal transfer of genes with diverse degrees of codon usage mismatch in Pseudomonas aeruginosa. Selection on codon usage of genes acquired through HGT was observed, with the overall codon usage converging towards that of the core genome over evolutionary time. This pattern seemed to be mainly driven by selective retention of transferred genes with an initial codon usage similar to that of the core genes. Gene amelioration, through the accumulation of synonymous mutations after HGT, did not seem to systematically affect transferred genes. Additionally, variation in the copy number of tRNA genes was often associated with the acquisition of genes for which the observed variation could enhance their expression. This provides evidence that compensatory evolution might be an important mechanism for the integration of horizontally transferred genes.

scholarly journals Evolutionary responses to codon usage of horizontally transferred genes in Pseudomonas aeruginosa: gene retention, amelioration and compensatory evolution

2021 ◽  
Vol 7 (6) ◽  
Author(s):  
Martijn Callens ◽  
Celine Scornavacca ◽  
Stéphanie Bedhomme
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Codon Usage ◽  
Bacterial Species ◽  
Trna Genes ◽  
Content Type ◽  
Compensatory Evolution ◽  
Synonymous Mutations ◽  
The Core ◽  
Selective Retention ◽  
Core Genes

Prokaryote genome evolution is characterized by the frequent gain of genes through horizontal gene transfer (HGT). For a gene, being horizontally transferred can represent a strong change in its genomic and physiological context. If the codon usage of a transferred gene deviates from that of the receiving organism, the fitness benefits it provides can be reduced due to a mismatch with the expression machinery. Consequently, transferred genes with a deviating codon usage can be selected against or elicit evolutionary responses that enhance their integration, such as gene amelioration and compensatory evolution. Within bacterial species, the extent and relative importance of these different mechanisms has never been considered altogether. In this study, a phylogeny-based method was used to investigate the occurrence of these different evolutionary responses in Pseudomonas aeruginosa . Selection on codon usage of genes acquired through HGT was observed over evolutionary time, with the overall codon usage converging towards that of the core genome. Gene amelioration, through the accumulation of synonymous mutations after HGT, did not seem to systematically affect transferred genes. This pattern therefore seemed to be mainly driven by selective retention of transferred genes with an initial codon usage similar to that of the core genes. Additionally, variation in the copy number of tRNA genes was often associated with the acquisition of genes for which the observed variation could enhance their expression. This provides evidence that compensatory evolution might be an important mechanism for the integration of horizontally transferred genes.

scholarly journals Why? – Successful Pseudomonas aeruginosa clones with a focus on clone C

2020 ◽  
Vol 44 (6) ◽  
pp. 740-762
Author(s):  
Changhan Lee ◽  
Jens Klockgether ◽  
Sebastian Fischer ◽  
Janja Trcek ◽  
Burkhard Tümmler ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Core Genome ◽  
Genomic Island ◽  
Protein Quality ◽  
Temperature Tolerance ◽  
Protein Homeostasis ◽  
Gene Products ◽  
Accessory Genome ◽  
The Core ◽  
Conserved Core

ABSTRACT The environmental species Pseudomonas aeruginosa thrives in a variety of habitats. Within the epidemic population structure of P. aeruginosa, occassionally highly successful clones that are equally capable to succeed in the environment and the human host arise. Framed by a highly conserved core genome, individual members of successful clones are characterized by a high variability in their accessory genome. The abundance of successful clones might be funded in specific features of the core genome or, although not mutually exclusive, in the variability of the accessory genome. In clone C, one of the most predominant clones, the plasmid pKLC102 and the PACGI-1 genomic island are two ubiquitous accessory genetic elements. The conserved transmissible locus of protein quality control (TLPQC) at the border of PACGI-1 is a unique horizontally transferred compository element, which codes predominantly for stress-related cargo gene products such as involved in protein homeostasis. As a hallmark, most TLPQC xenologues possess a core genome equivalent. With elevated temperature tolerance as a characteristic of clone C strains, the unique P. aeruginosa and clone C specific disaggregase ClpG is a major contributor to tolerance. As other successful clones, such as PA14, do not encode the TLPQC locus, ubiquitous denominators of success, if existing, need to be identified.

scholarly journals A Genomic Survey of Signalling in the Myxococcaceae

2020 ◽  
Vol 8 (11) ◽  
pp. 1739
Author(s):  
David E. Whitworth ◽  
Allison Zwarycz
Keyword(s):  
Core Genome ◽  
Gene Gain ◽  
Fruiting Body Formation ◽  
Two Component System ◽  
Genome Sequences ◽  
The Core ◽  
Accessory Genes ◽  
Two Component ◽  
Gain Loss ◽  
Core Genes

As prokaryotes diverge by evolution, essential ‘core’ genes required for conserved phenotypes are preferentially retained, while inessential ‘accessory’ genes are lost or diversify. We used the recently expanded number of myxobacterial genome sequences to investigate the conservation of their signalling proteins, focusing on two sister genera (Myxococcus and Corallococcus), and on a species within each genus (Myxococcus xanthus and Corallococcus exiguus). Four new C. exiguus genome sequences are also described here. Despite accessory genes accounting for substantial proportions of each myxobacterial genome, signalling proteins were found to be enriched in the core genome, with two-component system genes almost exclusively so. We also investigated the conservation of signalling proteins in three myxobacterial behaviours. The linear carotenogenesis pathway was entirely conserved, with no gene gain/loss observed. However, the modular fruiting body formation network was found to be evolutionarily plastic, with dispensable components in all modules (including components required for fruiting in the model myxobacterium M. xanthus DK1622). Quorum signalling (QS) is thought to be absent from most myxobacteria, however, they generally appear to be able to produce CAI-I (cholerae autoinducer-1), to sense other QS molecules, and to disrupt the QS of other organisms, potentially important abilities during predation of other prokaryotes.

scholarly journals Comparative analysis of probiotic bacteria based on a new definition of core genome

2018 ◽  
Vol 16 (03) ◽  
pp. 1840012 ◽  
Author(s):  
Maria Satti ◽  
Yasuhiro Tanizawa ◽  
Akihito Endo ◽  
Masanori Arita
Keyword(s):  
Stress Responses ◽  
Core Genome ◽  
Public Library ◽  
Orthologous Gene ◽  
Orthologous Group ◽  
Probiotic Properties ◽  
The Core ◽  
Significant Difference ◽  
Definition Of ◽  
Core Genes

The commensal genus Bifidobacterium has probiotic properties. We prepared a public library of the gene functions of the genus Bifidobacterium for its online annotation. Orthologous gene cluster analysis showed that the pan genomes of Bifidobacterium and Lactobacillus exhibit striking similarities when mapped to the Clusters of Orthologous Group (COG) database of proteins. When the core genes in each genus were selected based on our statistical definition of “core genome”, core genes were present in at least 92% of 52 Bifidobacterium and in 97% of 178 Lactobacillus genomes. Functional comparison of the core genes of the two genera revealed a significant difference in the categories “amino acid transport and metabolism” representing their difference in niche specificity. Over-represented Bifidobacterium protein families were primarily involved in host interactions, the complex compound metabolism, and in stress responses. These findings coincide with the published information and validate our bias-resilient definition of the core genome.

scholarly journals Architecture of the superintegron in Vibrio cholerae: identification of core and unique genes

F1000Research ◽  
2013 ◽  
Vol 2 ◽  
pp. 63 ◽  
Author(s):  
Michel A Marin ◽  
Ana Carolina P Vicente
Keyword(s):  
Core Genome ◽  
Position Effect ◽  
Genome Structure ◽  
Enrichment Analysis ◽  
Gene Clusters ◽  
Gene Cassette ◽  
Etiologic Agent ◽  
Functional Genes ◽  
The Core ◽  
Core Genes

Background: Vibrio cholerae, the etiologic agent of cholera, is indigenous to aquatic environments. The V. cholerae genome consists of two chromosomes; the smallest of these harbors a large gene capture and excision system called the superintegron (SI), of ~120 kbp. The flexible nature of the SI that results from gene cassette capture, deletion and rearrangement is thought to make it a hotspot of V. cholerae diversity, but beyond the basic structure it is not clear if there is a core genome in the SI and if so how it is structured. The aim of this study was to explore the core genome structure and the differences in gene content among strains of V. cholerae.Methods: From the complete genomes of seven V. cholerae and one Vibrio mimicus representative strains, we recovered the SI sequences based on the locations of the structural gene IntI4 and the V. cholerae repeats. Analysis of the pangenome, including cluster analysis of functional genes, pangenome profile analysis, genetic variation analysis of functional genes, strain evolution analysis and function enrichment analysis of gene clusters, was performed using a pangenome analysis pipeline in addition to the R scripts, splitsTree4 and genoPlotR.Results and conclusions: Here, we reveal the genetic architecture of the V. cholerae SI. It contains eight core genes when V. mimicus is included and 21 core genes when only V. cholerae strains are considered; many of them are present in several copies. The V. cholerae SI has an open pangenome, which means that V. cholerae may be able to import new gene cassettes to SI. The set of dispensable SI genes is influenced by the niche and type species. The core genes are distributed along the SI, apparently without a position effect.

scholarly journals Heterogeneity among estimates of the core genome and pan-genome in different pneumococcal populations

2017 ◽  
Author(s):  
Andries J van Tonder ◽  
James E Bray ◽  
Keith A Jolley ◽  
Sigríður J Quirk ◽  
Gunnsteinn Haraldsson ◽  
...  
Keyword(s):  
Bacterial Population ◽  
Core Genome ◽  
Bacterial Species ◽  
Essential Point ◽  
Genetic Lineages ◽  
The Core ◽  
Pan Genome ◽  
Single Dataset ◽  
Genomic Regions ◽  
Core Genes

AbstractBackgroundUnderstanding the structure of a bacterial population is essential in order to understand bacterial evolution, or which genetic lineages cause disease, or the consequences of perturbations to the bacterial population. Estimating the core genome, the genes common to all or nearly all strains of a species, is an essential component of such analyses. The size and composition of the core genome varies by dataset, but our hypothesis was that variation between different collections of the same bacterial species should be minimal. To test this, the genome sequences of 3,121 pneumococci recovered from healthy individuals in Reykjavik (Iceland), Southampton (United Kingdom), Boston (USA) and Maela (Thailand) were analysed.ResultsThe analyses revealed a ‘supercore’ genome (genes shared by all 3,121 pneumococci) of only 303 genes, although 461 additional core genes were shared by pneumococci from Reykjavik, Southampton and Boston. Overall, the size and composition of the core genomes and pan-genomes among pneumococci recovered in Reykjavik, Southampton and Boston were very similar, but pneumococci from Maela were distinctly different. Inspection of the pan-genome of Maela pneumococci revealed several >25 Kb sequence regions that were homologous to genomic regions found in other bacterial species.ConclusionsSome subsets of the global pneumococcal population are highly heterogeneous and thus our hypothesis was rejected. This is an essential point of consideration before generalising the findings from a single dataset to the wider pneumococcal population.

scholarly journals Pan-genome of Novel Pantoea stewartii subsp. indologenes Reveal Genes Involved in Onion Pathogenicity and Evidence of Lateral Gene Transfer

2021 ◽  
Author(s):  
Gaurav Agarwal ◽  
Ronald D. Gitaitis ◽  
Bhabesh Dutta
Keyword(s):  
Gene Transfer ◽  
Core Genome ◽  
Foxtail Millet ◽  
Evaluation Study ◽  
Full Spectrum ◽  
The Core ◽  
Pan Genome ◽  
Pantoea Stewartii ◽  
Comparative Phylogenetic Analysis ◽  
Core Genes

Pantoea stewartii subsp. indologenes (Psi) is a causative agent of leafspot of foxtail millet and pearl millet; however, novel strains were recently identified that are pathogenic on onion. Our recent host range evaluation study identified two pathovars; P. stewartii subsp. indologenes pv. cepacicola pv. nov. and P. stewartii subsp. indologenes pv. setariae pv. nov. that are pathogenic on onion and millets or on millets only, respectively. In the current study we developed a pan-genome using the whole genome sequencing of newly identified/classified Psi strains from both pathovars [pv. cepacicola (n= 4) and pv. setariae (n=13)]. The full spectrum of the pan-genome contained 7,030 genes. Among these, 3,546 (present in genomes of all 17 strains) were the core genes that were a subset of 3,682 soft-core genes (present in ≥16 strains). The accessory genome included 1,308 shell genes and 2,040 cloud genes (present in ≤ 2 strains). The pan-genome showed a clear liner progression with >6,000 genes, suggesting the pan-genome of Psi is open. Comparative phylogenetic analysis showed differences in phylogenetic clustering of Pantoea spp. using PAVs/wgMLST approach in comparison to core genome SNP-based phylogeny. Further, we conducted a horizontal gene transfer (HGT) study including four other Pantoea species namely, P. stewartii subsp. stewartii LMG 2715T, P. ananatis LMG 2665T, P. agglomerans LMG L15, and P. allii LMG 24248T. A total of 317 HGT events among four Pantoea species were identified with most gene transfers observed between Psi pv. cepacicola and Psi pv. setariae. Pan-GWAS analysis predicted a total of 154 genes including seven cluster of genes associated with the pathogenicity phenotype on onion. One of the clusters contain 11 genes with known functions and are found to be chromosomally located.

scholarly journals Adding context to the pneumococcal core genes – a bioinformatic analysis of the intergenic pangenome of Streptococcus pneumoniae

2021 ◽  
Author(s):  
Flemming Damgaard Nielsen ◽  
Jakob Møller-Jensen ◽  
Mikkel Girke Jørgensen
Keyword(s):  
Streptococcus Pneumoniae ◽  
Core Genome ◽  
Biological Function ◽  
Bioinformatic Analysis ◽  
Bacterial Pathogenicity ◽  
The Core ◽  
Intergenic Regions ◽  
Crucial Information ◽  
Genetic Context ◽  
Core Genes

AbstractWhole genome sequencing offers great opportunities for linking genotypes to phenotypes aiding in our understanding of human disease and bacterial pathogenicity. However, these analyses often overlook non-coding intergenic regions (IGRs). By disregarding the IGRs, crucial information is lost, as genes have little biological function without expression. In this study, we present the first complete pangenome of the important human pathogen Streptococcus pneumoniae (pneumococcus), spanning both the genes and IGRs. We show that the pneumococcus species retains a small core genome of IGRs that are present across all isolates. Gene expression is highly dependent on these core IGRs, and often several copies of these core IGRs are found across each genome. Core genes and core IGRs show a clear linkage as 81% of core genes are associated with core IGRs. Additionally, we identify a single IGR within the core genome that is always occupied by one of two highly distinct sequences, scattered across the phylogenetic tree. Their distribution indicates that this IGR is transferred between isolates through horizontal regulatory transfer independent of the flanking genes and that each type likely serves different regulatory roles depending on their genetic context.

scholarly journals Development and Application of a Core Genome Multilocus Sequence Typing Scheme for the Health Care-Associated Pathogen Pseudomonas aeruginosa

2020 ◽  
Vol 58 (9) ◽  
Author(s):  
Richard A. Stanton ◽  
Gillian McAllister ◽  
Jonathan B. Daniels ◽  
Erin Breaker ◽  
Nicholas Vlachos ◽  
...  
Keyword(s):  
Health Care ◽  
Pseudomonas Aeruginosa ◽  
Multilocus Sequence Typing ◽  
Core Genome ◽  
Health Care Environment ◽  
Content Type ◽  
Health Care Associated Infections ◽  
Opportunistic Human Pathogen ◽  
The Stability ◽  
Core Genes

ABSTRACT Pseudomonas aeruginosa is an opportunistic human pathogen that frequently causes health care-associated infections (HAIs). Due to its metabolic diversity and ability to form biofilms, this Gram-negative nonfermenting bacterium can persist in the health care environment, which can lead to prolonged HAI outbreaks. We describe the creation of a core genome multilocus sequence typing (cgMLST) scheme to provide a stable platform for the rapid comparison of P. aeruginosa isolates using whole-genome sequencing (WGS) data. We used a diverse set of 58 complete P. aeruginosa genomes to curate a set of 4,440 core genes found in each isolate, representing ∼64% of the average genome size. We then expanded the alleles for each gene using 1,991 contig-level genome sequences. The scheme was used to analyze genomes from four historical HAI outbreaks to compare the phylogenies generated using cgMLST to those of other means (traditional MLST, pulsed-field gel electrophoresis [PFGE], and single-nucleotide variant [SNV] analysis). The cgMLST scheme provides sufficient resolution for analyzing individual outbreaks, as well as the stability for comparisons across a variety of isolates encountered in surveillance studies, making it a valuable tool for the rapid analysis of P. aeruginosa genomes.

Transfer RNA genes and their significance to codon usage in the Pseudomonas aeruginosa lamboid bacteriophage D3

1999 ◽  
Vol 45 (9) ◽  
pp. 791-796 ◽  
Author(s):  
Andrew M Kropinski ◽  
Mary Jo Sibbald
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Codon Usage ◽  
Transfer Rna ◽  
Trna Genes ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Early Region ◽  
Phage Proteins ◽  
Rna Genes

Using tRNAscan-SE and FAStRNA we have identified four tRNA genes in the delayed early region of the bacteriophage D3 genome (GenBank accession No. AF077308). These are specific for methionine (AUG), glycine (GGA), asparagine (AAC), and threonine (ACA). The D3 Thr- and Gly-tRNAs recognize codons, which are rarely used in Pseudomonas aeruginosa and presumably, influence the rate of translation of phage proteins. BLASTN searches revealed that the D3 tRNA genes have homology to tRNA genes from Gram-positive bacteria. Analysis of codon usage in the 91 ORFs discovered in D3 indicates patterns of codon usage reminiscent of Escherichia coli or P. aeruginosa.Key words: bacteriophage, Pseudomonas, D3, tRNA, codon usage.

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