scholarly journals Pan-Genome Analysis of Human Gastric PathogenH. pylori: Comparative Genomics and Pathogenomics Approaches to Identify Regions Associated with Pathogenicity and Prediction of Potential Core Therapeutic Targets

2015 ◽  
Vol 2015 ◽  
pp. 1-17 ◽  
Author(s):  
Amjad Ali ◽  
Anam Naz ◽  
Siomar C Soares ◽  
Marriam Bakhtiar ◽  
Sandeep Tiwari ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
Therapeutic Targets ◽  
Gene Families ◽  
Gene Repertoire ◽  
Potential Core ◽  
Protein Protein Interaction ◽  
Pan Genome ◽  
H Pylori ◽  
Conserved Gene ◽  
Genome Analyses

Helicobacter pyloriis a human gastric pathogen implicated as the major cause of peptic ulcer and second leading cause of gastric cancer (~70%) around the world. Conversely, an increased resistance to antibiotics and hindrances in the development of vaccines againstH. pyloriare observed. Pan-genome analyses of the global representativeH. pyloriisolates consisting of 39 complete genomes are presented in this paper. Phylogenetic analyses have revealed close relationships among geographically diverse strains ofH. pylori. The conservation among these genomes was further analyzed by pan-genome approach; the predicted conserved gene families (1,193) constitute ~77% of the averageH. pylorigenome and 45% of the global gene repertoire of the species. Reverse vaccinology strategies have been adopted to identify and narrow down the potential core-immunogenic candidates. Total of 28 nonhost homolog proteins were characterized as universal therapeutic targets againstH. pyloribased on their functional annotation and protein-protein interaction. Finally, pathogenomics and genome plasticity analysis revealed 3 highly conserved and 2 highly variable putative pathogenicity islands in all of theH. pylorigenomes been analyzed.

scholarly journals Pan-genome Analyses of 3 Strains of Inonotus obliquus and Prediction of Polysaccharide and Terpenoid Genes

2021 ◽  
Vol 16 (11) ◽  
pp. 1934578X2110609
Author(s):  
Xiaofan Guo ◽  
Shouming Wang
Keyword(s):  
Genome Sequencing ◽  
Molecular Level ◽  
Gene Families ◽  
Core Gene ◽  
Accessory Gene ◽  
Bioactive Substances ◽  
Inonotus Obliquus ◽  
Pan Genome ◽  
Medicinal Fungus ◽  
Genome Analyses

Inonotus obliquus is a rare, edible and medicinal fungus that is widely used as a remedy for various diseases. Its main bioactive substances are polysaccharides and terpenoids. In this study, we characterized and investigated the pan-genome of three strains of I. obliquus. The genome sizes of JL01, HE, and NBRC8681 were 32.04, 29.04, and 31.78 Mb, respectively. There were 6 543 core gene families and 6 197 accessory gene families among the three strains, with 14 polysaccharide-related core gene families and seven accessory gene families. For terpenoids, there were 13 core gene families and 17 accessory gene families. Pan-genome sequencing of I. obliquus has improved our understanding of biological characteristics related to the biosynthesis of polysaccharides and terpenoids at the molecular level, which in turn will enable us to increase the production of polysaccharides and terpenoids by this mushroom.

scholarly journals Additional description and genome analyses of Caenorhabditis auriculariae representing the basal lineage of genus Caenorhabditis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mehmet Dayi ◽  
Natsumi Kanzaki ◽  
Simo Sun ◽  
Tatsuya Ide ◽  
Ryusei Tanaka ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
Morphological Characteristics ◽  
Gene Families ◽  
Single Copy ◽  
Specific Gene ◽  
Protein Coding ◽  
Molecular Phylogenetic ◽  
Tight Association ◽  
Genome Analyses ◽  
Species Specific

AbstractCaenorhabditis auriculariae, which was morphologically described in 1999, was re-isolated from a Platydema mushroom-associated beetle. Based on the re-isolated materials, some morphological characteristics were re-examined and ascribed to the species. In addition, to clarify phylogenetic relationships with other Caenorhabditis species and biological features of the nematode, the whole genome was sequenced and assembled into 109.5 Mb with 16,279 predicted protein-coding genes. Molecular phylogenetic analyses based on ribosomal RNA and 269 single-copy genes revealed the species is closely related to C. sonorae and C. monodelphis placing them at the most basal clade of the genus. C. auriculariae has morphological characteristics clearly differed from those two species and harbours a number of species-specific gene families, indicating its usefulness as a new outgroup species for Caenorhabditis evolutionary studies. A comparison of carbohydrate-active enzyme (CAZy) repertoires in genomes, which we found useful to speculate about the lifestyle of Caenorhabditis nematodes, suggested that C. auriculariae likely has a life-cycle with tight-association with insects.

scholarly journals A 500-year tale of co-evolution, adaptation, and virulence: Helicobacter pylori in the Americas

2020 ◽  
Vol 15 (1) ◽  
pp. 78-92 ◽  
Author(s):  
Zilia Y. Muñoz-Ramirez ◽  
Ben Pascoe ◽  
Alfonso Mendez-Tenorio ◽  
Evangelos Mourkas ◽  
Santiago Sandoval-Motta ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Virulence Genes ◽  
Homo Sapiens ◽  
Gene Families ◽  
Human Populations ◽  
Common Component ◽  
Network Analyses ◽  
The Face ◽  
H Pylori ◽  
Genome Analyses

AbstractHelicobacter pylori is a common component of the human stomach microbiota, possibly dating back to the speciation of Homo sapiens. A history of pathogen evolution in allopatry has led to the development of genetically distinct H. pylori subpopulations, associated with different human populations, and more recent admixture among H. pylori subpopulations can provide information about human migrations. However, little is known about the degree to which some H. pylori genes are conserved in the face of admixture, potentially indicating host adaptation, or how virulence genes spread among different populations. We analyzed H. pylori genomes from 14 countries in the Americas, strains from the Iberian Peninsula, and public genomes from Europe, Africa, and Asia, to investigate how admixture varies across different regions and gene families. Whole-genome analyses of 723 H. pylori strains from around the world showed evidence of frequent admixture in the American strains with a complex mosaic of contributions from H. pylori populations originating in the Americas as well as other continents. Despite the complex admixture, distinctive genomic fingerprints were identified for each region, revealing novel American H. pylori subpopulations. A pan-genome Fst analysis showed that variation in virulence genes had the strongest fixation in America, compared with non-American populations, and that much of the variation constituted non-synonymous substitutions in functional domains. Network analyses suggest that these virulence genes have followed unique evolutionary paths in the American populations, spreading into different genetic backgrounds, potentially contributing to the high risk of gastric cancer in the region.

scholarly journals PangenomeNet: a pan-genome-based network reveals functional modules on antimicrobial resistome for Escherichia coli strains

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Hsuan-Lin Her ◽  
Po-Ting Lin ◽  
Yu-Wei Wu
Keyword(s):  
Escherichia Coli ◽  
Resistance Genes ◽  
Biological Networks ◽  
Functional Organization ◽  
Association Studies ◽  
Functional Network ◽  
Gene Repertoire ◽  
Functional Roles ◽  
Protein Protein Interaction ◽  
Pan Genome

Abstract Background Discerning genes crucial to antimicrobial resistance (AMR) mechanisms is becoming more and more important to accurately and swiftly identify AMR pathogenic strains. Pangenome-wide association studies (e.g. Scoary) identified numerous putative AMR genes. However, only a tiny proportion of the putative resistance genes are annotated by AMR databases or Gene Ontology. In addition, many putative resistance genes are of unknown function (termed hypothetical proteins). An annotation tool is crucially needed in order to reveal the functional organization of the resistome and expand our knowledge of the AMR gene repertoire. Results We developed an approach (PangenomeNet) for building co-functional networks from pan-genomes to infer functions for hypothetical genes. Using Escherichia coli as an example, we demonstrated that it is possible to build co-functional network from its pan-genome using co-inheritance, domain-sharing, and protein–protein-interaction information. The investigation of the network revealed that it fits the characteristics of biological networks and can be used for functional inferences. The subgraph consisting of putative meropenem resistance genes consists of clusters of stress response genes and resistance gene acquisition pathways. Resistome subgraphs also demonstrate drug-specific AMR genes such as beta-lactamase, as well as functional roles shared among multiple classes of drugs, mostly in the stress-related pathways. Conclusions By demonstrating the idea of pan-genome-based co-functional network on the E. coli species, we showed that the network can infer functional roles of the genes, including those without functional annotations, and provides holistic views on the putative antimicrobial resistomes. We hope that the pan-genome network idea can help formulate hypothesis for targeted experimental works.

scholarly journals A2M is a potential core gene in intrahepatic cholangiocarcinoma

BMC Cancer ◽  
2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Guanran Zhang ◽  
Xuyue Liu ◽  
Zhengyang Sun ◽  
Xiaoning Feng ◽  
Haiyan Wang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Survival Analysis ◽  
Protein Interaction ◽  
Intrahepatic Cholangiocarcinoma ◽  
Therapeutic Targets ◽  
Pathway Enrichment Analysis ◽  
Analysis Tool ◽  
Potential Core ◽  
Protein Protein Interaction ◽  
Microarray Datasets

Abstract Background Intrahepatic cholangiocarcinoma (ICC) is a type of malignant tumor ranking the second in the incidence of primary liver cancer following hepatocellular carcinoma. Both the morbidity and mortality have been increasing in recent years. Small duct type of ICC has potential therapeutic targets. But overall, the prognosis of patients with ICC is usually very poor. Methods To search latent therapeutic targets for ICC, we programmatically selected the five most suitable microarray datasets. Then, we made an analysis of these microarray datasets (GSE26566, GSE31370, GSE32958, GSE45001 and GSE76311) collected from the Gene Expression Omnibus (GEO) database. The GEO2R tool was effective to find out differentially expressed genes (DEGs) between ICC and normal tissue. Gene Ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were executed using the Database for Annotation, Visualization and Integrated Discovery (DAVID) v 6.8. The Search Tool for the Retrieval of Interacting Genes (STRING) database was used to analyze protein–protein interaction of these DEGs and protein–protein interaction of these DEGs was modified by Cytoscape3.8.2. Survival analysis was performed using Gene Expression Profiling Interactive Analysis (GEPIA) online analysis tool. Results A total of 28 upregulated DEGs and 118 downregulated DEGs were screened out. Then twenty hub genes were selected according to the connectivity degree. The survival analysis results showed that A2M was closely related to the pathogenesis and prognosis of ICC and was a potential therapeutic target for ICC. Conclusions According to our study, low A2M expression in ICC compared to normal bile duct tissue was an adverse prognostic factor in ICC patients. The value of A2M in the treatment of ICC needs to be further studied.

scholarly journals Plasmids Related to the Symbiotic Nitrogen Fixation Are Not Only Cooperated Functionally but Also May Have Evolved over a Time Span in Family Rhizobiaceae

2020 ◽  
Vol 12 (11) ◽  
pp. 2002-2014
Author(s):  
Ling-Ling Yang ◽  
Zhao Jiang ◽  
Yan Li ◽  
En-Tao Wang ◽  
Xiao-Yang Zhi
Keyword(s):  
Nitrogen Fixation ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Symbiotic Nitrogen Fixation ◽  
Gene Families ◽  
Time Span ◽  
Soil Conditions ◽  
Gene Gain ◽  
Nitrogen Fixing ◽  
Pan Genome

Abstract Rhizobia are soil bacteria capable of forming symbiotic nitrogen-fixing nodules associated with leguminous plants. In fast-growing legume-nodulating rhizobia, such as the species in the family Rhizobiaceae, the symbiotic plasmid is the main genetic basis for nitrogen-fixing symbiosis, and is susceptible to horizontal gene transfer. To further understand the symbioses evolution in Rhizobiaceae, we analyzed the pan-genome of this family based on 92 genomes of type/reference strains and reconstructed its phylogeny using a phylogenomics approach. Intriguingly, although the genetic expansion that occurred in chromosomal regions was the main reason for the high proportion of low-frequency flexible gene families in the pan-genome, gene gain events associated with accessory plasmids introduced more genes into the genomes of nitrogen-fixing species. For symbiotic plasmids, although horizontal gene transfer frequently occurred, transfer may be impeded by, such as, the host’s physical isolation and soil conditions, even among phylogenetically close species. During coevolution with leguminous hosts, the plasmid system, including accessory and symbiotic plasmids, may have evolved over a time span, and provided rhizobial species with the ability to adapt to various environmental conditions and helped them achieve nitrogen fixation. These findings provide new insights into the phylogeny of Rhizobiaceae and advance our understanding of the evolution of symbiotic nitrogen fixation.

scholarly journals Chloroplast genomes in Populus (Salicaceae): comparisons from an intensively sampled genus reveal dynamic patterns of evolution

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jiawei Zhou ◽  
Shuo Zhang ◽  
Jie Wang ◽  
Hongmei Shen ◽  
Bin Ai ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
Population Level ◽  
Gene Content ◽  
Sequencing Data ◽  
Cellular Functions ◽  
Chloroplast Evolution ◽  
Chloroplast Genomes ◽  
Genome Features ◽  
Genome Annotations ◽  
Genome Analyses

AbstractThe chloroplast is one of two organelles containing a separate genome that codes for essential and distinct cellular functions such as photosynthesis. Given the importance of chloroplasts in plant metabolism, the genomic architecture and gene content have been strongly conserved through long periods of time and as such are useful molecular tools for evolutionary inferences. At present, complete chloroplast genomes from over 4000 species have been deposited into publicly accessible databases. Despite the large number of complete chloroplast genomes, comprehensive analyses regarding genome architecture and gene content have not been conducted for many lineages with complete species sampling. In this study, we employed the genus Populus to assess how more comprehensively sampled chloroplast genome analyses can be used in understanding chloroplast evolution in a broadly studied lineage of angiosperms. We conducted comparative analyses across Populus in order to elucidate variation in key genome features such as genome size, gene number, gene content, repeat type and number, SSR (Simple Sequence Repeat) abundance, and boundary positioning between the four main units of the genome. We found that some genome annotations were variable across the genus owing in part from errors in assembly or data checking and from this provided corrected annotations. We also employed complete chloroplast genomes for phylogenetic analyses including the dating of divergence times throughout the genus. Lastly, we utilized re-sequencing data to describe the variations of pan-chloroplast genomes at the population level for P. euphratica. The analyses used in this paper provide a blueprint for the types of analyses that can be conducted with publicly available chloroplast genomes as well as methods for building upon existing datasets to improve evolutionary inference.

scholarly journals Systematic Detection of Large-Scale Multi-Gene Horizontal Transfer in Prokaryotes

2021 ◽  
Author(s):  
Lina Kloub ◽  
Sean Gosselin ◽  
Matthew Fullmer ◽  
Joerg Graf ◽  
J Peter Gogarten ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Large Scale ◽  
Single Gene ◽  
Gene Families ◽  
Microbial Evolution ◽  
Phylogenetic Distance ◽  
Secretion Systems ◽  
Type Iii Secretion Systems ◽  
A Genome ◽  
Conserved Gene

Abstract Horizontal gene transfer (HGT) is central to prokaryotic evolution. However, little is known about the “scale” of individual HGT events. In this work, we introduce the first computational framework to help answer the following fundamental question: How often does more than one gene get horizontally transferred in a single HGT event? Our method, called HoMer, uses phylogenetic reconciliation to infer single-gene HGT events across a given set of species/strains, employs several techniques to account for inference error and uncertainty, combines that information with gene order information from extant genomes, and uses statistical analysis to identify candidate horizontal multi-gene transfers (HMGTs) in both extant and ancestral species/strains. HoMer is highly scalable and can be easily used to infer HMGTs across hundreds of genomes. We apply HoMer to a genome-scale dataset of over 22000 gene families from 103 Aeromonas genomes and identify a large number of plausible HMGTs of various scales at both small and large phylogenetic distances. Analysis of these HMGTs reveals interesting relationships between gene function, phylogenetic distance, and frequency of multi-gene transfer. Among other insights, we find that (i) the observed relative frequency of HMGT increases as divergence between genomes increases, (ii) HMGTs often have conserved gene functions, and (iii) rare genes are frequently acquired through HMGT. We also analyze in detail HMGTs involving the zonula occludens toxin and type III secretion systems. By enabling the systematic inference of HMGTs on a large scale, HoMer will facilitate a more accurate and more complete understanding of HGT and microbial evolution.

scholarly journals Evolutionary Analysis of Cystatins of Early-Emerging Metazoans Reveals a Novel Subtype in Parasitic Cnidarians

Biology ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 110
Author(s):  
Pavla Bartošová-Sojková ◽  
Jiří Kyslík ◽  
Gema Alama-Bermejo ◽  
Ashlie Hartigan ◽  
Stephen D. Atkinson ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
Gene Organization ◽  
Gene Repertoire ◽  
Evolutionary Analysis ◽  
Ancestral Gene ◽  
Protein Architecture ◽  
Basal Metazoan ◽  
Cystatin Gene ◽  
Evolutionary Aspects

The evolutionary aspects of cystatins are greatly underexplored in early-emerging metazoans. Thus, we surveyed the gene organization, protein architecture, and phylogeny of cystatin homologues mined from 110 genomes and the transcriptomes of 58 basal metazoan species, encompassing free-living and parasite taxa of Porifera, Placozoa, Cnidaria (including Myxozoa), and Ctenophora. We found that the cystatin gene repertoire significantly differs among phyla, with stefins present in most of the investigated lineages but with type 2 cystatins missing in several basal metazoan groups. Similar to liver and intestinal flukes, myxozoan parasites possess atypical stefins with chimeric structure that combine motifs of classical stefins and type 2 cystatins. Other early metazoan taxa regardless of lifestyle have only the classical representation of cystatins and lack multi-domain ones. Our comprehensive phylogenetic analyses revealed that stefins and type 2 cystatins clustered into taxonomically defined clades with multiple independent paralogous groups, which probably arose due to gene duplications. The stefin clade split between the subclades of classical stefins and the atypical stefins of myxozoans and flukes. Atypical stefins represent key evolutionary innovations of the two parasite groups for which their origin might have been linked with ancestral gene chimerization, obligate parasitism, life cycle complexity, genome reduction, and host immunity.

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