scholarly journals Comparative genomic analysis of the secondary flagellar (flag-2) system in the order Enterobacterales

2019 ◽  
Author(s):  
Pieter De Maayer ◽  
Talia Pillay ◽  
Teresa A Coutinho
Keyword(s):  
Evolutionary History ◽  
Potential Role ◽  
Genomic Analysis ◽  
Comparative Genomic ◽  
Flagellar Biosynthesis ◽  
Genomic Analyses ◽  
Variable Feature ◽  
Locomotory Organ ◽  
Protein Number ◽  
Horizontal Acquisition

Abstract Background The order Enterobacterales encompasses a broad range of metabolically and ecologically versatile bacterial taxa, most of which are motile by means of peritrichous flagella. Flagellar biosynthesis has been linked to a primary flagella locus, flag -1, encompassing ~ 50 genes. A discrete locus, flag -2, encoding a distinct flagellar system, has been observed in a limited number of enterobacterial taxa, but its function remains largely uncharacterized.Results and Discussion Comparative genomic analyses showed that orthologous flag -2 loci are present in 592/4,028 taxa belonging to 5/8 and 31/76 families and genera, respectively, in the order Enterobacterales. Furthermore, the presence of the outermost flag- 2 genes only in many taxa suggest that this locus was far more prevalent and has subsequently been lost through gene deletion events. The flag -2 loci range in size from ~3.4 to 81.1 kilobases and code for between five and 102 distinct proteins. The discrepancy in size and protein number can be attributed to the presence of cargo gene islands within the loci. Evolutionary analyses revealed a complex evolutionary history for the flag -2 loci, representing ancestral elements in some taxa, while showing evidence of recent horizontal acquisition in other enterobacteria.Conclusions The flag -2 flagellar system is a relatively common, but highly variable feature among members of the Enterobacterales. Given the energetic burden of flagellar biosynthesis and functioning, the prevalence of a second flagellar system suggests it plays important biological roles in the enterobacteria and we postulate on its potential role as locomotory organ or as secretion system.

scholarly journals Comparative genomic analysis of the secondary flagellar (flag-2) system in the order Enterobacterales

2020 ◽  
Author(s):  
Pieter De Maayer ◽  
Talia Pillay ◽  
Teresa A Coutinho
Keyword(s):  
Evolutionary History ◽  
Potential Role ◽  
Genomic Analysis ◽  
Comparative Genomic ◽  
Flagellar Biosynthesis ◽  
Genomic Analyses ◽  
Variable Feature ◽  
Locomotory Organ ◽  
Protein Number ◽  
Horizontal Acquisition

Abstract Background The order Enterobacterales encompasses a broad range of metabolically and ecologically versatile bacterial taxa, most of which are motile by means of peritrichous flagella. Flagellar biosynthesis has been linked to a primary flagella locus, flag -1, encompassing ~ 50 genes. A discrete locus, flag -2, encoding a distinct flagellar system, has been observed in a limited number of enterobacterial taxa, but its function remains largely uncharacterized. Results and Discussion Comparative genomic analyses showed that orthologous flag -2 loci are present in 592/4,028 taxa belonging to 5/8 and 31/76 families and genera, respectively, in the order Enterobacterales. Furthermore, the presence of only the outermost flag- 2 genes in many taxa suggests that this locus was far more prevalent and has subsequently been lost through gene deletion events. The flag -2 loci range in size from ~3.4 to 81.1 kilobases and code for between five and 102 distinct proteins. The discrepancy in size and protein number can be attributed to the presence of cargo gene islands within the loci. Evolutionary analyses revealed a complex evolutionary history for the flag -2 loci, representing ancestral elements in some taxa, while showing evidence of recent horizontal acquisition in other enterobacteria. Conclusions The flag -2 flagellar system is a fairly common, but highly variable feature among members of the Enterobacterales. Given the energetic burden of flagellar biosynthesis and functioning, the prevalence of a second flagellar system suggests it plays important biological roles in the enterobacteria and we postulate on its potential role as locomotory organ or as secretion system.

scholarly journals Comparative genomic analysis of the secondary flagellar (flag-2) system in the order Enterobacterales

2020 ◽  
Author(s):  
Pieter De Maayer ◽  
Talia Pillay ◽  
Teresa A Coutinho
Keyword(s):  
Evolutionary History ◽  
Potential Role ◽  
Genomic Analysis ◽  
Comparative Genomic ◽  
Flagellar Biosynthesis ◽  
Genomic Analyses ◽  
Variable Feature ◽  
Locomotory Organ ◽  
Protein Number ◽  
Horizontal Acquisition

Abstract Background The order Enterobacterales encompasses a broad range of metabolically and ecologically versatile bacterial taxa, most of which are motile by means of peritrichous flagella. Flagellar biosynthesis has been linked to a primary flagella locus, flag -1, encompassing ~ 50 genes. A discrete locus, flag -2, encoding a distinct flagellar system, has been observed in a limited number of enterobacterial taxa, but its function remains largely uncharacterized.Results and Discussion Comparative genomic analyses showed that orthologous flag -2 loci are present in 592/4,028 taxa belonging to 5/8 and 31/76 families and genera, respectively, in the order Enterobacterales. Furthermore, the presence of only the outermost flag- 2 genes in many taxa suggests that this locus was far more prevalent and has subsequently been lost through gene deletion events. The flag -2 loci range in size from ~3.4 to 81.1 kilobases and code for between five and 102 distinct proteins. The discrepancy in size and protein number can be attributed to the presence of cargo gene islands within the loci. Evolutionary analyses revealed a complex evolutionary history for the flag -2 loci, representing ancestral elements in some taxa, while showing evidence of recent horizontal acquisition in other enterobacteria.Conclusions The flag -2 flagellar system is a fairly common, but highly variable feature among members of the Enterobacterales. Given the energetic burden of flagellar biosynthesis and functioning, the prevalence of a second flagellar system suggests it plays important biological roles in the enterobacteria and we postulate on its potential role as locomotory organ or as secretion system.

scholarly journals Comparative Genomic Analyses of the Vibrio Pathogenicity Island and Cholera Toxin Prophage Regions in Nonepidemic Serogroup Strains of Vibrio cholerae

2003 ◽  
Vol 69 (3) ◽  
pp. 1728-1738 ◽  
Author(s):  
Manrong Li ◽  
Mamuka Kotetishvili ◽  
Yuansha Chen ◽  
Shanmuga Sozhamannan
Keyword(s):  
Cholera Toxin ◽  
Vibrio Cholerae ◽  
Fragment Length Polymorphism ◽  
Pathogenicity Island ◽  
Filamentous Phage ◽  
Comparative Genomic ◽  
Genomic Analyses ◽  
Ctxφ Prophage ◽  
Horizontal Acquisition ◽  
Restriction Fragment Length

ABSTRACT Two major virulence factors are associated with epidemic strains (O1 and O139 serogroups) of Vibrio cholerae: cholera toxin encoded by the ctxAB genes and toxin-coregulated pilus encoded by the tcpA gene. The ctx genes reside in the genome of a filamentous phage (CTXφ), and the tcpA gene resides in a vibrio pathogenicity island (VPI) which has also been proposed to be a filamentous phage designated VPIφ. In order to determine the prevalence of horizontal transfer of VPI and CTXφ among nonepidemic (non-O1 and non-O139 serogroups) V. cholerae, 300 strains of both clinical and environmental origin were screened for the presence of tcpA and ctxAB. In this paper, we present the comparative genetic analyses of 11 nonepidemic serogroup strains which carry the VPI cluster. Seven of the 11 VPI+ strains have also acquired the CTXφ. Multilocus sequence typing and restriction fragment length polymorphism analyses of the VPI and CTXφ prophage regions revealed that the non-O1 and non-O139 strains were genetically diverse and clustered in lineages distinct from that of the epidemic strains. The left end of the VPI in the non-O1 and non-O139 strains exhibited extensive DNA rearrangements. In addition, several CTXφ prophage types characterized by novel repressor (rstR) and ctxAB genes and VPIs with novel tcpA genes were found in these strains. These data suggest that the potentially pathogenic, nonepidemic, non-O1 and non-O139 strains identified in our study most likely evolved by sequential horizontal acquisition of the VPI and CTXφ independently rather than by exchange of O-antigen biosynthesis regions in an existing epidemic strain.

scholarly journals Insights into the Metabolism and Evolution of the Genus Acidiphilium, a Typical Acidophile in Acid Mine Drainage

mSystems ◽  
2020 ◽  
Vol 5 (6) ◽  
Author(s):  
Liangzhi Li ◽  
Zhenghua Liu ◽  
Min Zhang ◽  
Delong Meng ◽  
Xueduan Liu ◽  
...  
Keyword(s):  
Acid Mine Drainage ◽  
Evolutionary History ◽  
Mine Drainage ◽  
Extreme Environments ◽  
Genomic Analysis ◽  
Comparative Genomic Analysis ◽  
Comparative Genomic ◽  
Metabolic Potential ◽  
Ecological Functions ◽  
History Of

ABSTRACT Here, we report three new Acidiphilium genomes, reclassified existing Acidiphilium species, and performed the first comparative genomic analysis on Acidiphilium in an attempt to address the metabolic potential, ecological functions, and evolutionary history of the genus Acidiphilium. In the genomes of Acidiphilium, we found an abundant repertoire of horizontally transferred genes (HTGs) contributing to environmental adaption and metabolic expansion, including genes conferring photosynthesis (puf, puh), CO2 assimilation (rbc), capacity for methane metabolism (mmo, mdh, frm), nitrogen source utilization (nar, cyn, hmp), sulfur compound utilization (sox, psr, sqr), and multiple metal and osmotic stress resistance capacities (czc, cop, ect). Additionally, the predicted donors of horizontal gene transfer were present in a cooccurrence network of Acidiphilium. Genome-scale positive selection analysis revealed that 15 genes contained adaptive mutations, most of which were multifunctional and played critical roles in the survival of extreme conditions. We proposed that Acidiphilium originated in mild conditions and adapted to extreme environments such as acidic mineral sites after the acquisition of many essential functions. IMPORTANCE Extremophiles, organisms that thrive in extreme environments, are key models for research on biological adaption. They can provide hints for the origin and evolution of life, as well as improve the understanding of biogeochemical cycling of elements. Extremely acidophilic bacteria such as Acidiphilium are widespread in acid mine drainage (AMD) systems, but the metabolic potential, ecological functions, and evolutionary history of this genus are still ambiguous. Here, we sequenced the genomes of three new Acidiphilium strains and performed comparative genomic analysis on this extremely acidophilic bacterial genus. We found in the genomes of Acidiphilium an abundant repertoire of horizontally transferred genes (HTGs) contributing to environmental adaption and metabolic ability expansion, as indicated by phylogenetic reconstruction and gene context comparison. This study has advanced our understanding of microbial evolution and biogeochemical cycling in extreme niches.

scholarly journals Sequencing and Comparative Genomic Analysis of pK29, a 269-Kilobase Conjugative Plasmid Encoding CMY-8 and CTX-M-3 β-Lactamases in Klebsiella pneumoniae

2007 ◽  
Vol 51 (8) ◽  
pp. 3004-3007 ◽  
Author(s):  
Ying-Tsong Chen ◽  
Tsai-Ling Lauderdale ◽  
Tsai-Lien Liao ◽  
Yih-Ru Shiau ◽  
Hung-Yu Shu ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Klebsiella Pneumoniae ◽  
Resistance Genes ◽  
Genomic Analysis ◽  
Comparative Genomic Analysis ◽  
Conjugative Plasmid ◽  
Comparative Genomic ◽  
Antimicrobial Resistance Genes ◽  
Genomic Analyses ◽  
The Common

ABSTRACT A 269-kilobase conjugative plasmid, pK29, from a Klebsiella pneumoniae strain was sequenced. The plasmid harbors multiple antimicrobial resistance genes, including those encoding CMY-8 AmpC-type and CTX-M-3 extended-spectrum β-lactamases in the common backbone of IncHI2 plasmids. Mechanisms for dissemination of the resistance genes are highlighted in comparative genomic analyses.

scholarly journals Searching for a “Hidden” Prophage in a Marine Bacterium

2009 ◽  
Vol 76 (2) ◽  
pp. 589-595 ◽  
Author(s):  
Yanlin Zhao ◽  
Kui Wang ◽  
Hans-Wolfgang Ackermann ◽  
Rolf U. Halden ◽  
Nianzhi Jiao ◽  
...  
Keyword(s):  
Sequence Similarity ◽  
Genomic Analysis ◽  
Bioinformatic Analysis ◽  
Open Reading Frames ◽  
Careful Examination ◽  
Comparative Genomic ◽  
Bacterial Genomes ◽  
Genomic Analyses ◽  
Experimental Laboratory ◽  
Bacterial Genes

ABSTRACT Prophages are common in many bacterial genomes. Distinguishing putatively viable prophages from nonviable sequences can be a challenge, since some prophages are remnants of once-functional prophages that have been rendered inactive by mutational changes. In some cases, a putative prophage may be missed due to the lack of recognizable prophage loci. The genome of a marine roseobacter, Roseovarius nubinhibens ISM (hereinafter referred to as ISM), was recently sequenced and was reported to contain no intact prophage based on customary bioinformatic analysis. However, prophage induction experiments performed with this organism led to a different conclusion. In the laboratory, virus-like particles in the ISM culture increased more than 3 orders of magnitude following induction with mitomycin C. After careful examination of the ISM genome sequence, a putative prophage (ISM-pro1) was identified. Although this prophage contains only minimal phage-like genes, we demonstrated that this “hidden” prophage is inducible. Genomic analysis and reannotation showed that most of the ISM-pro1 open reading frames (ORFs) display the highest sequence similarity with Rhodobacterales bacterial genes and some ORFs are only distantly related to genes of other known phages or prophages. Comparative genomic analyses indicated that ISM-pro1-like prophages or prophage remnants are also present in other Rhodobacterales genomes. In addition, the lysis of ISM by this previously unrecognized prophage appeared to increase the production of gene transfer agents (GTAs). Our study suggests that a combination of in silico genomic analyses and experimental laboratory work is needed to fully understand the lysogenic features of a given bacterium.

scholarly journals “Sifarchaeota” a novel Asgard phylum from Costa Rica sediment capable of polysaccharide degradation and anaerobic methylotrophy

2021 ◽  
Author(s):  
Ibrahim F. Farag ◽  
Rui Zhao ◽  
Jennifer F. Biddle
Keyword(s):  
Costa Rica ◽  
Marine Sediments ◽  
Genomic Analysis ◽  
Close Relation ◽  
Comparative Genomic ◽  
Niche Adaptation ◽  
Genomic Analyses ◽  
Ecological Roles ◽  
Costa Rica Margin ◽  
Metagenome Sequencing

The Asgard superphylum is a deeply branching monophyletic group of Archaea, recently described as some of the closest relatives of the eukaryotic ancestor. The wide application of genomic analyses from metagenome sequencing has established six distinct phyla, whose genomes encode for diverse metabolic capacities and play important biogeochemical and ecological roles in marine sediments. Here, we describe two metagenome-assembled genomes (MAGs) recovered from deep marine sediments off Costa Rica margin, defining a novel lineage phylogenetically married to Thorarchaeota, as such we propose the name “Sifarchaeota” for this phylum. The two “Sifarchaeota” MAGs encode for an anaerobic pathway for methylotrophy enabling the utilization of C1-C3 compounds (methanol and methylamines) to synthesize acetyl CoA. The MAGs showed a remarkable saccharolytic capabilities compared to other Asgard lineages and encoded for diverse classes of carbohydrate active enzymes (CAZymes) targeting different mono-, di- and oligosaccharides. Comparative genomic analysis based on the full metabolic profiles of different Asgard lineages revealed the close relation between “Sifarchaeota” and Odinarchaeota MAGs, which suggested similar metabolic potentials and ecological roles. Furthermore, we identified multiple HGT events from different bacterial donors within “Sifarchaetoa” MAGs, which hypothetically expanded “Sifarchaeota” capacities for substrate utilization, energy production and niche adaptation. Importance The exploration of deep marine sediments has unearthed many new lineages of microbes. The finding of this novel phylum of Asgard archaea is important since understanding the diversity and evolution of Asgard archaea may inform also about the evolution of eukaryotic cells. The comparison of metabolic potentials of the Asgard archaea can help inform about selective pressures the lineages have faced during evolution.

scholarly journals The genome of the camphor tree and the genetic and climatic relevance of the top-geoherbalism in this medicinal plant

2021 ◽  
Author(s):  
Rihong Jiang ◽  
Xianlian Chen ◽  
Xuezhu Liao ◽  
Dan Peng ◽  
Xiaoxu Han ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Three Dimensional ◽  
Sister Group ◽  
Cold Season ◽  
Comparative Genomic ◽  
Climate Data ◽  
Volatile Oils ◽  
Expression Of Genes ◽  
Genomic Analyses ◽  
Camphor Tree

Camphor tree (Cinnamomum camphora (L.) J. Presl), a species in the magnoliid family Lauraceae, is known for its rich volatile oils and is used as a medical cardiotonic and as a scent in many perfumed hygiene products. Here, we present a high-quality chromosome-scale genome of C. camphora with a scaffold N50 of 64.34 Mb and an assembled genome size of 755.41 Mb. Phylogenetic inference revealed that the magnoliids are a sister group to the clade of eudicots and monocots. Comparative genomic analyses identified two rounds of ancient whole-genome duplication (WGD). Tandem duplicated genes exhibited a higher evolutionary rate, a more recent evolutionary history and a more clustered distribution on chromosomes, contributing to the production of secondary metabolites, especially monoterpenes and sesquiterpenes, which are the principal essential oil components. Three-dimensional analyses of the volatile metabolites, gene expression and climate data of samples with the same genotype grown in different locations showed that low temperature and low precipitation during the cold season modulate the expression of genes in the terpenoid biosynthesis pathways, especially TPS genes, which facilitates the accumulation of volatile compounds. Our study lays a theoretical foundation for policy-making regarding the agroforestry applications of camphor tree.

scholarly journals Current Progress in Evolutionary Comparative Genomics of Great Apes

2021 ◽  
Vol 12 ◽  
Author(s):  
Aisha Yousaf ◽  
Junfeng Liu ◽  
Sicheng Ye ◽  
Hua Chen
Keyword(s):  
Evolutionary History ◽  
Comparative Genomic ◽  
Great Ape ◽  
Structural Variations ◽  
Genome Sequences ◽  
New Genes ◽  
Genomic Analyses ◽  
Genomic Studies ◽  
High Quality Genome ◽  
Human Specific

The availability of high-quality genome sequences of great ape species provides unprecedented opportunities for genomic analyses. Herein, we reviewed the recent progress in evolutionary comparative genomic studies of the existing great ape species, including human, chimpanzee, bonobo, gorilla, and orangutan. We elaborate discovery on evolutionary history, natural selection, structural variations, and new genes of these species, which is informative for understanding the origin of human-specific phenotypes.

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