scholarly journals Genomic diversity, life strategies and ecology of marine HTVC010P-type pelagiphages

2021 ◽  
Vol 7 (7) ◽  
Author(s):  
Sen Du ◽  
Fang Qin ◽  
Zefeng Zhang ◽  
Zhen Tian ◽  
Mingyu Yang ◽  
...  
Keyword(s):  
Life Cycles ◽  
Genomic Diversity ◽  
Global Ocean ◽  
Comparative Genomic ◽  
Trna Genes ◽  
Life Strategies ◽  
Phage Group ◽  
Integrase Gene ◽  
Subgroup Ii ◽  
Integration Sites

SAR11 bacteria dominate ocean surface bacterioplankton communities, and play an important role in marine carbon and nutrient cycling. The biology and ecology of SAR11 are impacted by SAR11 phages (pelagiphages) that are highly diverse and abundant in the ocean. Among the currently known pelagiphages, HTVC010P represents an extremely abundant but under-studied phage group in the ocean. In this study, we have isolated seven new HTVC010P-type pelagiphages, and recovered 77 nearly full-length HTVC010P-type metagenomic viral genomes from marine metagenomes. Comparative genomic and phylogenomic analyses showed that HTVC010P-type pelagiphages display genome synteny and can be clustered into two major subgroups, with subgroup I consisting of strictly lytic phages and subgroup II mostly consisting of phages with potential lysogenic life cycles. All but one member of the subgroup II contain an integrase gene. Site-specific integration of subgroup II HTVC010P-type pelagiphage was either verified experimentally or identified by in silico genomic sequence analyses, which revealed that various SAR11 tRNA genes can serve as the integration sites of HTVC010P-type pelagiphages. Moreover, HTVC010P-type pelagiphage integration was confirmed by the detection of several Global Ocean Survey (GOS) fragments that contain hybrid phage–host integration sites. Metagenomic recruitment analysis revealed that these HTVC010P-type phages were globally distributed and most lytic subgroup I members exhibited higher relative abundance. Altogether, this study significantly expands our knowledge about the genetic diversity, life strategies and ecology of HTVC010P-type pelagiphages.

scholarly journals Genomic Characterization and Distribution Pattern of a Novel Marine OM43 Phage

2021 ◽  
Vol 12 ◽  
Author(s):  
Mingyu Yang ◽  
Qian Xia ◽  
Sen Du ◽  
Zefeng Zhang ◽  
Fang Qin ◽  
...  
Keyword(s):  
Distribution Pattern ◽  
Sequence Similarity ◽  
Phylogenetic Analyses ◽  
Genomic Diversity ◽  
Comparative Genomic ◽  
Phage Group ◽  
C1 Metabolism ◽  
Subgroup Ii ◽  
A Genome ◽  
Genomic Characterization

Bacteriophages have a significant impact on the structure and function of marine microbial communities. Phages of some major bacterial lineages have recently been shown to dominate the marine viral communities. However, phages that infect many important bacterial clades still remained unexplored. Members of the marine OM43 clade are methylotrophs that play important roles in C1 metabolism. OM43 phages (phages that infect the OM43 bacteria) represent an understudied viral group with only one known isolate. In this study, we describe the genomic characterization and biogeography of an OM43 phage that infects the strain HTCC2181, designated MEP301. MEP301 has a genome size of 34,774 bp. We found that MEP301 is genetically distinct from other known phage isolates and only displays significant sequence similarity with some metagenomic viral genomes (MVGs). A total of 12 MEP301-type MVGs were identified from metagenomic datasets. Comparative genomic and phylogenetic analyses revealed that MEP301-type phages can be separated into two subgroups (subgroup I and subgroup II). We also performed a metagenomic recruitment analysis to determine the relative abundance of reads mapped to these MEP301-type phages, which suggested that subgroup I MEP301-type phages are present predominantly in the cold upper waters with lower salinity. Notably, subgroup II phages have an inverse different distribution pattern, implying that they may infect hosts from a distinct OM43 subcluster. Our study has expanded the knowledge about the genomic diversity of marine OM43 phages and identified a new phage group that is widespread in the ocean.

Draft genome sequence of multidrug-resistant Bradyrhizobium sp. BL isolated from a sewage treatment plant in China

2019 ◽  
Author(s):  
Peng Bao ◽  
Guo-Xiang Li ◽  
Yu-Qin He ◽  
Yi Dai
Keyword(s):  
Antibiotic Resistance ◽  
Municipal Wastewater ◽  
Draft Genome ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Genomic Diversity ◽  
Comparative Genomic ◽  
Municipal Wastewater Treatment ◽  
Total Size ◽  
Bradyrhizobium Sp

Abstract The genus Bradyrhizobium is considered to be widespread and abundant group of symbiotic bacteria in many plant-soil ecosystems. However, the ecological versatility of this phylogenetic group remains highly understudied in man-made ecosystems, mainly due to the lack of pure cultures and genomic data. To further expand our understanding of this genus for human health, we analyzed the high quality draft genome of Bradyrhizobium strain BL, isolated from a municipal wastewater treatment plant in Ningbo, China. The Bradyrhizobium sp. BL draft genome has a total size of 7,718,431 bp with an overall G + C content of 46.43%. From a total of 7236 predicted sequences, 7176 and 60 are protein and RNA coding sequences, respectively. Moreover, 63.51% of the predicted genes were assigned into to Clusters of Orthologous Groups (COG) functional categories. The Bradyrhizobium sp. BL genome contains various defense mechanisms against antibiotics that up to predicted 60 antibiotic resistance coding genes. The Bradyrhizobium sp. BL genome contains 237 termed virulence factors coding genes which show its potential pathogenicity. This study provides important insights into the genomic diversity of the genus Bradyrhizobium and provides a foundation for future comparative genomic studies that will generate a better understanding of the antibiotic resistance process.

scholarly journals Site-Specific Integrative Elements of Rhizobiophage 16-3 Can Integrate into Proline tRNA (CGG) Genes in Different Bacterial Genera

2002 ◽  
Vol 184 (1) ◽  
pp. 177-182 ◽  
Author(s):  
Szabolcs Semsey ◽  
Béla Blaha ◽  
Krisztián Köles ◽  
László Orosz ◽  
Péter P. Papp
Keyword(s):  
Rhizobium Meliloti ◽  
Trna Genes ◽  
Target Sequence ◽  
Integrase Gene ◽  
Site Specific ◽  
Site Specific Recombination ◽  
Tyrosine Recombinases ◽  
Recombination System ◽  
Integrase Protein ◽  
Site Specific Recombination System

ABSTRACT The integrase protein of the Rhizobium meliloti 41 phage 16-3 has been classified as a member of the Int family of tyrosine recombinases. The site-specific recombination system of the phage belongs to the group in which the target site of integration (attB) is within a tRNA gene. Since tRNA genes are conserved, we expected that the target sequence of the site-specific recombination system of the 16-3 phage could occur in other species and integration could take place if the required putative host factors were also provided by the targeted cells. Here we report that a plasmid (pSEM167) carrying the attP element and the integrase gene (int) of the phage can integrate into the chromosomes of R. meliloti 1021 and eight other species. In all cases integration occurred at so-far-unidentified, putative proline tRNA (CGG) genes, indicating the possibility of their common origin. Multiple alignment of the sequences suggested that the location of the att core was different from that expected previously. The minimal attB was identified as a 23-bp sequence corresponding to the anticodon arm of the tRNA.

scholarly journals Characterization and Analysis of the Mitochondrial Genome of Common Bean (Phaseolus vulgaris) by Comparative Genomic Approaches

2020 ◽  
Vol 21 (11) ◽  
pp. 3778
Author(s):  
Changwei Bi ◽  
Na Lu ◽  
Yiqing Xu ◽  
Chunpeng He ◽  
Zuhong Lu
Keyword(s):  
Phaseolus Vulgaris ◽  
Mitochondrial Genome ◽  
Common Bean ◽  
Phylogenetic Analyses ◽  
Complete Mitochondrial Genome ◽  
Rrna Genes ◽  
Comparative Genomic ◽  
Trna Genes ◽  
Leguminous Plants ◽  
The Common

The common bean (Phaseolus vulgaris) is a major source of protein and essential nutrients for humans. To explore the genetic diversity and phylogenetic relationships of P. vulgaris, its complete mitochondrial genome (mitogenome) was sequenced and assembled. The mitogenome is 395,516 bp in length, including 31 unique protein-coding genes (PCGs), 15 transfer RNA (tRNA) genes, and 3 ribosomal RNA (rRNA) genes. Among the 31 PCGs, four genes (mttB, nad1, nad4L, and rps10) use ACG as initiation codons, which are altered to standard initiation codons by RNA editing. In addition, the termination codon CGA in the ccmFC gene is converted to UGA. Selective pressure analysis indicates that the ccmB, ccmFC, rps1, rps10, and rps14 genes were under evolutionary positive selection. The proportions of five amino acids (Phe, Leu, Pro, Arg, and Ser) in the whole amino acid profile of the proteins in each mitogenome can be used to distinguish angiosperms from gymnosperms. Phylogenetic analyses show that P. vulgaris is evolutionarily closer to the Glycininae than other leguminous plants. The results of the present study not only provide an important opportunity to conduct further genomic breeding studies in the common bean, they also provide valuable information for future evolutionary and molecular studies of leguminous plants.

Comparative genomic analysis ofAcidithiobacillus ferrooxidansstrains using theA. ferrooxidansATCC 23270 whole-genome oligonucleotide microarray

2009 ◽  
Vol 55 (5) ◽  
pp. 587-598 ◽  
Author(s):  
Hailang Luo ◽  
Li Shen ◽  
Huaqun Yin ◽  
Qian Li ◽  
Qijiong Chen ◽  
...  
Keyword(s):  
Phylogenetic Tree ◽  
Evolutionary Relationship ◽  
Genomic Analysis ◽  
Oligonucleotide Microarray ◽  
Open Reading Frames ◽  
Genomic Diversity ◽  
Extracellular Polysaccharides ◽  
Comparative Genomic ◽  
Mining Areas ◽  
Main Factor

Acidithiobacillus ferrooxidans is an important microorganism used in biomining operations for metal recovery. Whole-genomic diversity analysis based on the oligonucleotide microarray was used to analyze the gene content of 12 strains of A. ferrooxidans purified from various mining areas in China. Among the 3100 open reading frames (ORFs) on the slides, 1235 ORFs were absent in at least 1 strain of bacteria and 1385 ORFs were conserved in all strains. The hybridization results showed that these strains were highly diverse from a genomic perspective. The hybridization results of 4 major functional gene categories, namely electron transport, carbon metabolism, extracellular polysaccharides, and detoxification, were analyzed. Based on the hybridization signals obtained, a phylogenetic tree was built to analyze the evolution of the 12 tested strains, which indicated that the geographic distribution was the main factor influencing the strain diversity of these strains. Based on the hybridization signals of genes associated with bioleaching, another phylogenetic tree showed an evolutionary relationship from which the co-relation between the clustering of specific genes and geochemistry could be observed. The results revealed that the main factor was geochemistry, among which the following 6 factors were the most important: pH, Mg, Cu, S, Fe, and Al.

scholarly journals A Genomic Islet Mediates Flagellar Phase Variation in Escherichia coli Strains Carrying the Flagellin-Specifying Locus flk

2008 ◽  
Vol 190 (13) ◽  
pp. 4470-4477 ◽  
Author(s):  
Lu Feng ◽  
Bin Liu ◽  
Yanqun Liu ◽  
Yuli A. Ratiner ◽  
Bo Hu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Phase Variation ◽  
Complementation Test ◽  
Direct Repeats ◽  
Integrase Gene ◽  
E Coli ◽  
Chromosomal Genes ◽  
Integration Sites ◽  
First Time ◽  
Transfer Potential

ABSTRACT The occurrence of unilateral flagellar phase variation was previously demonstrated in Escherichia coli strains carrying the non-fliC flagellin-specifying locus flk. In this study, we investigated the mechanism involved in this process. By using sequencing and sequence analysis, the flk region between the chromosomal genes yhaC and rnpB was characterized in all described flk-positive E. coli strains, including the H35 strain identified in this study (the other strains used are H3, H36, H47, and H53 strains), and this region was found to contain a putative integrase gene and flanking direct repeats in addition to the flk flagellin-specifying gene flkA and a fliC repressor gene, flkB, indicating that there is a typical genomic islet (GI), which was designated the flk GI. The horizontal transfer potential of the flk GI was indicated by detection of the excised extrachromosomal circular form of the flk GI. By generating fliC-expressing variants of H3 and H47 strains, unilateral flagellar phase variation in flk-positive strains was shown to be mediated by excision of the flk GI. The function of the proposed integrase gene was confirmed by deletion and a complementation test. The potential integration sites of the flk GI were identified. A general model for flagellar phase variation in flk-positive E. coli strains can be expressed as fliC off + flkA on → fliC on + flkA none. This is the first time that a molecular mechanism for flagellar phase variation has been reported for E. coli.

scholarly journals Survey of Genomic Diversity among Enterococcus faecalis Strains by Microarray-Based Comparative Genomic Hybridization

2007 ◽  
Vol 73 (7) ◽  
pp. 2207-2217 ◽  
Author(s):  
Ågot Aakra ◽  
O. Ludvig Nyquist ◽  
Lars Snipen ◽  
Turid S. Reiersen ◽  
Ingolf F. Nes
Keyword(s):  
Enterococcus Faecalis ◽  
Comparative Genomic Hybridization ◽  
Antibiotic Resistance Genes ◽  
Genomic Diversity ◽  
Comparative Genomic ◽  
Mobile Dna ◽  
Genomic Hybridization ◽  
Promising Tool ◽  
Plasmid Genes ◽  
Harsh Conditions

ABSTRACT We have compared nine Enterococcus faecalis strains with E. faecalis V583 by comparative genomic hybridization using microarrays (CGH). The strains used in this study (the “test” strains) originated from various environments. CGH is a powerful and promising tool for obtaining novel information on genome diversity in bacteria. By CGH, one obtains clues about which genes are present or divergent in the strains, compared to a reference strain (here, V583). The information obtained by CGH is important from both ecological and systematic points of view. CGH of E. faecalis showed considerable diversity in gene content: Compared to V583, the percentage of divergent genes in the test strains varied from 15% to 23%, and 154 genes were divergent in all strains. The main variation was found in regions corresponding to exogenously acquired or mobile DNA in V583. Antibiotic resistance genes, virulence factors, and integrated plasmid genes dominated among the divergent genes. The strains examined showed various contents of genes corresponding to the pTEF1, pTEF2, and pTEF3 genes in V583. The extensive transport and metabolic capabilities of V583 appeared similar in the test strains; CGH indicated that the ability to transport and metabolize various carbohydrates was similar in the test strains (verified by API 50 CH assays). The contents of genes related to stress tolerance appeared similar in V583 and the nine test strains, supporting the view of E. faecalis as an organism able to resist harsh conditions.

scholarly journals Comparative Genomic and Morphological Analyses of Listeria Phages Isolated from Farm Environments

2014 ◽  
Vol 80 (15) ◽  
pp. 4616-4625 ◽  
Author(s):  
Thomas Denes ◽  
Kitiya Vongkamjan ◽  
Hans-Wolfgang Ackermann ◽  
Andrea I. Moreno Switt ◽  
Martin Wiedmann ◽  
...  
Keyword(s):  
New York ◽  
Dairy Farm ◽  
Morphological Diversity ◽  
Genomic Diversity ◽  
Comparative Genomic ◽  
The Novel ◽  
Important Food ◽  
Content Type ◽  
Small Genome ◽  
Food Borne

ABSTRACTThe genusListeriais ubiquitous in the environment and includes the globally important food-borne pathogenListeria monocytogenes. While the genomic diversity ofListeriahas been well studied, considerably less is known about the genomic and morphological diversity ofListeriabacteriophages. In this study, we sequenced and analyzed the genomes of 14Listeriaphages isolated mostly from New York dairy farm environments as well as one relatedEnterococcus faecalisphage to obtain information on genome characteristics and diversity. We also examined 12 of the phages by electron microscopy to characterize their morphology. TheseListeriaphages, based on gene orthology and morphology, together with previously sequencedListeriaphages could be classified into five orthoclusters, including one novel orthocluster. One orthocluster (orthocluster I) consists of large-genome (∼135-kb) myoviruses belonging to the genus “Twort-like viruses,” three orthoclusters (orthoclusters II to IV) contain small-genome (36- to 43-kb) siphoviruses with icosahedral heads, and the novel orthocluster V contains medium-sized-genome (∼66-kb) siphoviruses with elongated heads. A novel orthocluster (orthocluster VI) ofE. faecalisphages, with medium-sized genomes (∼56 kb), was identified, which grouped together and shares morphological features with the novelListeriaphage orthocluster V. This new group of phages (i.e., orthoclusters V and VI) is composed of putative lytic phages that may prove to be useful in phage-based applications for biocontrol, detection, and therapeutic purposes.

Archaeal integrases and mechanisms of gene capture

2004 ◽  
Vol 32 (2) ◽  
pp. 222-226 ◽  
Author(s):  
Q. She ◽  
B. Shen ◽  
L. Chen
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Genome Evolution ◽  
Trna Genes ◽  
Gene Fragment ◽  
Integrase Gene ◽  
Site Specific ◽  
Conjugative Plasmids ◽  
Site Specific Integration ◽  
Target Sites

Archaeal integrases facilitate the formation of two distinctive types of integrated element within archaeal chromosomes: the SSV type and pNOB8 type. The former carries a smaller N-terminal and a larger C-terminal integrase gene fragment, and the latter an intact integrase gene. All integrated elements overlap tRNA genes that were target sites for integration. It has been demonstrated that SSV (Sulfolobus spindle virus) viruses, carrying an SSV-type integrase gene, and conjugative plasmids, carrying a pNOB8-type integrase, are integrative elements. Two mechanisms have been proposed for stably maintaining an integrated element within archaeal chromosomes. There is also evidence for changes having occurred in the captured integrated elements present in archaeal genomes. Thus we infer that site-specific integration constitutes an important mechanism for horizontal gene transfer and genome evolution.

scholarly journals Phylogenomic Network and Comparative Genomics Reveal a Diverged Member of the ϕKZ-Related Group, Marine Vibrio Phage ϕJM-2012

2013 ◽  
Vol 87 (23) ◽  
pp. 12866-12878 ◽  
Author(s):  
Ho Bin Jang ◽  
Fernand F. Fagutao ◽  
Seong Won Nho ◽  
Seong Bin Park ◽  
In Seok Cha ◽  
...  
Keyword(s):  
Structural Changes ◽  
Comparative Genomic ◽  
Tail Fiber ◽  
Phage Group ◽  
Content Type ◽  
Evolutionary Forces ◽  
Related Group ◽  
Highly Correlated ◽  
Conserved Core ◽  
Unique Genes

Bacteriophages are the largest reservoir of genetic diversity. Here we describe the novel phage ϕJM-2012. This natural isolate from marineVibrio cyclitrophicuspossesses very few gene contents relevant to other well-studied marineVibriophages. To better understand its evolutionary history, we built a mathematical model of pairwise relationships among 1,221 phage genomes, in which the genomes (nodes) are linked by edges representing the normalized number of shared orthologous protein families. This weighted network revealed that ϕJM-2012 was connected to only five members of thePseudomonasϕKZ-like phage family in an isolated network, strongly indicating that it belongs to this phage group. However, comparative genomic analyses highlighted an almost complete loss of colinearity with the ϕKZ-related genomes and little conservation of gene order, probably reflecting the action of distinct evolutionary forces on the genome of ϕJM-2012. In this phage, typical conserved core genes, including six RNA polymerase genes, were frequently displaced and the hyperplastic regions were rich in both unique genes and predicted unidirectional promoters with highly correlated orientations. Further, analysis of the ϕJM-2012 genome showed that segments of the conserved N-terminal parts of ϕKZ tail fiber paralogs exhibited evidence of combinatorial assortment, having switched transcriptional orientation, and there was recruitment and/or structural changes among phage endolysins and tail spike protein. Thus, this naturally occurring phage appears to have branched from a common ancestor of the ϕKZ-related groups, showing a distinct genomic architecture and unique genes that most likely reflect adaptation to its chosen host and environment.

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