Genome sequencing and comparative genomics analysis of Halomonas sp. MT13 reveal genetic adaptation to deep-sea environment

Phytopathogenic Ascomycota are responsible for substantial economic losses each year, destroying valuable crops. The present study aims to provide new insights into phytopathogenicity in Ascomycota from a comparative genomic perspective. This has been achieved by categorizing orthologous gene groups (orthogroups) from 68 phytopathogenic and 24 non-phytopathogenic Ascomycota genomes into three classes: Core, (pathogen or non-pathogen) group-specific, and genome-specific accessory orthogroups. We found that (i) ~20% orthogroups are group-specific and accessory in the 92 Ascomycota genomes, (ii) phytopathogenicity is not phylogenetically determined, (iii) group-specific orthogroups have more enriched functional terms than accessory orthogroups and this trend is particularly evident in phytopathogenic fungi, (iv) secreted proteins with signal peptides and horizontal gene transfers (HGTs) are the two functional terms that show the highest occurrence and significance in group-specific orthogroups, (v) a number of other functional terms are also identified to have higher significance and occurrence in group-specific orthogroups. Overall, our comparative genomics analysis determined positive enrichment existing between orthogroup classes and revealed a prediction of what genomic characteristics make an Ascomycete phytopathogenic. We conclude that genes shared by multiple phytopathogenic genomes are more important for phytopathogenicity than those that are unique in each genome.

Download Full-text

Phylogenomic Insights into Distribution and Adaptation of Bdellovibrionota in Marine Waters

Microorganisms ◽

10.3390/microorganisms9040757 ◽

2021 ◽

Vol 9 (4) ◽

pp. 757

Author(s):

Qing-Mei Li ◽

Ying-Li Zhou ◽

Zhan-Fei Wei ◽

Yong Wang

Keyword(s):

Comparative Genomics ◽

Deep Sea ◽

Binding Protein ◽

Glycerol Metabolism ◽

Metabolic Reconstruction ◽

Type Ii Secretion ◽

Phylogenetic Groups ◽

Genes Encoding ◽

Epipelagic Zone ◽

Chitin Binding Protein

Bdellovibrionota is composed of obligate predators that can consume some Gram-negative bacteria inhabiting various environments. However, whether genomic traits influence their distribution and marine adaptation remains to be answered. In this study, we performed phylogenomics and comparative genomics studies using 132 Bdellovibrionota genomes along with five metagenome-assembled genomes (MAGs) from deep sea zones. Four phylogenetic groups, Oligoflexia, Bdello-group1, Bdello-group2 and Bacteriovoracia, were revealed by constructing a phylogenetic tree, of which 53.84% of Bdello-group2 and 48.94% of Bacteriovoracia were derived from the ocean. Bacteriovoracia was more prevalent in deep sea zones, whereas Bdello-group2 was largely distributed in the epipelagic zone. Metabolic reconstruction indicated that genes involved in chemotaxis, flagellar (mobility), type II secretion system, ATP-binding cassette (ABC) transporters and penicillin-binding protein were necessary for the predatory lifestyle of Bdellovibrionota. Genes involved in glycerol metabolism, hydrogen peroxide (H2O2) degradation, cell wall recycling and peptide utilization were ubiquitously present in Bdellovibrionota genomes. Comparative genomics between marine and non-marine Bdellovibrionota demonstrated that betaine as an osmoprotectant is probably widely used by marine Bdellovibrionota, and all the marine genomes have a number of genes for adaptation to marine environments. The genes encoding chitinase and chitin-binding protein were identified for the first time in Oligoflexia, which implied that Oligoflexia may prey on a wider spectrum of microbes. This study expands our knowledge on adaption strategies of Bdellovibrionota inhabiting deep seas and the potential usage of Oligoflexia for biological control.

Download Full-text

E. coli NF73-1 Isolated From NASH Patients Aggravates NAFLD in Mice by Translocating Into the Liver and Stimulating M1 Polarization

Frontiers in Cellular and Infection Microbiology ◽

10.3389/fcimb.2020.535940 ◽

2020 ◽

Vol 10 ◽

Author(s):

Yifan Zhang ◽

Weiwei Jiang ◽

Jun Xu ◽

Na Wu ◽

Yang Wang ◽

...

Keyword(s):

Gene Expression ◽

Comparative Genomics ◽

Whole Genome Sequencing ◽

Genome Sequencing ◽

Normal Diet ◽

Specific Gene ◽

Whole Genome ◽

Metabolic Switch ◽

M1 Macrophages ◽

E Coli

ObjectiveThe gut microbiota is associated with nonalcoholic fatty liver disease (NAFLD). We isolated the Escherichia coli strain NF73-1 from the intestines of a NASH patient and then investigated its effect and underlying mechanism.Methods16S ribosomal RNA (16S rRNA) amplicon sequencing was used to detect bacterial profiles in healthy controls, NAFLD patients and NASH patients. Highly enriched E. coli strains were cultured and isolated from NASH patients. Whole-genome sequencing and comparative genomics were performed to investigate gene expression. Depending on the diet, male C57BL/6J mice were further grouped in normal diet (ND) and high-fat diet (HFD) groups. To avoid disturbing the bacterial microbiota, some of the ND and HFD mice were grouped as “bacteria-depleted” mice and treated with a cocktail of broad-spectrum antibiotic complex (ABX) from the 8th to 10th week. Then, E. coli NF73-1, the bacterial strain isolated from NASH patients, was administered transgastrically for 6 weeks to investigate its effect and mechanism in the pathogenic progression of NAFLD.ResultsThe relative abundance of Escherichia increased significantly in the mucosa of NAFLD patients, especially NASH patients. The results from whole-genome sequencing and comparative genomics showed a specific gene expression profile in E. coli strain NF73-1, which was isolated from the intestinal mucosa of NASH patients. E. coli NF73-1 accelerates NAFLD independently. Only in the HFD-NF73-1 and HFD-ABX-NF73-1 groups were EGFP-labeled E. coli NF73-1 detected in the liver and intestine. Subsequently, translocation of E. coli NF73-1 into the liver led to an increase in hepatic M1 macrophages via the TLR2/NLRP3 pathway. Hepatic M1 macrophages induced by E. coli NF73-1 activated mTOR-S6K1-SREBP-1/PPAR-α signaling, causing a metabolic switch from triglyceride oxidation toward triglyceride synthesis in NAFLD mice.ConclusionsE. coli NF73-1 is a critical trigger in the progression of NAFLD. E. coli NF73-1 might be a specific strain for NAFLD patients.

Download Full-text

Meeting Highlights: Genome Sequencing and Biology 2001

Comparative and Functional Genomics ◽

10.1002/cfg.97 ◽

2001 ◽

Vol 2 (4) ◽

pp. 243-251

Author(s):

Jo Wixon

Keyword(s):

Comparative Genomics ◽

Functional Genomics ◽

Genome Sequencing ◽

Large Scale ◽

Model Organism

We bring you a report from the CSHL Genome Sequencing and Biology Meeting, which has a long and prestigious history. This year there were sessions on large-scale sequencing and analysis, polymorphisms (covering discovery and technologies and mapping and analysis), comparative genomics of mammalian and model organism genomes, functional genomics and bioinformatics.

Download Full-text

Comparative Genomics Analysis of Streptomyces Species Reveals Their Adaptation to the Marine Environment and Their Diversity at the Genomic Level

Frontiers in Microbiology ◽

10.3389/fmicb.2016.00998 ◽

2016 ◽

Vol 7 ◽

Cited By ~ 19

Author(s):

Xinpeng Tian ◽

Zhewen Zhang ◽

Tingting Yang ◽

Meili Chen ◽

Jie Li ◽

...

Keyword(s):

Comparative Genomics ◽

Marine Environment ◽

Streptomyces Species ◽

Genomic Level ◽

Comparative Genomics Analysis

Download Full-text

Strategies to develop strain-specific PCR based assays for probiotics

Beneficial Microbes ◽

10.3920/bm2015.0009 ◽

2015 ◽

Vol 6 (6) ◽

pp. 887-898 ◽

Cited By ~ 8

Author(s):

P. Treven

Keyword(s):

Comparative Genomics ◽

Genome Sequencing ◽

Bacterial Genome ◽

Probiotic Strain ◽

Representational Difference Analysis ◽

Specific Marker ◽

Suppression Subtractive Hybridisation ◽

Specific Primers ◽

Specific Assay ◽

Specific Pcr

Since health benefits conferred by probiotics are strain-specific, identification to the strain level is mandatory to allow the monitoring of the presence and the abundance of specific probiotic in a product or in a gastrointestinal tract. Compared to standard plate counts, the reduced duration of the assays and higher specificity makes PCR-based methods (standard PCR and quantitative PCR) very appropriate for detection or quantification of probiotics. Development of strain-specific assay consists of 4 main stages: (1) strain-specific marker identification; (2) construction of potential strain-specific primers; (3) validation on DNA from pure cultures of target and related strains; and (4) validation on spiked samples. The most important and also the most challenging step is the identification of strain-specific sequences, which can be subsequently targeted by specific primers or probes. Such regions can be identified on sequences derived from 16S-23S internally transcribed spacers, randomly amplified polymorphic DNA, representational difference analysis and suppression subtractive hybridisation. Already known phenotypic or genotypic characteristics of the target strain can also be used to develop the strain-specific assay. However, the initial stage of strain-specific assay development can be replaced by comparative genomics analysis of target genome with related genomes in public databases. Advances in whole genome sequencing (WGS) have resulted in a cost reduction for bacterial genome sequencing and consequently have made this approach available to most laboratories. In the present paper I reviewed the available literature on PCR and qPCR assays developed for detection of a specific probiotic strain and discussed future WGS and comparative genomics-based approaches.

Download Full-text