scholarly journals Whole-Genome Sequencing of Corallococcus sp. Strain EGB Reveals the Genetic Determinants Linking Taxonomy and Predatory Behavior

Genes ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1421
Author(s):  
Yuqiang Zhao ◽  
Yanxin Wang ◽  
Chengyao Xia ◽  
Xu Li ◽  
Xianfeng Ye ◽  
...  
Keyword(s):  
Extracellular Enzymes ◽  
Genomic Analysis ◽  
Gene Clusters ◽  
Predatory Behavior ◽  
Phytopathogenic Fungi ◽  
Plant Diseases ◽  
Comparative Genomic ◽  
Comprehensive Overview ◽  
Circular Chromosome ◽  
Pan Genome

Corallococcus sp. strain EGB is a Gram-negative myxobacteria isolated from saline soil, and has considerable potential for the biocontrol of phytopathogenic fungi. However, the detailed mechanisms related to development and predatory behavior are unclear. To obtain a comprehensive overview of genetic features, the genome of strain EGB was sequenced, annotated, and compared with 10 other Corallococcus species. The strain EGB genome was assembled as a single circular chromosome of 9.4 Mb with 7916 coding genes. Phylogenomics analysis showed that strain EGB was most closely related to Corallococcus interemptor AB047A, and it was inferred to be a novel species within the Corallococcus genus. Comparative genomic analysis revealed that the pan-genome of Corallococcus genus was large and open. Only a small proportion of genes were specific to strain EGB, and most of them were annotated as hypothetical proteins. Subsequent analyses showed that strain EGB produced abundant extracellular enzymes such as chitinases and β-(1,3)-glucanases, and proteases to degrade the cell-wall components of phytopathogenic fungi. In addition, 35 biosynthetic gene clusters potentially coding for antimicrobial compounds were identified in the strain EGB, and the majority of them were present in the dispensable pan-genome with unexplored metabolites. Other genes related to secretion and regulation were also explored for strain EGB. This study opens new perspectives in the greater understanding of the predatory behavior of strain EGB, and facilitates a potential application in the biocontrol of fungal plant diseases in the future.

scholarly journals Insights into the cultured bacterial fraction of corals

2020 ◽  
Author(s):  
Michael Sweet ◽  
Helena Villela ◽  
Tina Keller-Costa ◽  
Rodrigo Costa ◽  
Stefano Romano ◽  
...  
Keyword(s):  
Genomic Analysis ◽  
Gene Clusters ◽  
Comparative Genomic ◽  
Rrna Gene ◽  
Comprehensive Overview ◽  
Associated Bacteria ◽  
Reef Restoration ◽  
Coral Holobiont ◽  
Metabolic Interactions ◽  
And Function

Abstract Bacteria associated with coral hosts are diverse and abundant, with recent studies suggesting involvement of these symbionts in host resilience to anthropogenic stress. Despite the putative importance of bacteria, the work dedicated to culturing coral-associated bacteria has received little attention. Combining published and unpublished data, here we report a comprehensive overview of the diversity and function of culturable, coral-associated bacteria. A total of 3055 isolates from 52 studies were considered by our meta-survey. Of these, 1045 had full length 16S rRNA gene sequences, spanning 138 formally described and 12 putatively novel bacterial genera across the Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria phyla. We performed comparative genomic analysis using the available genomes of 74 strains and identified potential signatures of beneficial bacterial-coral symbioses among them. Our analysis revealed >400 biosynthetic gene clusters that underlie the biosynthesis of antioxidant, antimicrobial, cytotoxic, and other secondary metabolites. Moreover, we uncovered genomic features - not previously described for coral-bacterial symbioses - involved in host colonization and host-symbiont recognition, antiviral defence mechanisms, and/or integrated metabolic interactions, which we suggest as novel targets for the screening of coral probiotics. Our results highlight the importance of bacterial cultures to elucidate coral holobiont functioning, and guide the selection of probiotic candidates to promote coral resilience and improve reef restoration efforts.

scholarly journals Categorization of Orthologous Gene Clusters in 92 Ascomycota Genomes Reveals Functions Important for Phytopathogenicity

2021 ◽  
Vol 7 (5) ◽  
pp. 337
Author(s):  
Daniel Peterson ◽  
Tang Li ◽  
Ana M. Calvo ◽  
Yanbin Yin
Keyword(s):  
Comparative Genomics ◽  
Orthologous Gene ◽  
Gene Clusters ◽  
Phytopathogenic Fungi ◽  
Secreted Proteins ◽  
Economic Losses ◽  
Comparative Genomic ◽  
Signal Peptides ◽  
Comparative Genomics Analysis

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.

scholarly journals Genome Reduction and Secondary Metabolism of the Marine Sponge-Associated Cyanobacterium Leptothoe

Marine Drugs ◽  
2021 ◽  
Vol 19 (6) ◽  
pp. 298
Author(s):  
Despoina Konstantinou ◽  
Rafael V. Popin ◽  
David P. Fewer ◽  
Kaarina Sivonen ◽  
Spyros Gkelis
Keyword(s):  
Natural Products ◽  
Microbial Communities ◽  
Genomic Analysis ◽  
Gene Clusters ◽  
Marine Sponges ◽  
Genome Reduction ◽  
Extracellular Polysaccharides ◽  
Comparative Genomic ◽  
Symbiotic Relationships ◽  
Genes Encoding

Sponges form symbiotic relationships with diverse and abundant microbial communities. Cyanobacteria are among the most important members of the microbial communities that are associated with sponges. Here, we performed a genus-wide comparative genomic analysis of the newly described marine benthic cyanobacterial genus Leptothoe (Synechococcales). We obtained draft genomes from Le. kymatousa TAU-MAC 1615 and Le. spongobia TAU-MAC 1115, isolated from marine sponges. We identified five additional Leptothoe genomes, host-associated or free-living, using a phylogenomic approach, and the comparison of all genomes showed that the sponge-associated strains display features of a symbiotic lifestyle. Le. kymatousa and Le. spongobia have undergone genome reduction; they harbored considerably fewer genes encoding for (i) cofactors, vitamins, prosthetic groups, pigments, proteins, and amino acid biosynthesis; (ii) DNA repair; (iii) antioxidant enzymes; and (iv) biosynthesis of capsular and extracellular polysaccharides. They have also lost several genes related to chemotaxis and motility. Eukaryotic-like proteins, such as ankyrin repeats, playing important roles in sponge-symbiont interactions, were identified in sponge-associated Leptothoe genomes. The sponge-associated Leptothoe stains harbored biosynthetic gene clusters encoding novel natural products despite genome reduction. Comparisons of the biosynthetic capacities of Leptothoe with chemically rich cyanobacteria revealed that Leptothoe is another promising marine cyanobacterium for the biosynthesis of novel natural products.

scholarly journals Comparative Analysis of Whole-Genome and Methylome Profiles of a Smooth and a Rough Mycobacterium abscessus Clinical Strain

2019 ◽  
Vol 10 (1) ◽  
pp. 13-22 ◽  
Author(s):  
Chiranjibi Chhotaray ◽  
Shuai Wang ◽  
Yaoju Tan ◽  
Amjad Ali ◽  
Muhammad Shehroz ◽  
...  
Keyword(s):  
Single Molecule ◽  
Gene Clusters ◽  
Mycobacterium Abscessus ◽  
Clinical Strain ◽  
Comparative Genomic ◽  
Illumina Hiseq ◽  
Clinical Strains ◽  
Synonymous Mutations ◽  
Pan Genome ◽  
Genome Wide

Mycobacterium abscessus is a fast growing Mycobacterium species mainly causing skin and respiratory infections in human. M. abscessus is resistant to numerous drugs, which is a major challenge for the treatment. In this study, we have sequenced the genomes of two clinical M. abscessus strains having rough and smooth morphology, using the single molecule real-time and Illumina HiSeq sequencing technology. In addition, we reported the first comparative methylome profiles of a rough and a smooth M. abscessus clinical strains. The number of N4-methylcytosine (4mC) and N6-methyladenine (6mA) modified bases obtained from smooth phenotype were two-fold and 1.6 fold respectively higher than that of rough phenotype. We have also identified 4 distinct novel motifs in two clinical strains and genes encoding antibiotic-modifying/targeting enzymes and genes associated with intracellular survivability having different methylation patterns. To our knowledge, this is the first report about genome-wide methylation profiles of M. abscessus strains and identification of a natural linear plasmid (15 kb) in this critical pathogen harboring methylated bases. The pan-genome analysis of 25 M. abscessus strains including two clinical strains revealed an open pan genome comprises of 7596 gene clusters. Likewise, structural variation analysis revealed that the genome of rough phenotype strain contains more insertions and deletions than the smooth phenotype and that of the reference strain. A total of 391 single nucleotide variations responsible for the non-synonymous mutations were detected in clinical strains compared to the reference genome. The comparative genomic analysis elucidates the genome plasticity in this emerging pathogen. Furthermore, the detection of genome-wide methylation profiles of M. abscessus clinical strains may provide insight into the significant role of DNA methylation in pathogenicity and drug resistance in this opportunistic pathogen.

scholarly journals Horizontal Gene Transfer Clarifies Taxonomic Confusion and Promotes the Genetic Diversity and Pathogenicity of Plesiomonas shigelloides

mSystems ◽  
2020 ◽  
Vol 5 (5) ◽  
Author(s):  
Zhiqiu Yin ◽  
Si Zhang ◽  
Yi Wei ◽  
Meng Wang ◽  
Shuangshuang Ma ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Evolutionary Dynamics ◽  
Genomic Analysis ◽  
Comparative Genomic ◽  
Content Type ◽  
Pan Genome ◽  
Long Time ◽  
Taxonomic Confusion

The taxonomic position of P. shigelloides has been the subject of debate for a long time, and until now, the evolutionary dynamics and pathogenesis of P. shigelloides were unclear. In this study, pan-genome analysis indicated extensive genetic diversity and the presence of large and variable gene repertoires. Our results revealed that horizontal gene transfer was the focal driving force for the genetic diversity of the P. shigelloides pan-genome and might have contributed to the emergence of novel properties. Vibrionaceae and Aeromonadaceae were found to be the predominant donor taxa for horizontal genes, which might have caused the taxonomic confusion historically. Comparative genomic analysis revealed the potential of P. shigelloides to cause intestinal and invasive diseases. Our results could advance the understanding of the evolution and pathogenesis of P. shigelloides, particularly in elucidating the role of horizontal gene transfer and investigating virulence-related elements.

scholarly journals High-quality genome assembly of the soybean fungal pathogen Cercospora kikuchii

2021 ◽  
Author(s):  
Takeshi Kashiwa ◽  
Tomohiro Suzuki
Keyword(s):  
Genome Assembly ◽  
Gene Prediction ◽  
Genomic Analysis ◽  
Agricultural Practices ◽  
Gene Clusters ◽  
Plant Diseases ◽  
Evolutionary Genomic ◽  
Soybean Leaf ◽  
Solid Foundation ◽  
Soybean Diseases

Abstract Plant diseases caused by the Cercospora genus of ascomycete fungi are a major concern for commercial agricultural practices. Several Cercospora species can affect soybeans, such as C. kikuchii which causes soybean leaf blight. Speciation in Cercospora on soybean has not been adequately studied. Some cryptic groups of Cercospora also cause diseases on soybean. Moreover, it has been known C. kikuchii population genetic structure is different between countries. Consequently, further genomic information could help to elucidate the covert differentiation of Cercospora diseases in soybean. Here, we report for the first time, a chromosome-level genome assembly for C. kikuchii. The genome assembly of 9 contigs was 34.44 Mb and the N50 was 4.19 Mb. Based on ab-initio gene prediction, several pathogenicity-related genes, including 242 genes for effector candidates, 55 secondary metabolite gene clusters, and 399 carbohydrate-active enzyme genes were identified. The genome sequence and the features described in this study provide a solid foundation for comparative and evolutionary genomic analysis for Cercospora species that cause soybean diseases worldwide.

scholarly journals Whole Genome Sequencing Based Taxonomic Classification, and Comparative Genomic Analysis of Potentially Human Pathogenic Enterobacter spp. Isolated from Chlorinated Wastewater in the North West Province, South Africa

2021 ◽  
Vol 9 (9) ◽  
pp. 1928
Author(s):  
Tawanda E. Maguvu ◽  
Cornelius C. Bezuidenhout
Keyword(s):  
Bacterial Species ◽  
Genomic Analysis ◽  
Gene Clusters ◽  
Comparative Genomic Analysis ◽  
Taxonomic Classification ◽  
Comparative Genomic ◽  
Whole Genome ◽  
Human Pathogens ◽  
Wastewater Treatment Process ◽  
North West

Comparative genomics, in particular, pan-genome analysis, provides an in-depth understanding of the genetic variability and dynamics of a bacterial species. Coupled with whole-genome-based taxonomic analysis, these approaches can help to provide comprehensive, detailed insights into a bacterial species. Here, we report whole-genome-based taxonomic classification and comparative genomic analysis of potential human pathogenic Enterobacter hormaechei subsp. hoffmannii isolated from chlorinated wastewater. Genome Blast Distance Phylogeny (GBDP), digital DNA-DNA hybridization (dDDH), and average nucleotide identity (ANI) confirmed the identity of the isolates. The algorithm PathogenFinder predicted the isolates to be human pathogens with a probability of greater than 0.78. The potential pathogenic nature of the isolates was supported by the presence of biosynthetic gene clusters (BGCs), aerobactin, and aryl polyenes (APEs), which are known to be associated with pathogenic/virulent strains. Moreover, analysis of the genome sequences of the isolates reflected the presence of an arsenal of virulence factors and antibiotic resistance genes that augment the predictions of the algorithm PathogenFinder. The study comprehensively elucidated the genomic features of pathogenic Enterobacter isolates from wastewaters, highlighting the role of wastewaters in the dissemination of pathogenic microbes, and the need for monitoring the effectiveness of the wastewater treatment process.

scholarly journals Pan-genome analyses of peach and its wild relatives provide insights into the genetics of disease resistance and species adaptation

2020 ◽  
Author(s):  
Ke Cao ◽  
Zhen Peng ◽  
Xing Zhao ◽  
Yong Li ◽  
Kuozhan Liu ◽  
...  
Keyword(s):  
High Altitude ◽  
Molecular Mechanisms ◽  
De Novo ◽  
Genomic Analysis ◽  
Gene Families ◽  
Wild Relatives ◽  
Comparative Genomic ◽  
High Altitude Adaptation ◽  
Pan Genome ◽  
Altitude Adaptation

AbstractAs a foundation to understand the molecular mechanisms of peach evolution and high-altitude adaptation, we performed de novo genome assembling of four wild relatives of P. persica, P. mira, P. kansuensis, P. davidiana and P. ferganensis. Through comparative genomic analysis, abundant genetic variations were identified in four wild species when compared to P. persica. Among them, a deletion, located at the promoter of Prupe.2G053600 in P. kansuensis, was validated to regulate the resistance to nematode. Next, a pan-genome was constructed which comprised 15,216 core gene families among four wild peaches and P. perisca. We identified the expanded and contracted gene families in different species and investigated their roles during peach evolution. Our results indicated that P. mira was the primitive ancestor of cultivated peach, and peach evolution was non-linear and a cross event might have occurred between P. mira and P. dulcis during the process. Combined with the selective sweeps identified using accessions of P. mira originating from different altitude regions, we proposed that nitrogen recovery was essential for high-altitude adaptation of P. mira through increasing its resistance to low temperature. The pan-genome constructed in our study provides a valuable resource for developing elite cultivars, studying the peach evolution, and characterizing the high-altitude adaptation in perennial crops.

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