Phylogenetic Analysis of Pseudomonas syringae Pathovars Suggests the Horizontal Gene Transfer of argK and the Evolutionary Stability of hrp Gene Cluster

1999 ◽  
Vol 49 (5) ◽  
pp. 627-644 ◽  
Author(s):  
Hiroyuki Sawada ◽  
Fumihiko Suzuki ◽  
Izumi Matsuda ◽  
Naruya Saitou
Keyword(s):  
Phylogenetic Analysis ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Gene Cluster ◽  
Pseudomonas Syringae ◽  
Evolutionary Stability ◽  
Pseudomonas Syringae Pathovars

scholarly journals Genetic Organization of the Pantoea stewartii subsp. stewartii hrp Gene Cluster and Sequence Analysis of the hrpA, hrpC, hrpN, and wtsE Operons

2001 ◽  
Vol 14 (10) ◽  
pp. 1213-1222 ◽  
Author(s):  
Reid D. Frederick ◽  
Musharaf Ahmad ◽  
Doris R. Majerczak ◽  
Angel S. Arroyo-Rodríguez ◽  
Shulamit Manulis ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Pseudomonas Syringae ◽  
Sweet Corn ◽  
Open Reading Frames ◽  
Nucleotide Sequencing ◽  
Promoter Sequences ◽  
Pantoea Stewartii ◽  
Regulatory Mutations ◽  
Complementation Groups ◽  
Pseudomonas Syringae Pathovars

The hrp/wts gene cluster of Pantoea stewartii subsp. stewartii is required for pathogenicity on sweet corn and the ability to elicit a hypersensitive response (HR) in tobacco. Site-directed transposon mutagenesis and nucleotide sequencing were used to identify hrp/wts genes within the left 20 kb of this cluster. Seventeen open reading frames (ORFs) comprise seven genetic complementation groups. These ORFs share homology with hrp and dsp genes from Erwinia amylovora, Erwinia chrysanthemi, and Pseudomonas syringae pathovars and have been designated, in map order, wtsF, wtsE, hrpN, hrpV, hrpT, hrcC, hrpG, hrpF, hrpE, hrpD, hrcJ, hrpB, hrpA, hrpS, hrpY, hrpX, and hrpL. Putative hrp consensus promoter sequences were identified upstream of hrpA, hrpF, hrpN, and wtsE. Expression of the hrpA, hrpC, and wtsE operons was regulated by HrpS. Transposon mutations in all of the hrp operons abolished pathogenicity and HR elicitation, except for the hrpN and hrpV mutants, which were still pathogenic. hrpS, hrpXY, and hrpL regulatory mutations abolished HrpN synthesis, whereas secretory mutations in the hrpC, hrpA, and hrpJ operons permitted intracellular HrpN synthesis. wtsEF mutants were not pathogenic but still produced HrpN and elicited the HR. wtsE encodes a 201-kDa protein that is similar to DspE in E. amylovora and AvrE in P. syringae pv. tomato, suggesting that this protein is a major virulence factor involved in the elicitation of water-soaked lesions.

scholarly journals Novel 4-Chlorophenol Degradation Gene Cluster and Degradation Route via Hydroxyquinol in Arthrobacter chlorophenolicus A6

2005 ◽  
Vol 71 (11) ◽  
pp. 6538-6544 ◽  
Author(s):  
Karolina Nordin ◽  
Maria Unell ◽  
Janet K. Jansson
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Gene Cluster ◽  
Microbial Degradation ◽  
Codon Bias ◽  
Sequence Similarity ◽  
Open Reading Frames ◽  
Genes Encoding ◽  
Arthrobacter Chlorophenolicus ◽  
Reading Frames

ABSTRACT Arthrobacter chlorophenolicus A6, a previously described 4-chlorophenol-degrading strain, was found to degrade 4-chlorophenol via hydroxyquinol, which is a novel route for aerobic microbial degradation of this compound. In addition, 10 open reading frames exhibiting sequence similarity to genes encoding enzymes involved in chlorophenol degradation were cloned and designated part of a chlorophenol degradation gene cluster (cph genes). Several of the open reading frames appeared to encode enzymes with similar functions; these open reading frames included two genes, cphA-I and cphA-II, which were shown to encode functional hydroxyquinol 1,2-dioxygenases. Disruption of the cphA-I gene yielded a mutant that exhibited negligible growth on 4-chlorophenol, thereby linking the cph gene cluster to functional catabolism of 4-chlorophenol in A. chlorophenolicus A6. The presence of a resolvase pseudogene in the cph gene cluster together with analyses of the G+C content and codon bias of flanking genes suggested that horizontal gene transfer was involved in assembly of the gene cluster during evolution of the ability of the strain to grow on 4-chlorophenol.

scholarly journals Adaptation by Ancient Horizontal Acquisition of Butyrate Metabolism Genes in Aggregatibacter actinomycetemcomitans

mBio ◽  
2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Ahmed M. Moustafa ◽  
Senthil Kumar Velusamy ◽  
Lidiya Denu ◽  
Apurva Narechania ◽  
Daniel H. Fine ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Strong Association ◽  
Aggregatibacter Actinomycetemcomitans ◽  
Short Chain ◽  
Oral Microbiota ◽  
Content Type ◽  
History Of ◽  
The Impact

ABSTRACT Like the bacterial residents of the human gut, it is likely that many of the species in the human oral microbiota have evolved to better occupy and persist in their niche. Aggregatibacter actinomycetemcomitans (Aa) is both a common colonizer of the oral cavity and has been implicated in the pathogenesis of periodontal disease. Here, we present a whole-genome phylogenetic analysis of Aa isolates from humans and nonhuman primates that revealed an ancient origin for this species and a long history of association with the Catarrhini, the lineage that includes Old World monkeys (OWM) and humans. Further genomic analysis showed a strong association with the presence of a short-chain fatty acid (SCFA) catabolism locus (atoRDAEB) in many human isolates that was absent in almost all nonhuman OWM isolates. We show that this locus was likely acquired through horizontal gene transfer. When grown under conditions that are similar to those at the subgingival site of periodontitis (anaerobic, SCFA replete), Aa strains with atoRDAEB formed robust biofilms and showed upregulation of genes involved in virulence, colonization, and immune evasion. Both an isogenic deletion mutant and nonhuman primate isolates lacking the ato locus failed to grow in a robust biofilm under these conditions, but grew well under the carbohydrate-rich conditions similar to those found above the gumline. We propose that the acquisition of the ato locus was a key evolutionary step allowing Aa to utilize SCFAs, adapt, and modulate subgingival disease. IMPORTANCE There has been considerable interest in the impact of short-chain fatty acids (SCFAs) on inflammatory effects related to the microbiome. Here, we present evidence that SCFAs may also be important in disease by providing an energy source or disease-associated cue for colonizing pathogens. We propose that SCFAs allow Aggregatibacter actinomycetemcomitans (Aa) to adapt to the subgingival anaerobic environment, which is the site of human periodontitis. Under anaerobic, SCFA-rich conditions, human-derived Aa strains that possess butyrate metabolism genes form strong biofilms and upregulate virulence genes. Our phylogenetic analysis highlights a long history of evolution of Aa with its primate hosts and suggests that the acquisition of butyrate metabolism genes may have been a critical step in allowing Aa to colonize a new niche and cause disease in humans. Overall, this study highlights the important role that horizontal gene transfer may play in microbial adaptation and the evolution of infectious disease.

scholarly journals Genomic features and evolution of the conditionally dispensable chromosome in the tangerine pathotype of Alternaria alternata

2017 ◽  
Author(s):  
Mingshuang Wang ◽  
Huilan Fu ◽  
Xing-Xing Shen ◽  
Ruoxin Ruan ◽  
Nicholas Pun ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Gene Cluster ◽  
Alternaria Alternata ◽  
Deletion Mutant ◽  
Metabolic Process ◽  
Brown Spot ◽  
P Value ◽  
Dispensable Chromosome ◽  
Cdc Genes

AbstractThe tangerine pathotype of the ascomycete fungus Alternaria alternata is the causal agent of citrus brown spot, which can result in significant losses of both yield and marketability for tangerines and tangerine hybrids worldwide. A conditionally dispensable chromosome (CDC), which harbors the host-selective ACT toxin gene cluster, is required for tangerine pathogenicity of A. alternata. To understand the genetic makeup and evolution of the tangerine pathotype CDC, we analyzed the function and evolution of the CDC genes present in the A. alternata Z7 strain. The 1.84Mb long CDC contains 512 predicted protein-coding genes, which are enriched in functional categories associated with ‘metabolic process’ (132 genes, p-value = 0.00192) including ‘oxidation-reduction process’ (48 genes, p-value = 0.00021) and ‘lipid metabolic process’ (11 genes, p-value = 0.04591). Relatively few of the CDC genes can be classified as CAZymes (13), kinases (3) and transporters (20). Differential transcriptome analysis of H2O2 treatment and control conditions revealed that 29 CDC genes were significantly up-regulated and 14 were significantly down-regulated, suggesting that CDC genes may play a role in coping with oxidative stress. Evolutionary analysis of the 512 CDC proteins showed that their evolutionary conservation tends to be restricted within the genus Alternaria and that the CDC genes evolve faster than genes in the essential chromosomes. Interestingly, phylogenetic analysis suggested that the genes of 13 enzymes and one sugar transporter residing in the CDC were likely horizontally transferred from distantly related species. Among these, one carboxylesterase gene was transferred from bacteria but functionally knocking out this gene revealed no obvious biological role. Another 4 genes might have been transferred from Colletotrichum (Sordariomycetes) and 5 were likely transferred as a physically linked cluster of genes from Cryptococcus (Basidiomycota) or Penicillium (Eurotiomycetes). Functionally knocking out the 5-gene cluster resulted in an 80% decrease in asexual spore production in the deletion mutant. These results provide new insights into the function and evolution of CDC genes in Alternaria.Author SummaryMany fungal phytopathogens harbor conditionally dispensable chromosomes (CDCs). CDCs are variable in size, contain many genes involved in virulence, but their evolution remains obscure. In this study, we investigated the origin of the CDC present in the tangerine pathotype of Alternaria alternata Z7 strain. We found that most of the Z7 CDC proteins are highly conserved within the genus Alternaria but poorly conserved outside the genus. We also discovered that a small number of genes originated via horizontal gene transfer (HGT) from distantly related fungi and bacteria. These horizontally transferred genes include a carboxylesterase gene that was likely acquired from bacteria, a cluster of 4 physically linked genes likely transferred from Colletotrichum, and a cluster of 5 physically linked genes likely transferred from Cryptococcus (Basidiomycota) or Penicillium (Eurotiomycetes). To gain insight into the functions of these transferred genes, we knocked out the bacterial carboxylesterase and the 5-gene cluster. Whereas the carboxylesterase deletion mutant showed no obvious phenotype, the 5-gene cluster mutant showed a dramatically reduced production of asexual spores (conidia). The results of our study suggest that Alternaria CDCs are largely comprised from rapidly evolving native genes; although only a few genes were acquired via horizontal gene transfer, some of them appear to be involved in functions critical to the phytopathogenic lifestyle.

scholarly journals Phylogenetic analysis of genomic islands in closely-related species belonging to Sinorhizobium sp.

2020 ◽  
Author(s):  
M. E. Vladimirova ◽  
V. S. Muntyan ◽  
A. S. Saksaganskaya ◽  
B. V. Simarov ◽  
M. L. Roumiantseva
Keyword(s):  
Phylogenetic Analysis ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Related Species ◽  
Genomic Islands ◽  
Closely Related Species ◽  
Homologous Sequences

Genomic islands of closely related S. meliloti and S. medicae species were evaluated and homologous sequences were identified; it has been suggested that horizontal gene transfer occurs at homologous tRNA sites.

scholarly journals A comprehensive phylogenetic analysis of the serpin superfamily

2020 ◽  
Author(s):  
Matthew A. Spence ◽  
Matthew D. Mortimer ◽  
Ashley M. Buckle ◽  
Bui Quang Minh ◽  
Colin J. Jackson
Keyword(s):  
Phylogenetic Analysis ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Convergent Evolution ◽  
Alternative Hypothesis ◽  
Structural Alignment ◽  
High Homology ◽  
Physiological Processes ◽  
New Directions ◽  
Hub Proteins

Serine protease inhibitors (serpins) are found in all kingdoms of life and play essential roles in multiple physiological processes. Owing to the diversity of the superfamily, phylogenetic analysis is challenging and prokaryotic serpins have been speculated to have been acquired from Metazoa through horizontal gene transfer (HGT) due to their unexpectedly high homology. Here we have leveraged a structural alignment of diverse serpins to generate a comprehensive 6000-sequence phylogeny that encompasses serpins from all kingdoms of life. We show that in addition to a central “hub” of highly conserved serpins, there has been extensive diversification of the superfamily into many novel functional clades. Our analysis indicates that the hub proteins are ancient and are similar because of convergent evolution, rather than the alternative hypothesis of HGT. This work clarifies longstanding questions in the evolution of serpins and provides new directions for research in the field of serpin biology.

scholarly journals Diversity of MSDIN family members in amanitin-producing mushrooms and the phylogeny of the MSDIN and prolyl oligopeptidase genes

2020 ◽  
Author(s):  
Zhengmi He ◽  
Pan Long ◽  
Fang Fang ◽  
Sainan Li ◽  
Ping Zhang ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Gene Transfer ◽  
North America ◽  
Horizontal Gene Transfer ◽  
Transcriptome Analysis ◽  
Transcriptome Sequencing ◽  
Taxonomic Status ◽  
Chemical Substance ◽  
Prolyl Oligopeptidase ◽  
Pcr Cloning

Abstract Background: Amanitin-producing mushrooms, mainly distributed in the genera Amanita , Galerina and Lepiota , possess MSDIN gene family for the biosynthesis of many cyclopeptides catalysed by prolyl oligopeptidase (POP). Recently, transcriptome sequencing has proven to be an efficient way to mine MSDIN and POP genes in these lethal mushrooms. Thus far, only A . palloides and A. bisporigera from North America and A . exitialis and A. rimosa from Asia have been studied based on transcriptome analysis. However, the MSDIN and POP genes of many amanitin-producing mushrooms in China remain unstudied; hence, the transcriptomes of these speices deserve to be analysed. Results: In this study, the MSDIN and POP genes from ten Amanita species, two Galerina species and Lepiota venenata were studied and the phylogenetic relationships of their MSDIN and POP genes were analysed. Through transcriptome sequencing and PCR cloning, 19 POP genes and 151 MSDIN gened to encode 98 non-duplicated cyclopeptides, including α- amanitin, β-amanitin, phallacidin, phalloidin and 94 unknown peptides, were found in these species. Phylogenetic analysis showed that (1) MSDIN genes generally clustered depending on the taxonomy of the genus, while Amanita MSDIN genes clustered depending on the chemical substance; and (2) the POPA genes of Amanita , Galerina and Lepiota clustered and were separated into three different groups, but the POPB genes of the three distinct genera were clustered in a highly supported monophyletic group. Conclusions: These results indicate that lethal Amanita species have the genetic capacity to produce numerous cyclopeptides, most of which are unknown, while lethal Galerina and Lepiota species seem to only have the genetic capacity to produce α-amanitin. Additionally, the POPB phylogeny of Amanita , Galerina and Lepiota conflicts with the taxonomic status of the three genera, suggesting that underlying horizontal gene transfer has occurred among these three genera.

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