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

Author(s):  
M. E. Vladimirova ◽  
V. S. Muntyan ◽  
A. S. Saksaganskaya ◽  
B. V. Simarov ◽  
M. L. Roumiantseva

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.

2020 ◽  
Vol 36 (Supplement_2) ◽  
pp. i651-i658 ◽  
Author(s):  
Adelme Bazin ◽  
Guillaume Gautreau ◽  
Claudine Médigue ◽  
David Vallenet ◽  
Alexandra Calteau

Abstract Motivation Horizontal gene transfer (HGT) is a major source of variability in prokaryotic genomes. Regions of genome plasticity (RGPs) are clusters of genes located in highly variable genomic regions. Most of them arise from HGT and correspond to genomic islands (GIs). The study of those regions at the species level has become increasingly difficult with the data deluge of genomes. To date, no methods are available to identify GIs using hundreds of genomes to explore their diversity. Results We present here the panRGP method that predicts RGPs using pangenome graphs made of all available genomes for a given species. It allows the study of thousands of genomes in order to access the diversity of RGPs and to predict spots of insertions. It gave the best predictions when benchmarked along other GI detection tools against a reference dataset. In addition, we illustrated its use on metagenome assembled genomes by redefining the borders of the leuX tRNA hotspot, a well-studied spot of insertion in Escherichia coli. panRPG is a scalable and reliable tool to predict GIs and spots making it an ideal approach for large comparative studies. Availability and implementation The methods presented in the current work are available through the following software: https://github.com/labgem/PPanGGOLiN. Detailed results and scripts to compute the benchmark metrics are available at https://github.com/axbazin/panrgp_supdata.


Zootaxa ◽  
2017 ◽  
Vol 4320 (3) ◽  
pp. 505 ◽  
Author(s):  
ROMANA KALOUSOVA ◽  
LADISLAV BOCAK

Cladophorus Guérin-Méneville, 1830 are endemic Papuan net-winged beetles which take part in highly diverse Müllerian mimicry rings. Available specimens were sequenced for cox1–tRNA-Leu–cox2 mitochondrial DNA fragment and the species delimitations were based on the genetic distance, phylogenetic analysis, and morphology. Three earlier described species were identified in the recently collected material and further 10 species are described: C. pallescens sp. nov., C. bicolor sp. nov., C. craterensis sp. nov., C. motykai sp. nov., C. mindikensis sp. nov., C. kailakiensis sp. nov., C. manokwarensis sp. nov., C. haiaensis sp. nov., C. humeralis sp. nov., and C. boceki sp. nov. DNA-based identifications provided some ambiguous results and closely related species could not be robustly delimited using solely molecular data. Additionally, the species limits were based on clearly defined morphological characters and the morphological differentiation was found unlinked from the genetic divergence. Colour patterns cannot be used for identification because all species available in more specimens were polymorphic and followed various local co-mimics. The Papuan fauna of Cladophorus is very diverse and the closely related species regularly occur in limited regions. Differentiation within restricted ranges is therefore considered as the main speciation mode. 


Genes ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 569 ◽  
Author(s):  
Phale ◽  
Shah ◽  
Malhotra

In the biosphere, the largest biological laboratory, increased anthropogenic activities have led microbes to evolve and adapt to the changes occurring in the environment. Compounds, specifically xenobiotics, released due to such activities persist in nature and undergo bio-magnification in the food web. Some of these compounds act as potent endocrine disrupters, mutagens or carcinogens, and therefore their removal from the environment is essential. Due to their persistence, microbial communities have evolved to metabolize them partially or completely. Diverse biochemical pathways have evolved or been assembled by exchange of genetic material (horizontal gene transfer) through various mobile genetic elements like conjugative and non-conjugative plasmids, transposons, phages and prophages, genomic islands and integrative conjugative elements. These elements provide an unlimited opportunity for genetic material to be exchanged across various genera, thus accelerating the evolution of a new xenobiotic degrading phenotype. In this article, we illustrate examples of the assembly of metabolic pathways involved in the degradation of naphthalene and its derivative, Carbaryl, which are speculated to have evolved or adapted through the above-mentioned processes.


2009 ◽  
Vol 33 (2) ◽  
pp. 376-393 ◽  
Author(s):  
Mario Juhas ◽  
Jan Roelof van der Meer ◽  
Muriel Gaillard ◽  
Rosalind M. Harding ◽  
Derek W. Hood ◽  
...  

2005 ◽  
Vol 71 (6) ◽  
pp. 3126-3130 ◽  
Author(s):  
Ren Zhang ◽  
Chun-Ting Zhang

ABSTRACT Corynebacterium efficiens is a gram-positive nonpathogenic bacterium which can grow and produce glutamate at 40°C or above. By using the cumulative GC profile method, we have identified four genomic islands which have many unifying genomic island-specific features in the C. efficiens genome. The presence of the gene encoding an aspartate kinase in a genomic island helps explain the unexpected low thermal stability of this enzyme; i.e., the adaptive mutations have not occurred extensively due to the recent horizontal gene transfer.


2014 ◽  
Vol 46 (1) ◽  
pp. 25-37 ◽  
Author(s):  
Alan M. FRYDAY ◽  
Christian PRINTZEN ◽  
Stefan EKMAN

AbstractThe new generic name Bryobilimbia is proposed for Lecidea hypnorum and the closely related taxa Lecidea ahlesii var. ahlesii, L. ahlesii var. nemoralis, L. diapensiae, L. sanguineoatra and Mycobilimbia australis. A phylogenetic analysis based on five genes shows that Lecidea berengeriana does not belong to this group but is more closely related to Romjularia. Both groups of species have been included in Mycobilimbia by some authors but are instead shown to be most closely related to a group of genera (including Clauzadea, Farnoldia, Lecidoma and Romjularia) that do not belong to Lecideaceae s. str. A neotype is selected for Lichen sanguineoater Wulfen and the new combinations Bryobilimbia ahlesii var. ahlesii, B. ahlesii var. nemoralis, B. australis, B. diapensiae, B. hypnorum and B. sanguineoatra are proposed. A lectotype is also selected for L. templetonii Taylor.


mBio ◽  
2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Ahmed M. Moustafa ◽  
Senthil Kumar Velusamy ◽  
Lidiya Denu ◽  
Apurva Narechania ◽  
Daniel H. Fine ◽  
...  

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.


2020 ◽  
Author(s):  
Kakeru Yokoi ◽  
Kiyoshi Kimura ◽  
Hidemasa Bono

AbstractBackgroundMariner and mariner-like elements (MLEs) are distributed in various species and their sequences are highly diverse. In previous reports, a few transposable element in the genomes of Apis species mainly consist of mariner and MLE. For further insight of Apis MLEs, detailed classifications of Apis MLE and sequences analysis of long MLEs, which may potentially encode the transposase, are needed.ResultsMuch more MLEs were detected in A. mellifera genome compared to other Apis species genomes. They were classified into 31 Drosophila MLE classes. In this classification, almost all of MLEs were classified into the three classes belonging to mellifera subfamilies, suggesting that Apis MLEs which exist thorough Apis species derived from single MLE belonging to mellifera subfamily. Phylogenetic analysis using MLEs in the three classes showed that there two types of clusters, of which one consist of multiple Apis species MLEs, and others of only A. mellifera MLEs. Long MLEs analysis showed that only one long MLE encoding complete transposase was found in all Apis genome except for A. mellifera genome, and the MLE and multiple MLEs similar to it were found in A. mellifera genome. The analysis also showed that other several long MLEs encoding complete transposase were found only in A. mellifera genome.ConclusionsAlmost all of Apis MLEs are mellifera subfamilies. Of these MLEs, one types of them settled in Apis species and burst in A. mellifera genome. The other one of MLEs invaded into A. mellifera genome by horizontal transfer and exploded in A. mellifera genome. This is the first example of the finer aspects of MLE evolution among closely related species.


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