Search results for "Mobile genetic elements"

Ocean acidification at a coastal CO2 vent induces expression of stress-related transcripts and transposable elements in the sea anemone Anemonia viri…

2019

Published version, available at: https://doi.org/10.1371/journal.pone.0210358 Ocean acidification threatens to disrupt interactions between organisms throughout marine ecosystems. The diversity of reef-building organisms decreases as seawater CO2 increases along natural gradients, yet soft-bodied animals, such as sea anemones, are often resilient. We sequenced the polyA-enriched transcriptome of adult sea anemone Anemonia viridis and its dinoflagellate symbiont sampled along a natural CO2 gradient in Italy to assess stress levels in these organisms. We found that about 1.4% of the anemone transcripts, but only ~0.5% of the Symbiodinium sp. transcripts were differentially expressed. Processe…

The gypsy database (GyDB) of mobile genetic elements: release 2.0

2011

This article introduces the second release of the Gypsy Database of Mobile Genetic Elements (GyDB 2.0): a research project devoted to the evolutionary dynamics of viruses and transposable elements based on their phylogenetic classification (per lineage and protein domain). The Gypsy Database (GyDB) is a long-term project that is continuously progressing, and that owing to the high molecular diversity of mobile elements requires to be completed in several stages. GyDB 2.0 has been powered with a wiki to allow other researchers participate in the project. The current database stage and scope are long terminal repeats (LTR) retroelements and relatives. GyDB 2.0 is an update based on the analys…

2018

Mobile genetic elements such as conjugative plasmids are responsible for antibiotic resistance phenotypes in many bacterial pathogens. The ability to conjugate, the presence of antibiotics, and ecological interactions all have a notable role in the persistence of plasmids in bacterial populations. Here, we set out to investigate the contribution of these factors when the conjugation network was disturbed by a plasmid-dependent bacteriophage. Phage alone effectively caused the population to lose plasmids, thus rendering them susceptible to antibiotics. Leakiness of the antibiotic resistance mechanism allowing Black Queen evolution (i.e. a "race to the bottom") was a more significant factor t…

Simulation-based estimation of branching models for LTR retrotransposons

2017

Abstract Motivation LTR retrotransposons are mobile elements that are able, like retroviruses, to copy and move inside eukaryotic genomes. In the present work, we propose a branching model for studying the propagation of LTR retrotransposons in these genomes. This model allows us to take into account both the positions and the degradation level of LTR retrotransposons copies. In our model, the duplication rate is also allowed to vary with the degradation level. Results Various functions have been implemented in order to simulate their spread and visualization tools are proposed. Based on these simulation tools, we have developed a first method to evaluate the parameters of this propagation …

TarSynFlow, a workflow for bacterial genome comparisons that revealed genes putatively involved in the probiotic character of Shewanella putrefaciens…

2019

Probiotic microorganisms are of great interest in clinical, livestock and aquaculture. Knowledge of the genomic basis of probiotic characteristics can be a useful tool to understand why some strains can be pathogenic while others are probiotic in the same species. An automatized workflow called TarSynFlow (Targeted Synteny Workflow) has been then developed to compare finished or draft bacterial genomes based on a set of proteins. When used to analyze the finished genome of the probiotic strain Pdp11 ofShewanella putrefaciensand genome drafts from seven known non-probiotic strains of the same species obtained in this work, 15 genes were found exclusive of Pdp11. Their presence was confirmed …

Virulence-Associated Mobile Elements in Bacilli and Clostridia

2014

This chapter focuses on (i) species that induce human diseases, (ii) species that are able to produce toxins, and (iii) the association of appropriate virulence factors with possible mobile elements. With reference to bacilli, the chapter discusses mainly Bacillus anthracis and B. cereus. A section on clostridia focuses on Clostridium perfringens, neurotoxin-producing clostridia, and species capable of producing large clostridial cytotoxins (LCTs). The chapter talks about the contribution of the genetic mobility of virulence genes to the evolution of pathogenic bacilli and clostridia. B. anthracis strains produce a tripartite protein toxin, comprising PA (protective antigen), EF (edema fact…

Definition of the single integration site of the pathogenicity locus in Clostridium difficile.

1996

We determined the nucleotide sequence 3.8 kb upstream and 5.2 kb downstream of the toxin genes A and B of Clostridium difficile. Nine ORFs were discovered. Based on PCR-directed approaches, two were attributed to the pathogenicity locus (PaLoc). The other seven were found in every C. difficile isolate obtained from the human gastrointestinal tract, respectless of their toxinogenicity. The ORFs cdu1 and cdu2/2' upstream of the PaLoc displayed similarity to repressors of Gram-positive bacteria (cdu1), and to an Na+/H+ antiporter described for Enterococcus hirae (cdu2/2'). Downstream of the locus a putative ABC transporter (cdd2-4) was identified. With a set of three paired primers used in pol…

Impact of Insertion Sequences and RNAs on Genomic Inversions in Pseudomonas aeruginosa

2022

Abstract In this article, a bioinformatics pipeline is proposed that focuses on two types of elements, namely the mobile genetic elements (MGE) and Ribonucleic acids (RNAs). The MGEs are called insertion sequences (ISs) in the prokaryotic domain. The objective of this research work is to study the behaviour of RNAs and MGEs genes, and the effects of their presence around inversions in genome sequences. The proposed pipeline finds the relation between the transposase gene types (e.g., DDE and DEDD) located within insertion sequences according to their IS family and sub-family, and RNAs (tRNA and rRNA) on the one hand, and genomic inversion on the other hand. More precisely, we wonder whether…

PCR Typing of Alu Elements — Molecular Genetics and Forensic Application

1996

Alu repeats belong to the family of short interspersed elements (SINEs) and are among the most abundant repetitive DNA sequences in the mammalian genome. They represent mobile genetic elements ancestrally derived from the 7SL RNA gene and have presumably spread within the genome by retroposition (reviewed in [1]). A particular group of Alu repeats appears to be human-specific (HS subfamily) and has expanded only recently within the human genome as indicated by distinct dimorphisms at various loci due to the presence or absence of an Alu repeat. In recent extensive studies, the frequency distributions of Alu insertions at selected loci in various human racial groups and populations were dete…

Classification of prokaryotic genetic replicators: between selfishness and altruism

2015

Prokaryotes harbor a variety of genetic replicators, including plasmids, viruses, and chromosomes, each having different effects on the phenotype of the hosting cell. Here, we propose a classification for replicators of bacteria and archaea on the basis of their horizontal-transfer potential and the type of relationships (mutualistic, symbiotic, commensal, or parasitic) that they have with the host cell vehicle. Horizontal movement of replicators can be either active or passive, reflecting whether or not the replicator encodes the means to mediate its own transfer from one cell to another. Some replicators also have an infectious extracellular state, thus separating viruses from other mobil…