Search results for "PLASMID"
showing 10 items of 327 documents
Analyse de la variabilité génétique mitochondriale et chloroplastique de deux espèces du genre Lupinus (L.Albus et L. Mutabilis)
1988
Notice présente dans BelInra (https://belinra.inra.fr/gestion/catalog.php?categ=isbd&id=90015); il s'agit d'un type de produit dont les métadonnées ne correspondent pas aux métadonnées attendues dans les autres types de produit : DISSERTATION; Analyse de la variabilité génétique mitochondriale et chloroplastique de deux espèces du genre Lupinus (L.Albus et L. Mutabilis)
The Sea Urchin sns Insulator Blocks CMV Enhancer following Integration in Human Cells
2001
Insulators are a new class of genetic elements that attenuate enhancer function directionally. Previously, we characterized in sea urchin a 265-bp-long insulator, termed sns. To test insulator activity following stable integration in human cells, we placed sns between the CMV enhancer and a tk promoter up-stream of a GFP transgene of plasmid or retroviral vectors. In contrast to controls, cells transfected or transduced with insulated constructs displayed a barely detectable fluorescence. Southern blot and PCR ruled out vector rearrangement following integration into host DNA; RNase protection confirmed the enhancer blocking activity. Finally, we demonstrate that two cis-acting sequences, p…
Simulating multilevel dynamics of antimicrobial resistance in a membrane computing model
2019
Membrane computing is a bio-inspired computing paradigm whose devices are the so-called membrane systems or P systems. The P system designed in this work reproduces complex biological landscapes in the computer world. It uses nested “membrane-surrounded entities” able to divide, propagate, and die; to be transferred into other membranes; to exchange informative material according to flexible rules; and to mutate and be selected by external agents. This allows the exploration of hierarchical interactive dynamics resulting from the probabilistic interaction of genes (phenotypes), clones, species, hosts, environments, and antibiotic challenges. Our model facilitates analysis of several aspects…
In vivo assembly of chromatin on pBR322 sequences cloned into yeast plasmids
1989
Abstract In order to study the in vivo assembly of chromatin on prokaryotic DNA templates, we have transformed yeast cells with plasmids pAJ50 and pRB58, which contain pBR322 sequences. In both cases nucleosomes are assembled in vivo on pBR322 DNA, although the nucleosomes are not homogeneous in size. To explore whether there is any preference for nucleosome assembly along pBR322 sequences, we have used an indirect end labeling method. The results indicate that most nucleosomes are placed at random on pBR322, although the probability for histone octamers to interact with some short regions is somewhat reduced. These regions coincide with sequences in which the frequency distribution of nucl…
Hybrid compounds generated by the introduction of a nogalamycin-producing plasmid into Streptomyces argillaceus
2003
The combination of genetic material from different antibiotic-producing organisms is a versatile and ever-expanding approach for the production of novel, hybrid compounds possessing bioactivity. The introduction of a plasmid (pSY21b) derived from Streptomyces nogalater and encoding PKS for nogalamycin production into the host strain S. argillaceus A43 led to the production of three new compounds in addition to the normally produced mithramycin. The new compounds are hybrids in the sense that they share features associated with the genes of both the host and the introduced plasmid. The structural elucidation of the novel compounds relied primarily on NMR spectroscopy, which revealed the thre…
Polymer Complexes in Biological Applications
2013
This chapter summarizes the influence of polyelectrolyte topology on biological functions and biomedical applications such as cell uptake, drug delivery, and gene transfection. Polyelectrolytes utilized are spherical structures derived from dendrimers and albumin or cylindrical brushes, all of which are decorated with various polypeptide chains.
Novel host-specific iron acquisition system in the zoonotic pathogenVibrio vulnificus
2015
Summary Vibrio vulnificus is a marine bacterium associated with human and fish (mainly farmed eels) diseases globally known as vibriosis. The ability to infect and overcome eel innate immunity relies on a virulence plasmid (pVvbt2) specific for biotype 2 (Bt2) strains. In the present study, we demonstrated that pVvbt2 encodes a host-specific iron acquisition system that depends on an outer membrane receptor for eel transferrin called Vep20. The inactivation of vep20 did not affect either bacterial growth in human plasma or virulence for mice, while bacterial growth in eel blood/plasma was abolished and virulence for eels was significantly impaired. Furthermore, vep20 is an iron-regulated ge…
Single- and Double-Strand Breaks of Dry DNA Exposed to Protons at Bragg-Peak Energies
2017
International audience; Ultrathin layers (<20 nm) of pBR322 plasmid DNA were deposited onto 2.5 μm thick polyester films and exposed to proton Bragg-peak energies (90–3000 keV) at various fluences. A quantitative analysis of radio-induced DNA damage is reported here in terms of single- and double-strand breaks (SSB and DSB, respectively). The corresponding yields as well as G-values and the cross sections exhibit fairly good agreement with the rare available data, stemming from close experimental conditions, namely, based on α particle irradiation. SSB/DSB rates appear to be linear when plotted against linear energy transfer (LET) in the whole energy range studied. All the data present a ma…
A common virulence plasmid in biotype 2 Vibrio vulnificus and its dissemination aided by a conjugal plasmid.
2007
ABSTRACT Strains of Vibrio vulnificus , a marine bacterial species pathogenic for humans and eels, are divided into three biotypes, and those virulent for eels are classified as biotype 2. All biotype 2 strains possess one or more plasmids, which have been shown to harbor the biotype 2-specific DNA sequences. In this study we determined the DNA sequences of three biotype 2 plasmids: pR99 (68.4 kbp) in strain CECT4999 and pC4602-1 (56.6 kb) and pC4602-2 (66.9 kb) in strain CECT4602. Plasmid pC4602-2 showed 92% sequence identity with pR99. Curing of pR99 from strain CECT4999 resulted in loss of resistance to eel serum and virulence for eels but had no effect on the virulence for mice, an anim…
Midbiotics : conjugative plasmids for genetic engineering of natural gut flora
2019
ABSTRACTThe possibility to modify gut bacterial flora has become an important goal, and various approaches are used to achieve desirable communities. However, the genetic engineering of existing microbes in the gut, which are already compatible with the rest of the community and host immune system, has not received much attention. Here, we discuss and experimentally evaluate the possibility to use modified and mobilizable CRISPR-Cas9-endocing plasmid as a tool to induce changes in bacterial communities. This plasmid system (briefly midbiotic) is delivered from bacterial vector into target bacteria via conjugation. Compared to, for example, bacteriophage-based applications, the benefits of c…