Project description:Insights into the evolution of host association through the isolation and characterization of a human periodontal pathogen, Desulfobulbus oralis
Project description:Integrons are genetic elements that enable bacterial adaptation by collecting new genes encoded in integron cassettes (ICs) to create a reservoir of adaptive functions. These cassettes typically lack their own promoters and rely on the integron platform for their expression. Integrons, well-known for spreading antibiotic resistance genes in clinically relevant Gram-negative species, include Mobile Integrons (MIs), that transport over 170 resistance genes. In contrast, Sedentary Chromosomal Integrons (SCIs), ubiquitous in Vibrio species, are primarily found within bacterial chromosomes. However, their functions are not related to antimicrobial resistance and are largely unexplored. SCIs, typified by the Superintegron (SI) in Vibrio cholerae, represent ancient and highly variable regions in bacterial genomes. The SI is extensive, housing 179 integron cassettes, mostly with unknown functions. Although 19 cassettes encode toxin-antitoxin (TA) systems, which stabilize the array, the intricacies of the SI are challenging to study due to its size and unique integrase. To investigate the SI's impact on V. cholerae, we developed the SeqDelTA approach, enabling the gradual deletion of the SI. This deletion facilitates the use of standard genetic tools without SI interference. Our in-depth analysis of the resulting ∆SI strain, covering various aspects, demonstrated no significant alterations in V. cholerae's physiology. Despite their extended coevolution, SCIs appear to be genetically isolated from the host genome.
Project description:This SuperSeries is composed of the following subset Series: GSE32050: 5-hydroxymethylcytosine-mediated epigenetic dynamics during neurodevelopment and aging [5hmC Capture and Seq] GSE32187: 5-hydroxymethylcytosine-mediated epigenetic dynamics during neurodevelopment and aging [mRNA profiling] Refer to individual Series
Project description:We reported changes in RNA methylation levels in A549 cells caused by black phosphorus quantum dots and titanium dioxide nanoparticles.
Project description:In this study we investigate the transcriptomic response of Escherichia coli to CdTe-2.4 and benign CdSe-2.4 quantum dots, each with and without illumination to elucidate the phototherapeutic effect of CdTe-2.4. Our analysis sought to separate the transcriptomic responses of E. coli to the presence of superoxide and the presence of cadmium chalcogenide nanoparticles. We found eight genes to be consistently differentially expressed as a response to superoxide generation, and these genes demonstrate a consistent association with the DNA damage response and deactivation of iron-sulfur clusters, characteristic of a superoxide response. We found eighteen genes associated the presence of cadmium-based quantum dots, in isolation from the superoxide effect. In further analysis of these genes, we performed both amino acid supplementation and gene knockout experiments, identifying the importance of leucyl-tRNA downregulation as a cadmium-based QD response, as well as reinforcing the relationship between CdTe-2.4 stress and iron-sulfur clusters through the gene tusA. This study demonstrates the transcriptomic response of E. coli to CdTe-2.4 and CdSe-2.4 quantum dots and parses the different effects of superoxide versus material effects on the bacteria. Our findings may provide useful information towards the development of quantum dot-based antibacterial therapy in the future.
