Project description:The maltose regulon (mal regulon) has previously been shown to consist of the mal gene cluster (malQP, malXCD and malAR operons) in Streptococcus pneumoniae. In this study, we have further elucidated the complete mal regulon in S. pneumoniae D39 using microarray analyses and β-galactosidase assays. In addition to the mal gene cluster, the complete mal regulon of S. pneumoniae D39 consists of a pullulanase (PulA), a glucosidase (DexB), a glucokinase (RokB), a PTS component (PtsG) and an amylase (AmyA2). Our microarray studies and β-galactosidase assays further showed that the LacI-family transcriptional regulator MalR represses the expression of the mal regulon in the absence of maltose. Furthermore, the role of the pleiotropic transcriptional regulator CcpA in the regulation of the mal regulon in the presence of maltose was also explored. Our microarray analysis with a ΔccpA strain showed that CcpA only represses the expression of the malXCD operon and the pulA gene in the presence of maltose. This SuperSeries is composed of the SubSeries listed below.
Project description:Hexavalent chromium (Cr(VI)) is a highly toxic contaminant, some bacteria are able to transform it to less toxic and less soluble trivalent chromium (Cr(III)). Klebsiella sp. strain AqSCr, isolated from Cr(VI)-polluted groundwater, reduces Cr(VI) both aerobically and anaerobically, and resists up 35 mM of Cr(VI); Subculturing of AqSCr in the presence of Cr(VI) conduces to adaptation. In this study, we performed RNA-Seq of Cr(VI) adapted stage, finding 255 genes upregulated and 240 downregulated with respect to controls without Cr(VI). Genes differentially expressed are mostly associated with oxidative stress response, DNA repair and replication, sulfur starvation response, envelope-osmotic stress response, fatty acid metabolism, ribosomal subunits and energy metabolism. Among them, genes not previously associated with chromium resistance as cybB, encoding a putative superoxide oxidase, gltA2, encoding an alternative citrate synthase, and des, encoding a fatty acid desaturase were upregulated. The alternative sigma factors fecl, rpoE and rpoS were upredgulated in Cr(VI) adapted cells, then they participate in orchestate the Cr(VI)-resistance mechanisms in AqSCr strain
Project description:MLS000408882-01 and MLS000573813-01 were identified through a cell based screen that measures the reactivation of an epigenetically silenced transgene. MLS000408882-01 and MLS000573813-01 shows selectivity for cancer vs. normal cells affecting both transcriptional patterns and cell viability in a cancer specific manner.
Project description:Cr(III) is the dominant toxicant at some Superfund sites within the United States and therefore we are interested in its effects. Cr(III)’s mechanisms are not well studied or understood because of its low bioavailability. We have attempted to characterize the effects of Cr(III) on gene expression in the liver of adult male Fundulus heteroclitus. The NOEC and LOEC were determined at 32 and 64mg/L, respectively, by measuring growth after exposing juveniles for 30 days. Secondary exposures were performed with adult males at 32mg/L, livers excised, and RNA extracted. Microarrays were probed with cDNA from untreated or Cr(III)-exposed adult fish and gene expression was quantified. Cr(III) at 32mg/L altered the expression of 5 genes, including GSTalpha, GSTtheta, and ALDH4. Ultimately, we anticipate using this gene expression information to determine whether chromium is available at potentially adverse concentrations in contaminated sites. Keywords: dose response
Project description:Detailed analysis of genome-wide transcriptome profiling in rice root is reported here, following Cr-plant interaction. Such studies are important for the identification of genes responsible for tolerance, accumulation and defense response in plants with respect to Cr stress. Rice root metabolome analysis was also carried out to relate differential transcriptome data to biological processes affected by Cr (VI) stress in rice.
Project description:Comparison of gene expression in WT and MAL knockout (MALKO) mouse macrophages treated with 10ng/ml lipopolysaccharide (LPS) with that of mock-treated cells incubated for the same time (10 days). Cells from 4 mice of each genotype were used and each individual served as its own control. Hybridizations of treated and control samples were dye swapped.
Project description:We analyzed the genome-wide expression profile of the wild type strain and the gcn5 mutant (component of the SAGA complex) under basal and cell wall stress (CR during 3 hours) conditions.