Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

Expression analysis of Gordonia sp. KTR9 upon exposure to RDX and Nitrogen limitation

ABSTRACT: Investigation of gene expression level changes in Gordonia sp. KTR9 upon exposure to RDX and Nitrogen Limitation, compared to controls with no RDX. The Gordonia sp. KTR9 strain used in this study has been previously described by Thompson KT, Crocker FH, Fredrickson HL.2005. Mineralization of the cyclic nitramine explosive hexahydro-1,3,5-trinitro-1,3,5-triazine by Gordonia and Williamsia spp. Appl Environ Microbiol. 2005 Dec;71(12):8265-72. A 12 x 135K array study using total RNA recovered from triplicate cultures of KTR9 exposed to RDX, triplicate cultures of KTR9 exposed to RDX and high nitrogen conditions, triplicate cultures of KTR9 exposed to low nitrogen, and triplicate cultures of controls exposed to high nitrogen.

ORGANISM(S): Gordonia sp. KTR9

SUBMITTER: Dawn Hancock

PROVIDER: E-GEOD-42340 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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Publications

Role of nitrogen limitation in transformation of RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) by Gordonia sp. strain KTR9.

Indest Karl J KJ Hancock Dawn E DE Jung Carina M CM Eberly Jed O JO Mohn William W WW Eltis Lindsay D LD Crocker Fiona H FH

Applied and environmental microbiology 20121228 5

The transcriptome of RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine)-degrading strain Gordonia sp. strain KTR9 and its glnR mutant were studied as a function of nitrogen availability to further investigate the observed ammonium-mediated inhibition of RDX degradation. The results indicate that nitrogen availability is a major determinant of RDX degradation and xplA gene expression in KTR9. ...[more]

PMID: 23275513

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Project description:Munitions constituents (MCs) including hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), 2,4,6-trinitrotoluene (TNT), and TNT derivatives are recognized to elicit aberrant neuromuscular responses in many species. The onset of seizures resulting in death was observed in the avian model Northern bobwhite after oral dosing with RDX beginning at 8 mg/kg/day in subacute (14 days) exposures, whereas affective doses of the TNT derivative, 2,6-dinitrotoluene (2,6-DNT), caused gastrointestinal impacts, lethargy, and emaciation in subacute and subchronic (60 days) exposures. To assess and contrast the potential neurotoxicogenomic effects of these MCs, a Northern bobwhite microarray was developed consisting of 4119 complementary DNA (cDNA) features enriched for differentially-expressed brain transcripts from exposures to RDX and 2,6-DNT. RDX affected hundreds of genes in brain tissue, whereas 2,6-DNT affected few (M-bM-^IM-$ 17), indicating that 2,6-DNT exposure had relatively little impact on the brain in comparison to RDX. Birds exhibiting RDX-induced seizures accumulated over 20M-CM-^W more RDX in brain tissues in comparison to non-seizing birds even within a common dose. In parallel, expression patterns were unrelated among seizing and non-seizing birds exposed to equivalent RDX doses. In birds experiencing seizures, genes related to neuronal electrophysiology and signal transduction were significantly affected. Comparative toxicology revealed strong similarity in acute exposure effects between RDX and the organochlorine insecticide dichlorodiphenyltrichloroethane (DDT) regarding both molecular mechanisms and putative mode of action. In a manner similar to DDT, we hypothesize that RDX elicits seizures by inhibition of neuronal cell repolarization postaction potential leading to heightened neuronal excitability and seizures facilitated by multiple molecular mechanisms. Northern Bobwhite 14 Day RDX High Dose Exposure, Brain Tissue Investigation (High Laser Intensity Scan): Juvenile male and female Northern bobwhite (12 weeks of age) were dosed with RDX by daily gavage (0, 20, 80, 125, or 180 mg/kg/day). Each treatment group included seven birds (at least three of each sex per treatment). All RDX doses in the 14-day high-dose experiment elicited seizures within 3 days of experiment initiation (Johnson et al., 2007). Microarray experiments were conducted using a balanced interwoven-loop design using Cyanine-3 (Cy3) and A647. This experiment investigated the 14-day RDX high-dose exposure. All RDX-dosed quail accumulated ~20 mg/kg RDX in brain tissues (Johnson et al., 2007) and exhibited seizures. Transcript expression was compared among three male and three female controls versus three male and three female RDX-seized quail incorporating two dye swaps per biological replicate totaling 24 microarrays. Hybridizations included four technical replicates and two dye swaps per biological replicate resulting in a total of 24 micorarrays assayed. To broaden signal detection, each microarray was scanned at high and low laser power to resolve low-intensity spots and reduce signal saturation, respectively (Skibbe et al., 2006). This dataset represents the High Intensity Scan.

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Dataset Information

Expression analysis of Gordonia sp. KTR9 upon exposure to RDX and Nitrogen limitation

Publications

Role of nitrogen limitation in transformation of RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) by Gordonia sp. strain KTR9.

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