Project description:The mechanisms of heavy metal accumulation in primary producers and the damage and stress response induced by heavy metals is not well understood. We used UHTS to analyze the transcriptomic response of Elodea nuttallii to heavy metal pollution. We exposed shoots of E. nuttallii for 24 h to increasing concentrations of Hg and Cd. Using Illumina RNA-Seq, we have generated over 50 million 54 nt paired end reads and 14 million single end reads, which we used for de novo assembly of the E. nuttallii transcriptome.
Project description:The mechanisms of metal accumulation and toxicity in primary producers are not well understood. In a previous study (deposited in ArrayExpress archive under accession E-MTAB-892), we generated a dataset giving a fist insight into transcriptomic response of the aquatic macrophyte Elodea nuttallii to Hg and Cd exposure. In the present study we aimed to extend this investigation to different Hg-species, dose-response effects and multiple stress exposure. We therefore investigated the transcriptomic response of Elodea nuttallii to Hg, methyl-Hg, Cu and ultraviolet-B (UV-B) exposure. We applied different concentrations of Hg and methyl-Hg in order to study dose-response effects. Combined exposures of Hg and UV-B were conducted in order to assess interaction effects of multiple factors. Plants were exposed up to 24 h, RNA was extracted using Tri reagent, libraries prepared according to Illumina standard protocols and sequencing was done on Illumina HiSeq 2000. After quality check, raw sequence reads were assembled into contigs. About 160 Mbp assembled sequence information were generated in this study.
Project description:From the results of gene expression analyses of HepG2 under the exposure of 2,3-Dimethoxy-1,4-naphthoquinone (DMNQ), N-nitrosodimethylamine (DMN), phenol and six heavy metals We showed that biological action of six heavy metals were clearly related to that of DMNQ and distinguishable from the other chemicals. These results suggest that oxidative stress is major apparent biological action of high dose heavy metals, supporting the previous reports. Keywords: other
Project description:Environmental contamination from heavy metals poses a global concern for the marine environment, as heavy metals are passed up the food chain and persist in the environment long after the pollution source is contained. Cnidarians, dating back to 700 million years ago, play an important role in shaping marine ecosystems, but environmental pollution profoundly affects their vitality. Among the cnidarians, the sea anemone Nematostella vectensis is an advantageous model for addressing questions in molecular ecology and toxicology as it tolerates extreme environments and its genome has been published. Here we employed a transcriptome-wide RNA-Seq approach to analyze N.vectensis molecular defense mechanisms against four heavy metals: Hg, Cu, Cd and Zn. Altogether, more than 5000 transcripts showed significant changes in gene expression, with Hg having the greatest impact on up-regulating transcripts, followed by Cu, Cd and Zn. We identified, for the first time, co-up-regulation of immediate-early transcription factors such as Egr1, AP1 and NF-κB. Time-course analysis of these genes revealed their early expression as rapidly as one hour after exposure to heavy metals, suggesting that they may complement or substitute for the roles of the metal mediating Mtf1 transcripton factor. We further characterized regulation of a large array of stress-response gene families including Hsp, ABC, CYP members and phytochelatin synthase that may regulate synthesis of the metal-binding phytochelatins instead of the methallothioneins that are absent from Cnidaria genome. This study provides mechanistic insight into heavy-metal toxicity in N.vectensis and sheds light on ancestral stress adaptations.
Project description:Environmental contamination from heavy metals poses a global concern for the marine environment, as heavy metals are passed up the food chain and persist in the environment long after the pollution source is contained. Cnidarians, dating back to 700 million years ago, play an important role in shaping marine ecosystems, but environmental pollution profoundly affects their vitality. Among the cnidarians, the sea anemone Nematostella vectensis is an advantageous model for addressing questions in molecular ecology and toxicology as it tolerates extreme environments and its genome has been published. Here we employed a transcriptome-wide RNA-Seq approach to analyze N.vectensis molecular defense mechanisms against four heavy metals: Hg, Cu, Cd and Zn. Altogether, more than 5000 transcripts showed significant changes in gene expression, with Hg having the greatest impact on up-regulating transcripts, followed by Cu, Cd and Zn. We identified, for the first time, co-up-regulation of immediate-early transcription factors such as Egr1, AP1 and NF-κB. Time-course analysis of these genes revealed their early expression as rapidly as one hour after exposure to heavy metals, suggesting that they may complement or substitute for the roles of the metal mediating Mtf1 transcripton factor. We further characterized regulation of a large array of stress-response gene families including Hsp, ABC, CYP members and phytochelatin synthase that may regulate synthesis of the metal-binding phytochelatins instead of the methallothioneins that are absent from Cnidaria genome. This study provides mechanistic insight into heavy-metal toxicity in N.vectensis and sheds light on ancestral stress adaptations. 4 metals were tested in triplicates in comparison to control (4 replicates)