Comparative Effects of Dietary Methylmercury on Gene Expression in Liver, Skeletal Muscle, and Brain of the Zebrafish ( Danio rerio )
Effects of dietary methylmercury (MeHg) on gene expression were examined in three organs (liver, skeletal muscle, and brain) of the zebrafish (Danio rerio). Adult male fish were fed over 7, 21, and 63 days on three different diets: one control diet (C0: 0.08 microg of Hg g(-1), dry wt) and two diets (C1 and C2) contaminated by MeHg at 5 and 13.5 microg of Hg g(-1), dry wt. Total Hg and MeHg concentrations were determined in the three organs after each exposure duration, and a demethylation process was evidenced only in the liver. Thirteen genes known to be involved in antioxidant defenses, metal chelation, active efflux of organic compounds, mitochondrial metabolism, DNA repair, and apoptosis were investigated by quantitative real-time RT-PCR and normalized according to actin gene expression. Surprisingly, no change in the expression levels of these genes was observed in contaminated brain samples, although this organ accumulated the highest mercury concentration (63.5 +/- 4.4 microg g(-1), dry wt after 63 days). This lack of genetic response could explain the high neurotoxicity of MeHg. coxI and cytoplasmic and mitochondrial sod gene expressions were induced early in skeletal muscle and later in liver, indicating an impact on the mitochondrial metabolism and production of reactive oxygen species. Results demonstrated that skeletal muscle was not only an important storage reservoir but was also affected by MeHg contamination. The expression of the metallothionein mt2 and the DNA repair rad51 genes was up-regulated in liver between 21 and 63 days, whereas in skeletal muscle, mt2 remained uninduced, and gadd and rad51 were found to be repressed.
(Environmental Science and Technology. vol. 39, n° 0013-936X, pp. 3972-3980, 01/06/2005)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Interaction between N-species and Mn-oxides in rapid deposited sediment layers : Field observations and experiments.
(01/06/2005)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Tidal inlet response to sediment infilling of the associated bay and possible implications of human activities: the Marennes-Oléron Bay and the Maumusson Inlet, France
(Continental Shelf Research. vol. 25, n° 0278-4343, pp. 1115-1131, 01/06/2005)
CLDG, ULR, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, BRGM
Radionuclides transfer between water and atmosphere in the Loire estuary (FLORE project)
In estuaries, volatiles radionucleides (14 C, 3 H, 131 I) originating from anthropogenic liquid waste release from nuclear reactor or hospitals are potentially transferable to the atmosphere. Due to the high biologic activity, the degradation of organic matter produce carbon dioxide fluxes to the atmosphere allowing transfer of 14 CO 2 released by nuclear industry. Similarly tritium is transfered to the atmosphere trough evaporation process. We present here, results obtained during FLORE-1 cruise in February 2003, a winter period when biological activity is supposed to be low. The first results of iodine 131 distribution and estimations of radiocarbon and tritium fluxes are presented.
(Radioprotection. vol. 40, n° 0033-8451, pp. S557-S562, 01/05/2005)
LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, GEOTRAC, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, IRSN/PSE-ENV/SRTE/LRC, IRSN/PSE-ENV/SRTE, IRSN, EAMEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Synergic effect of gold mining and damming on mercury contamination in fish
(Environmental Science and Technology. vol. 39, n° 0013-936X, pp. 2248-2254, 15/04/2005)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UR MALY, IRSTEA, LMBA, UBS, UBO EPE, CNRS, IFREMER
Multiproxy approach for the reconstruction of the glacial ocean surface (MARGO)
(Quaternary Science Reviews. vol. 24, n° 0277-3791, pp. 813-819, 01/04/2005)
RHUL, ICTA, UAB, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, PALEOCEAN, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, CAU
Reconstruction of sea-surface temperatures from assemblages of planktonic foraminifera: multi-technique approach based on geographically constrained calibration data sets and its application to glacial Atlantic and Pacific Oceans
(Quaternary Science Reviews. vol. 24, n° 0277-3791, pp. 951-998, 01/04/2005)
CAU, CAM, NTOU, CEOAS, OSU, ANU, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, PALEOCEAN, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UoN
Sea-surface temperature and sea ice distribution of the Southern Ocean at the EPILOG Last Glacial Maximum—a circum-Antarctic view based on siliceous microfossil records
Based on the quantitative study of diatoms and radiolarians, summer sea-surface temperature (SSST) and sea ice distribution were estimated from 122 sediment core localities in the Atlantic, Indian and Pacific sectors of the Southern Ocean to reconstruct the last glacial environment at the EPILOG (19.5-16.0 ka or 23 000-19 000 cal yr. B.P.) time-slice. The statistical methods applied include the Imbrie and Kipp Method, the Modern Analog Technique and the General Additive Model. Summer SSTs reveal greater surface-water cooling than reconstructed by CLIMAP (Geol. Soc. Am. Map Chart. Ser. MC-36 (1981) 1), reaching a maximum (4-5 1C) in the present Subantarctic Zone of the Atlantic and Indian sector. The reconstruction of maximum winter sea ice (WSI) extent is in accordance with CLIMAP, showing an expansion of the WSI field by around 100% compared to the present. Although only limited information is available, the data clearly show that CLIMAP strongly overestimated the glacial summer sea ice extent. As a result of the northward expansion of Antarctic cold waters by 5-101 in latitude and a relatively small displacement of the Subtropical Front, thermal gradients were steepened during the last glacial in the northern zone of the Southern Ocean. Such reconstruction may, however, be inapposite for the Pacific sector. The few data available indicate reduced cooling in the southern Pacific and give suggestion for a non-uniform cooling of the glacial Southern Ocean. This study is part of MARGO, a multiproxy approach for the reconstruction of the glacial ocean surface. r
(Quaternary Science Reviews. vol. 24, n° 0277-3791, pp. 869-896, 01/04/2005)
AWI, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, AWI
La Grande Vasière : architecture, mise en place et estimation des facteurs de son évolution.
(22/03/2005)
GM, IFREMER, M2C, UNICAEN, NU, INSU - CNRS, UNIROUEN, NU, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LDO, INSU - CNRS, UBO EPE, CNRS, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, NU
Goldmining and mercury contamination of the piscivorous fish Hoplias aimara in French Guiana (Amazon Basin)
(Ecotoxicology and Environmental Safety. vol. 60, n° 0147-6513, pp. 315-323, 01/03/2005)
LMBA, UBS, UBO EPE, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS