FN Archimer Export Format
PT J
TI Copper induces expression and methylation changes of early development genes in Crassostrea gigas embryos
BT 
AF SUSSARELLU, Rossana
   LEBRETON, Morgane
   ROUXEL, Julien
   AKCHA, Farida
   RIVIERE, Guillaume
AS 1:1;2:1,2;3:1;4:1;5:2;
FF 1:PDG-RBE-BE-LEX;2:PDG-RBE-BE-LEX;3:PDG-RBE-BE-LEX;4:PDG-RBE-BE-LEX;5:;
C1 IFREMER, Lab Ecotoxicol, Rue Ile dYeu, F-44311 Nantes, France.
   Univ Caen Basse Normandie, UMR BOREA, F-14032 Caen, France.
C2 IFREMER, FRANCE
   UNIV CAEN BASSE NORMANDIE, FRANCE
SI NANTES
SE PDG-RBE-BE-LEX
IN WOS Ifremer jusqu'en 2018
   copubli-france
   copubli-univ-france
IF 3.794
TC 30
UR https://archimer.ifremer.fr/doc/00417/52856/53756.pdf
LA English
DT Article
DE ;Oyster;Embryotoxicity;Copper;Gene expression;DNA methylation
AB Copper contamination is widespread along coastal areas and exerts adverse effects on marine organisms such as mollusks. In the Pacific oyster, copper induces severe developmental abnormalities during early life stages; however, the underlying molecular mechanisms are largely unknown. This study aims to better understand whether the embryotoxic effects of copper in Crassostrea gigas could be mediated by alterations in gene expression, and the putative role of DNA methylation, which is known to contribute to gene regulation in early embryo development. For that purpose, oyster embryos were exposed to 4 nominal copper concentrations (0.1, 1, 10 and 20 μg L−1 Cu2+) during early development assays. Embryotoxicity was monitored through the oyster embryo-larval bioassay at the D-larva stage 24 h post fertilization (hpf) and genotoxicity at gastrulation 7 hpf. In parallel, the relative expression of 15 genes encoding putative homeotic, biomineralization and DNA methylation proteins was measured at three developmental stages (3 hpf morula stage, 7 hpf gastrula stage, 24 hpf D-larvae stage) using RT-qPCR. Global DNA content in methylcytosine and hydroxymethylcytosine were measured by HPLC and gene-specific DNA methylation levels were monitored using MeDIP-qPCR. A significant increase in larval abnormalities was observed from copper concentrations of 10 μg L−1, while significant genotoxic effects were detected at 1 μg L−1 and above. All the selected genes presented a stage-dependent expression pattern, which was impaired for some homeobox and DNA methylation genes (Notochord, HOXA1, HOX2, Lox5, DNMT3b and CXXC-1) after copper exposure. While global DNA methylation (5-methylcytosine) at gastrula stage didn’t show significant changes between experimental conditions, 5-hydroxymethylcytosine, its degradation product, decreased upon copper treatment. The DNA methylation of exons and the transcript levels were correlated in control samples for HOXA1 but such a correlation was diminished following copper exposure. The methylation level of some specific gene regions (HoxA1, Hox2, Engrailed2 and Notochord) displayed changes upon copper exposure. Such changes were gene and exon-specific and no obvious global trends could be identified. Our study suggests that the embryotoxic effects of copper in oysters could involve homeotic gene expression impairment possibly by changing DNA methylation levels. 
PY 2018
PD MAR
SO Aquatic Toxicology
SN 0166-445X
PU Elsevier Science Bv
VL 196
UT 000426411600009
BP 70
EP 78
DI 10.1016/j.aquatox.2018.01.001
ID 52856
ER

EF