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(W/MF133) Differential gene expression in the zebra mussel (dreissena polymorpha) in response to xenobiotic exposure. Bultelle, Florence1, Panchout, Mélanie1, Leboulenger, François1, Danger, Jean-Michel1, 1 ABSTRACT- Differential Display Polymerase Chain Reaction (DD-PCR) was conducted in order to identify genes that are differentially regulated by xenobiotics in Dreissena polymorpha. Animals were collected in the Seine river in Rouen (France) and subsequently submitted to a 2-week decontamination period in mineral water. One group of animals was then exposed for 4 or 8 hours to either Aroclor 1254 or a mixture of Aroclor 1254 and 3-methyl-cholantrene while the control group remained untreated. Messenger RNAs from whole zebra mussels were then isolated and reverse transcribed. DD-PCR was conducted in presence of 33P-dCTP by using a set of 18 combinations of random 25mers and oligo(dT) derived primers. A total of 56 radiolabelled bands were identified as corresponding to potentially regulated cDNA products following analysis by polyacrylamide gel electrophoresis. These PCR amplification products were controlled by reverse Northern-Blot in order to ensure that they did not correspond to false positives. PCR products that actually correspond to differentially expressed cDNA are currently being used as probes for screening a whole zebra mussel cDNA library constructed in Key words: zebra mussel, biomarkers, differential display PCR, differential gene expression |
ZAPII. In addition, a differential cDNA library has been constructed by subtractive PCR in the plasmid vector pGEM-T. This will also be used for isolating clones that are regulated by xenobiotics. Identification of the isolated clones will eventually be carried out by in silico screening of genome data banks. These cDNAs encode proteins that are potential biomarkers of exposure to xenobiotics. F. Bultelle is recipient of a doctoral fellowship of the Conseil Régional de Haute-Normandie. Financial supports were from the Agence de l'Eau Seine-Normandie and the Région de Haute-Normandie (Seine-Aval II Program).