significantly up-regulated (Pb0.05) in gill and digestive tract tissuesafter Aroclor 1254 induction compare to non-treated and methanolinjected abalone groups, suggesting that abalone has a potential use inassessing the impact of marine pollutants with the application of geneexpression concept. In addition, purified recombinant aCuZn–SODfusion protein was shown to reduce O2

− radical generated by xanthineoxidase assay, showing CuZn–SOD is a functionally active antioxidantenzyme in disk abalone.

doi:10.1016/j.cbpa.2008.05.153

16.Heat shock proteins (Hsps), biomarkers of toxicity ofxenobiotic agents?

M.C. Guisasola (Med & Surgical Unit, Spain); E. Dulin (Clinical Biochem-istry Dep, Spain); M.J. Sánchez, P. García-Barreno (Med & Surgical Unit,Hospital General Universitario Gregorio Maranon, Madrid. Spain)

The biogenesis of stress proteins or the activation of theirrespective genes could satisfy all the requirements of an environ-mental toxicity molecular biomarker. For human environmentalmedicine, circulating leukocytes in peripheral blood (PMNs) mayconstitute an ideal and reproducible biosensor that is easilyaccessible and always available for evaluation of exposure to – orthe effects of – environmental stress.

In the present study, our objectives were to study in a representativesample of general population (N=269, 131male, 138 female) possiblepolymorphisms (SNPs) of the hsp70i gene regulator region (NT_007592)in PMNs, Hsp70i levels in serum and in PMNs, and if immunoreactivityto HSPs exists in tobacco smokers (TS) (N=74) compared to no smokers(N=195). There wasn't significant differences in serum [Hsp70i]between both groups, but TS showed an increase in [Hsp70i] in PMNsand in Abs antiHsp70i (p Pb0.05, Anova one way). None of the threeSNPs detected in hsp72 promoter -326ANC,-97TNC and -27GNC wererelated to tobacco exposition. In conclusion, cigarette smoke (CS) is apotent sourceof oxidants leading to oxidative stress that inducesHsps innormal human PMNs. CS induces a specific differential gene expressionpattern in vivo, whichmay be instrumental in identifying themolecularmechanisms leading to the onset of inflammatory/autoinmune whichhas been associated with multiple steps in CS-related carcinogenesis.Hsps must be considered as efficient biomarkers of environmentalstressors. Grants from FIS 03/1308 and FMM.

doi:10.1016/j.cbpa.2008.05.154

17.Gene characterization and expression analysis of peroxiredoxin 6in disk abalone (Haliotis discus discus) by H2O2 oxidative stressand Vibrio alginolyticus infection

C. Nikapitiya, Y.H. Kim, J. Lee (Department of Biotechnology, College ofOcean Science, Cheju National University, South Korea)

Phagocytosis is one of the important immune defense reactions ofinvertebrates when the organism is attacked bymicroorganisms. Massproduction of reactive oxygen species (ROS) is generated during thephagocytosis and they are constantly generated during normalcellular metabolism. ROS can cause serious cell damage. Peroxiredox-ins (Prxs) are a newly defined family of antioxidants which foundubiquitously in prokaryotes and eukaryotes. Peroxiredoxin 6 (Prx6) isa bi-functional protein with both glutathione peroxidase andphospholipase A2 (PLA2) enzymatic activities.

In this study, we characterized cDNA encoding antioxidant enzymePrx6 from the abalone Haliotis discus discus. Further, we studied thegene expression of Prx6 in vivo by causing oxidative stress from intramuscular injection of H2O2 and Vibrio alginolyticus. The full lengthcDNA consist of 1461 bp with an open reading frame of 654 bp,encoding 218 amino acids. The predicted molecular mass andIsoelectric point of protein were 24 kDa and 7.3, respectively.Sequence comparison showed that Prx6 of disk abalone had 69%and 67% identity to Xenopus tropicalis and Arenicola marina Prx6,respectively. One cysteine residue was positioned within Prx6signature motif, PVCT which is conserved among the Prx6 of variousspecies. RT-PCR results showed that a single intramuscular injection ofH2O2 induced Prx6 mRNA expression in gill and digestive tract after3 h and 6 h of administration. V. alginolyticus injected animals showedthat the expression was up-regulated initially within 12 h post-injection in both gill and digestive tract compared to control.

These data suggests that Prx6 has an important role in theprotection against oxidative stress caused by various stress conditions.

doi:10.1016/j.cbpa.2008.05.155

18.Hypoxia stress in the pacific oyster Crassostrea gigas: Atranscriptomic approach

R. Sussarellu, D. Moraga (Institut Universitaire Européen de la Mer,Université de Bretagne Occidentale, France)

Coastal ecosystems are subjected to increased anthropogenicpollution and other environmental stressors; of these, marine hypoxiahas become a major ecological concern. Benthic communities are themost sensitive parts of the coastal ecosystem to eutrophication andresulting hypoxia. Some of these stressors are also known to inducemodifications in the genetic structure of populations throughdifferential mortality of individuals carrying specific genotypes.Large-scale summer mortality events have been observed in Pacificoyster Crassostrea gigas, a complex combination of environmental andbiological parameters has been suggested as the cause. Recent studiesshowed that susceptibility or resistance to summer mortality inC. gigas has a strong genetic basis and a high heritability of thephenotype; therefore, two groups of oysters were selected (‘R’ and ‘S’,resistant and susceptible respectively).

The response of the Pacific oyster to hypoxia under experimentalconditions was investigated using S and R families. A cDNAmicroarrayanalysis was performed using RNA from digestive glands on amicroarray containing 9056 sequences. The aim was to characterizegenetic markers or metabolic pathways in the Pacific oyster, C. gigas,that could be linked with responses to hypoxia stress and to in-vestigate different expression patterns between R and S families.

This researchwill characterizepotential geneticmarkers that couldbeused in future environmental monitoring, and could identify previouslyunknown mechanisms of stress tolerance in marine mollusc species.

doi:10.1016/j.cbpa.2008.05.156

19.Study of the molecular response to thermal challenge of thehydrothermal annelid Paralvinella grasslei

A. Tanguy, D. Jollivet (CNRS-UPMC, UMR 7144 Adaptation et Diversitéen Milieu Marin, France); B. Shillito (CNRS-UPMC UMR 7138‘Systématique, Adaptation et Evolution, France); O. Lecompte (IGBMC,CNRS/INSERM/Université Louis Pasteur, UMR7104/U596, France)

S42 Abstracts / Comparative Biochemistry and Physiology, Part A 151 (2008) S37–S43