[Cellular and molecular mechanisms of the stress response in marine bivalves]

To maintain their body integrity when aggressed, living organisms use a series of genetic and metabolic events constituting the stress response. Experiments carried out on man and superior vertebrates have shown that the stress response can be considered as a general adaptative syndrome. It constitutes one of the key elements of the defense system and can schematically be decomposed as an immediate response related to the release of preformed or formed de novo cytotoxic cell mediators and a delayed response with genomic interactions and induced protein synthesis. In invertebrates, experiments were essentially aimed at study of cytotoxic secreted agents during immediate response. However, the presence of cytokine like agents, NO-synthases and heat shock proteins were also found in molluscs, insects, annelids and echinoderrns. In marine bivalvia, informations on stress response are scarce and ftagmentary and, to the best of our knowledge, no coherent synthesis was carried out. The aim of the present work is to collect up to date results in this field and to carry out a comparative analysis of defense mechanisms known in vertebrates.