Cette note de synthese des travaux realises au laboratoire de Genetique, Aquaculture et Pathologie de la station IFREMER de La Tremblade, dans le cadre de l'etude du virus de type . herpes et de la mise au point des methodes de diagnostic fait suite a la precedente note (fin mai 1996). Les resultats obtenus concernant les analyses protocolaires et hors protocoles, ainsi que les resultats experimentaux deja disponibles sont donnees et commentes en quatre points. Cette etude est soutenue par la Region Poitou-Charente et la Region Pays de Loire.

Pacific oyster,Crassostrea gigas, is the most economically important specie to the world shellfish breeding. It is important to note that infectious diseases, particularly viruses, may be hazardous for theC. gigas live-stocks. The study of these viral diseases and the development of diagnosis method need the establishment of in vitro methods for viral multiplication. As no oyster cell line is available actually, we have developed a procedure for primary culture of heart cells which could enable to study molluscan viruses in vitro, and could also provide a diagnosis method based on the search of eventual cytopathogen viral effects. Cells fromC. gigas ventricle of heart were dissociated by trypsin-EDTA treatment and the mechanical action of a Dounce type homogeneizer. The cells were inoculated in previously poly-D-lysin coated flasks. The optimised culture medium was L-15 (Leibovitz) prepared three fold concentrated, then diluted half with sea water, this mixture was supplemented with 10% FCS and 5%C. gigas hemolymph. Different cell types could be identified by transmission electron microscopy analysis, as mostly cardiomyocytes, fibroblast-like cells and pigmented cells, but also haemocytes were present in the cultures.