Obtaining cell proliferation for chromosome preparation in gill tissue culture of the oyster Crassostrea gigas.

The present results were obtained in the course of theadjustment to the oyster Crassostrea gigas of atissue culture technique recently developed for themussel Mytilus edulis. With respect to theprotocol originally described, the effects of twomodifications are reported: (1) replacement of chickembryo extract by chicken serum for medium enrichment,and (2) achievement of cultures in rotating tubes(roller drum) in place of stationary condition.Paradoxical results were obtained: whereas takenseparately, each modification exerted a negativeeffect which is statistically significant, combinated,they exerted a high positive effect representing athree-fold increase of the mean metaphase spreadnumber per slide (i.e. 71.5). Hypotheses are proposedto explain the mechanisms involved. It is suggestedthat the two additives work differently and thatcultures with chick embryo extract enriched mediumcould not withstand the condition generated by theroller drum. Conversely, cultures performed withchicken serum enriched medium would be in a betterphysiological state and the roller allow to obtain acell proliferation after only six days of incubation.