Gametogenesis of the Pacific oysterCrassostrea gigasfollows an annual cycle. In this work, we used contrasting dietary conditions (fed and unfed) for a preconditioning treatment in order to impact glycogen storage
supporting reproductive pathways in diploid and triploid animals before a broodstock conditioning treatment. In diploid oysters, food deprivation during preconditioning led to reduced gonia proliferation as demonstrated by lower PCNA (Proliferating Cell Nuclear Antigen) expression and subsequently, the reproductive
effort was significantly reduced. For triploid animals exhibiting arrested gametogenesis, dietary conditions
impacted the ratio ofα(animals with unlocked gametogenesis) andβ(animals with locked gametogenesis).
Thermal stress applied to these conditioned animals confirmed the weakness of diploid animals with high
stored reserves and intense reproductive effort,versuslow reproductive effort. Moreover, only low mortalities were observed for triploid animals whatever the reproductive status. The involvement of the insulin
pathway in the regulation of gametogenesis and storage rebuilding was assessed by measuring an increased
expression of CIR (C. gigasinsulin related receptor) in unfed oysters.