The pacific oyster Crassostrea gigas is a successive protandric irregular hermaphrodite. The factors involved in the first gonadic differentiation in juveniles and those involved in sex reversal in adults are still unknown. This thesis consisted in the identification of molecular factors of the oyster’s gonadic differentiation during its adult cycle and its development. Thus, the respective orthologs to a DM-family factor and to Foxl2, Cg-DMl and Cg-Foxl2, have been characterized in the oyster by RT-PCR. Their study by real-time PCR, in situ hybridization and immunohistochemistry, has highlighted a ubiquitous expression of Cg-DMl in potentially proliferating / differentiating cells in the gonads of both sexes. The Cg-Foxl2 expression is specific to the... |