Glycogen Variations and Glycometabolism During the Gametogenesis Cycle of Jinjiang Oyster Crassostrea (magallana) Ariakensis

Glycogen, a highly branched polysaccharide of essential energy and carbon resource, is an important flavor quality trait of oysters, and its content is closely linked to the reproductive cycle of these mollusks. However, there is a significant lack of research on the regulatory mechanisms governing glycogen in oysters. Here, we investigated the variations in glycogen levels during the reproductive cycle of Jinjiang oyster Crassostrea (Magallana) ariakensis. It revealed that glycogen content was highest during the formative stage and lowest during the mature stage in gonadal tissues. Subsequently, transcriptome and metabolome analyses were conducted, revealing 3016 differentially expressed genes (DEGs) and 162 differentially accumulated metabolites (DAMs). Comprehensive analysis indicated that glycogenesis, glycogenolysis, glycolysis, and tricarboxylic acid (TCA) cycle played crucial roles in energy supply during the formative stage. Gluconeogenesis was more important during the mature stage as it facilitated glycogen storage for reproduction preparation. These findings provide valuable insights into the mechanisms underlying gonad development-related glycogen metabolism and offer a theoretical foundation for enhancing oyster flavor.