Impact of reproductive activity on physiological metabolism and molecular regulation in the Genus scallopus(Mizuhopecten yessoensis)

Genus scallopus(Mizuhopecten yessoensis), a commercially important shellfish species in China, suffers a persistently high post-spawning mortality rate, severely constraining industry development. Thus, this study investigated the physiological and molecular impact of reproductive activity on M. yessoensis. There were significant decreases (P <0.05) in nutritional components (crude protein, crude lipid, and glycogen content) within the gonads before and after spawning, with a particularly pronounced reduction in crude lipids. Histological examination showed that, post spawning, lumens formed within the gonadal follicles of both sexes following gamete release, accompanied by decreased germ cell numbers. Enzyme activity assays indicated significant changes in enzyme activities post spawning. Superoxide dismutase and lactate dehydrogenase exhibited significant differences (P <0.01) in the female mantle. ATPase content displayed a decreasing trend in all tissues of both male and female scallops. Alanine aminotransferase showed significant differences (P <0.01) in the gonads and adductor muscles, and aspartate aminotransferase activity increased significantly (P <0.05) in the adductor muscles, of both male and female scallops. Gonadal metabolomics analysis identified 1,644 differential metabolites between pre- and post-spawning periods, primarily enriched in lipid and amino acid metabolic pathways. Female metabolic changes were concentrated in lipid and amino acid metabolism, whereas males showed alterations in sulfur-containing compound metabolism. In summary, the reproductive process significantly impacts the physiological status and metabolic patterns of M. yessoensis, with distinct variations between sexes. This study provides fundamental data for in-depth analysis of energy allocation during bivalve reproduction and lays a theoretical foundation for exploring the regulatory networks of reproductive metabolism in M. yessoensis at the molecular level.

虾夷扇贝（Mizuhopecten yessoensis）是我国重要的经济贝类，但其产卵后死亡率持续居高不下，严重制约了产业发展。为此，本研究探究了繁殖活动对虾夷扇贝的生理与分子层面影响。
研究发现，产卵前后性腺中的营养成分（粗蛋白、粗脂肪与糖原含量）均显著下降（P<0.05），其中粗脂肪的降低幅度尤为显著。
组织学检测结果显示，产卵后雌雄个体的性腺滤泡内均因生殖细胞释放形成管腔，且生殖细胞数量显著减少。
酶活性检测结果表明，产卵后多种酶活性发生显著变化：雌性外套膜中的超氧化物歧化酶（superoxide dismutase）与乳酸脱氢酶（lactate dehydrogenase）活性存在极显著差异（P<0.01）；雌雄个体各组织中的ATP酶（ATPase）活性均呈下降趋势。雌雄个体的性腺与闭壳肌中谷丙转氨酶（alanine aminotransferase）活性均存在极显著差异（P<0.01）；而谷草转氨酶（aspartate aminotransferase）活性在闭壳肌中显著升高（P<0.05）。
性腺代谢组学分析显示，产卵前后共鉴定出1644个差异代谢物，主要富集于脂质代谢与氨基酸代谢通路。
雌性个体的代谢变化主要集中于脂质与氨基酸代谢，而雄性个体则表现为含硫化合物代谢通路的改变。
综上，繁殖过程对虾夷扇贝的生理状态与代谢模式具有显著影响，且雌雄个体间存在明显差异。本研究为深入分析双壳类繁殖过程中的能量分配机制提供了基础数据，同时为从分子层面解析虾夷扇贝繁殖代谢调控网络奠定了理论基础。