Shanghai Collaborative Innovation for Aquatic Animal Genetics and Breeding, Shanghai Ocean University, Shanghai 201306, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China; Shanghai Engineering Research Centre of Aquaculture, Shanghai 201306, China.
Shanghai Collaborative Innovation for Aquatic Animal Genetics and Breeding, Shanghai Ocean University, Shanghai 201306, China; Shanghai Engineering Research Centre of Aquaculture, Shanghai 201306, China.
Comp Biochem Physiol A Mol Integr Physiol. 2024 Jan;287:111536. doi: 10.1016/j.cbpa.2023.111536. Epub 2023 Oct 17.
Salinity changes affect the osmotic gradient across the gill epithelium of marine species. Taurine is an important osmoregulator with a crucial role in osmoregulation in marine bivalves. This study determined the osmolality, taurine content, key enzymes involved in taurine synthesis (cysteine dioxygenase (CDO), cysteine sulfinic acid decarboxylase (CSAD), and taurine transporter (TauT)) and related gene expression in razor clam Sinonovacula constricta in response to high salt stress [high salt seawater (S30) versus high salt seawater with taurine supplementation (S30T) versus natural salinity control]. The data were recorded at 0, 6, 12, 24, 48, 72 h. Serum osmolality significantly increased under high salt conditions compared with the control group (P < 0.05). When serum osmolality had stabilized (after 48 h), there was no significant difference in serum osmolality between the S30T and control groups (P > 0.05), but serum osmolality was significantly lower in the S30 versus control group (P < 0.05). Taurine content significantly increased under high salt stress and remained high (P < 0.05). CSAD and CDO content was higher in S30 than in S30T, whereas TauT was significantly lower in S30 than in the control group eventually (P < 0.05). Expression of CDO and CSAD in the S30 and S30T groups was significantly higher than in control animals (P < 0.05), with that in S30 being higher than in S30T. By contrast, TauT expression peaked 6 h after stress in S30 and S30T, but was lower in S30 than in the control group (P < 0.05). These results demonstrate that S. constricta is an osmoconformer, with exogenous taurine relieving the stress of osmoregulation caused by insufficient endogenous taurine in cells. These findings further enhance our understanding of the regulatory mechanisms underlying the response of S. constricta to high salinity stress.
盐度变化会影响海洋物种鳃上皮的渗透梯度。牛磺酸是一种重要的渗透调节剂，在海洋双壳类动物的渗透调节中起着关键作用。本研究测定了在高盐胁迫下[高盐海水（S30）与高盐海水加牛磺酸（S30T）与自然盐度对照]，刀额新对虾渗透压、牛磺酸含量、牛磺酸合成关键酶（半胱氨酸双加氧酶（CDO）、半胱氨酸亚磺酸脱羧酶（CSAD）和牛磺酸转运体（TauT））和相关基因表达。数据在 0、6、12、24、48、72 h 时记录。与对照组相比，高盐条件下血清渗透压显著升高（P<0.05）。当血清渗透压稳定（48 h 后）时，S30T 组与对照组血清渗透压无显著差异（P>0.05），但 S30 组血清渗透压明显低于对照组（P<0.05）。高盐胁迫下牛磺酸含量显著升高，且持续升高（P<0.05）。S30 中 CSAD 和 CDO 的含量高于 S30T，而 TauT 的含量则明显低于对照组（P<0.05）。S30 和 S30T 组 CDO 和 CSAD 的表达均显著高于对照组（P<0.05），且 S30 组高于 S30T 组。相反，S30 和 S30T 中 TauT 的表达在应激后 6 h 达到峰值，但 S30 组的表达低于对照组（P<0.05）。这些结果表明，刀额新对虾是一种渗透调节动物，外源性牛磺酸缓解了细胞内牛磺酸不足引起的渗透压调节应激。这些发现进一步增强了我们对刀额新对虾对高盐胁迫反应的调节机制的理解。
