急性低温和复温对青田田鱼鳃组织代谢的影响

Effects of acute cold stress and rewarming on the metabolism of gill tissue of Qingtian paddy field carp(Cyprinus carpio var. qingtianensis

  • 摘要: 【目的】 青田田鱼在浅水环境中经常面临急性低温胁迫,探究青田田鱼在急性低温和复温环境下的生理响应机制,为青田田鱼科学越冬和耐低温品种选育提供理论依据。【方法】 通过液相色谱—质谱(LC-MS)非靶向代谢组学技术,提取9.0 ℃胁迫6 h(CO组)、升温至28.0 ℃复温恢复6 h(RE组)和28.0 ℃对照组(Con组)青田田鱼鳃组织样本代谢峰。预处理后的代谢组数据与数据库匹配鉴定代谢物种类。通过主成分分析(PCA)和正交最小偏二乘判别分析(OPLS-DA)鉴定代谢组学数据的可靠性。根据Student’s test 检验的P值(P<0.05)和OPLS-DA模型得到的变量权重值(VIP>1)筛选组间差异代谢物。对差异代谢物进行KEGG信号通路富集分析,并用Fisher精确检验分析筛选与急性低温和复温最相关的代谢通路。对重要代谢通路制作聚类热图,显示组间差异和代谢物水平变化趋势。【结果】 PCA和OPLS-DA分析结果显示,组内样本聚集,组间样本分离,组间的代谢物水平存在显著差异。OPLS-DA得分图显示各组Q2累计值均在0.5以上,R2Y累积值均接近1.0,模型具有较高的解释度和可靠性;共鉴定到1222个代谢物,其中CO vs Con,RE vs CO和RE vs Con分别筛选鉴定出232、238和300种显著差异代谢物(P<0.05)。各组间差异代谢物主要富集在花生四烯酸代谢、甘油磷脂代谢、类固醇激素生物合成和嘌呤代谢等代谢途径;急性低温胁迫下,皮质醇水平上调,而花生四烯酸及其代谢物和甘油磷脂代谢物下调。复温后花生四烯酸、甘油磷脂代谢物和嘌呤代谢物相对Con组下调,皮质醇含量下调,牛磺酸含量上调。【结论】 急性低温可导致青田田鱼免疫、物质转运和信号传递等功能异常。皮质醇的合成和代谢可能是青田田鱼抵抗急性低温胁迫的重要机制。复温后青田田鱼鳃组织损伤在短期内无法得到完全恢复。牛磺酸合成可能是青田田鱼在复温过程中的重要恢复机制。

     

    Abstract: 【Objective】 Qingtian paddy field carp(Cyprinus carpio var. Qingtianensis,PF carp)was frequently exposed to the stress of acute cold stress in ambient temperatures in shallow water environments. The study aimed to investigate the physiological response mechanism of PF carp in acute cold stress and rewarming,which could provide basis for scientific overwintering of PF carp and breeding of low-temperature-tolerant varieties. 【Method】 The metabolic peaks in gill tissue of PF carp were extracted by liquid chromatography-mass spectrometry(LC-MS)non-targeted metabolomics in the 9.0 ℃ cold stress for 6 h(CO group)and subsequent rewarming recovery to 28.0 ℃ for 6 h(RE group)and the 28.0 ℃ control group(Con group). The pre-processed metabolomics data were matched with the database to identify the metabolites. The reliability of metabolomics data was identified by principal component analysis(PCA)and orthogonal least-squares discriminant analysis(OPLS-DA). The differential metabolites between groups were screened according to the P value of Student’s test(P<0.05)and the variable weight value of OPLS-DA model(VIP>1). The KEGG signal pathway enrichment analysis of differential metabolites was performed. The metabolic pathways mostly associated with acute cold stress and rewarming were screened by Fisher test. Cluster heat maps were made for important metabolic pathways to show the differences between groups and the changing trend of metabolite content. 【Result】 The PCA and OPLS-DA analysis showed that samples were aggregated within group,and were separated between groups. There were significant differences in metabolite levels between groups. The OPLS-DA score chart showed that the cumulative Q2 values of all groups were above 0.5,and the cumulative R2Y values were close to 1.0. The model had high interpretability and reliability. A total of 1222 metabolites were identified,among which 232,238,300 significantly different metabolites were screened and identified respectively in CO vs Con,RE vs CO and RE vs Con(P<0.05). Differential metabolism between groups were mainly enriched in metabolic pathways such as arachidonic acid metabolism,glycerophospholipid metabolism,steroid hormone biosynthesis and purine metabolism. Specifically,under acute cold stress,cortisol levels was up-regulated,but arachidonic acid and its metabolites,glycerophospholipid metabolites were down-regulated. After rewarming,the metabolism of arachidonic acid and glycerophospholipid,purine metabolism were down-regulated compared with Con group,while the content of cortisol was down-regulated and the content of taurine was up-regulated. 【Conclusion】 Acute cold stress can lead to immunosuppression,abnormalities in substance transport and signal transmission in PF carp. Cortisol synthesis and metabolism are important mechanisms for resistance to acute cold stress. Gill tissue damage can not be fully recovered in the short term after rewarming. Taurine synthesis may be an important recovery mechanism of PF carp after rewarming.

     

/

返回文章
返回