Dynamic Changes in Serum Biochemical Indices and Alternative Splicing Events Revealed Molecular Regulatory Mechanisms...

Copper (Cu) is a common heavy metal pollutant in aquatic environment, jeopardizing the life safety of aquatic animals. This study aims to investigate the effects of Cu²⁺ stress on the serum biochemical indicators and alternative splicing(AS) of the liver in rainbow trout. In this study, rainbow trout were divided into a control group and 3 treatment group (75 µg/L, 150 µg/L, and 300 µg/L of Cu²⁺), which were stressed for 4 d, and restored for 2 d. We determined the dynamics of serum antioxidant indices, and analyzed the changes in liver AS by RNA-seq. The results showed that T-SOD, CAT and MDA were significantly increased during Cu stress and recovery, whereas the LDH content in the treated group showed a tendency to increase and then decrease. By analyzing the RNA-seq results, we identified 23,901 AS events from 11,062 genes. Analysis by KEGG enrichment revealed that the PPAR signaling pathway, fatty acid degradation, pyruvate metabolism, fatty acid biosynthesis, drug metabolism involving other enzymes, and propionic acid metabolism signaling pathways coexisted in multiple comparison groups. In conclusion, Cu stress induces oxidative stress and affects lipid metabolism in the liver of rainbow trout, and alternative splicing plays an important role in regulating the organism's response to Cu stress. The present study provides a reference for the prevention and control of heavy metal pollution in aquatic environment.