Analysis of the miRNA expression profile of laboratory red crucian carp under low-dose caesium-137 irradiation

Radiation can cause the differential expression of biological miRNA molecules, but research on miRNAs and biological radiation damage is insufficient. This research was based on the development of the experimental animal resource laboratory red crucian carp (LRCC) to explore the feasibility of its application in the detection of low-dose ionizing radiation-induced biological damage in aquatic environments and the development of related molecular markers. Adult LRCC were irradiated with caesium-137 at 0.3 Gy, while RNA-seq and bioinformatics techniques were used to identify miRNAs that were differentially expressed relative to their levels in the nonirradiation group. Analysis of liver sections showed that liver cells in the radiation group showed nuclear pyknosis. In this study, 34 miRNAs differentially expressed in the liver of LRCC after irradiation were identified, among which seven were new crucian carp miRNAs; the prediction analysis of their target genes showed that a total of 632 target genes were predicted. The results of comprehensive GO enrichment and KEGG pathway analyses showed that these target genes were mainly involved in energy transfer and material catabolism, especially malonyl-CoA biosynthesis, acetyl-CoA carboxylase activity, fatty acid biosynthesis and metabolism, and pyruvate metabolism; in addition, the AMPK signalling pathway was the most active pathway. This study shows that LRCC have a certain sensitivity to radiation, and the miRNAs identified may be used as preselected biomarkers for radiation damage detection.