Combined analysis of mRNA–miRNA reveals the regulatory roles of miRNAs in the metabolism of clam Cyclina sinensis hepatopancreas during acute ammonia nitrogen stress

Abstract

Clam Cyclina sinensis behaves a stronger ammonia nitrogen tolerance, whereas the molecular regulation mechanism remains unknown. In the present study, C. sinensis was exposed to ammonia nitrogen (32.90 mg/L) for 0 h (the control), 12 h (T1) and 24 h (T2). Integrated analysis of miRNA-mRNA was conducted to reveal the regulatory roles of miRNAs in the metabolism of C. sinensis exposed to acute ammonia nitrogen. Numerous genes involved in detoxification and ammonia excretion expressed differently indicate that nitrogen assimilation and utilization is adjusted to accommodate ammonia exposure. The clam has to alter their glucose and lipid metabolism to meet energy requirements to adapt acute ammonia exposure in the environment. 12, 948 genes were identified as target genes of the differently expressed miRNAs. Most of mRNA–miRNA pairs were involved in metabolisms of carbohydrate, lipid and amino acid. miRNA-mRNA integrated analysis revealed involvement of Purine metabolism, Wnt signalling pathway, Hippo signalling pathway, PI3K-Akt signalling pathway in ammonia-stress response of C. sinensis. Exposed to ammonia, clam may suffer hypoxia exposure. Overall, exposed to ammonia, clam has to alter their glucose and lipid metabolism to meet energy requirements. Numerous mRNA–miRNA pairs were involved in metabolisms of carbohydrate, lipid and amino acid and miRNA can regulate the metabolism of C. sinensis by regulating the expression of target genes during acute ammonia nitrogen stress. The net result is that nitrogen assimilation and utilization is adjusted to accommodate ammonia exposure. The current study is helpful for further investigation into the ammonia nitrogen response mechanisms in mollusks.