Abstract:Aquaporins are a family of cell membrane proteins, and their key role is to specifically transport water molecules and other neutral metabolic molecules. Moreover, aquaporins play an important role in regulating the balance between internal and external osmotic pressure in organisms. Here, aquaporin 4 and 11 genes from Exopalaemon carinicauda were successfully cloned using rapid amplification of cDNA ends cloning. The open reading frame of EcAQP4 is 621 bp, encoding 206 amino acids, with a predicted molecular weight of 21.673 kDa and a theoretical isoelectric point of 8.30; it is a hydrophobic protein with five transmembrane structural domains. The open reading frame of EcAQP11 is 783 bp, encoding 260 amino acids, with a predicted molecular weight of 28.490 kDa and a theoretical isoelectric point of 5.40; it is a hydrophobic protein with four transmembrane domains. In sequence alignment, AQP4 in E. carinicauda shared the highest homology with that in Macrobrachium rosenbergii (94.63%), while AQP11 in E. carinicauda shared the highest homology with that in Penaeus monodon (81.47%). Furthermore, RNA interference was used for silencing EcAQP4 and EcAQP11 expression to verify their function. In carbonate alkalinity stress, the mortality of E. carinicauda increased significantly following RNA interference. At 72 h, mortality reached 45% and 55% in the EcAQP4 and EcAQP11 groups, respectively, being significantly higher than that in the control group. The blood osmotic pressure of E. carinicauda in the EcAQP4 group was significantly higher than that in the control group. Similarly, the blood osmotic pressure of E. carinicauda in the EcAQP11 group was significantly increased. In summary, aquaporins play important roles in regulating osmotic pressure and maintaining ion balance in response to alkalinity stress in E. carinicauda.
