Molecular Characterization of Anion Exchanger 2 in and Its Role in Nitrite Stress.

Anion exchanger 2 (AE2) mediates the Cl/HCO transmembrane exchange process and regulates intracellular pH homeostasis. In this study, the gene (GenBank: PQ073349) was cloned and characterized from using the rapid amplification of cDNA ends (RACE) technique. Employing bioinformatics, real-time fluorescence quantitative PCR, and RNA interference, we explored the gene's sequence characteristics, tissue distribution, and the effects of nitrite on shrimp survival, physiology, and tissue damage following gene silencing. The results showed that AE2 cDNA was 5134 bp in length, encoding 1293 amino acids, which includes both the Band3 and HCO structural domains. was expressed in all tissues, with the highest expression in muscle. After silencing , shrimp survival increased and hemolymph nitrite levels decreased. Notably, the oxidative stress enzyme system was not severely affected, and gill tissue damage was reduced. In addition, the expression level of Na/K/2Cl cotransporter 1 () was significantly reduced ( < 0.05). These findings suggest that AE2 and NKCC1 are jointly involved in regulating the physiological process of nitrite entry into the shrimp body through gill tissue. Overall, this study provides a crucial experimental foundation for addressing the toxicity concerns associated with nitrite.