) are a family of ubiquitous proteins that minimize the harmful effects of oxidative stress by catalyzing the reduction of hydrogen peroxide (H₂O₂) and organic hydroperoxides to less harmful forms. A full-length cDNA corresponding to a 2-Cys Macrobrachium nipponense and designated as (GenBank accession no. KC866353). The full-length cDNA was 998 bp, containing a 72 bp 5′ untranslated region (UTR), a 212 bp 3′UTR with a poly (A) tail, and a 594 bp open reading frame (ORF) encoding a polypeptide of 198 amino acids with a molecular mass of protein possesses two conserved cysteine residues that play an essential role in the antioxidant activity of this proteins. The protein, as deduced from the cDNA sequence, has a high level (87%) of sequence similarity to the 2-Cys gene was expressed in the ovary, hepatopancreas, muscle, heart, testis, and intestines, with expression being highest in the hepatopancreas. mRNA expression was significantly higher in the hepatopancreas and gill of prawns exposed to hypoxia (12 and 24 h) and reoxygenation (6 h) stress than in the control group. This suggests a possible role in alleviatingoxidative stress by increasing mRNA expression in response to environmental hypoxia and reoxygenation.