Glutathione S-transferases (GSTs) are important enzymes involved in phase II detoxification and function by conjugating with the thiol group of glutathione. In this study, we isolated an omega class GST from the big-belly seahorse (Hippocampus abdominalis; HaGSTO1) to study the putative xenobiotic responses and defense ability against viral and bacterial infections in this animal. The isolated HaGSTO1 gene, with a cording sequence of 720 bp, encodes a peptide of 239 amino acids. The predicted molecular mass and theoretical isoelectric point of HaGSTO1 was 27.47 kDa and 8.13, respectively. In-silico analysis of HaGSTO1 revealed a characteristic N-terminal thioredoxin-like domain and a C-terminal domain. Unlike other GSTs, the C-terminal of HaGSTO1 reached up to the N-terminal, and the N-terminal functional group was cysteine rather than tyrosine or serine, as observed in other GSTs. Phylogenetic analysis showed the evolutionary proximity of HaGSTO1 with other identified vertebrate and invertebrate GST orthologs. For the first time, we demonstrated the viral defense capability of HaGSTO1 against viral hemorrhagic septicemia virus (VHSV) infection. All six nucleoproteins of VHSV were significantly downregulated in HaGSTO1-overexpressing FHM cells at 24 h after infection compared with those in the control. Moreover, arsenic toxicity was significantly reduced in HaGSTO1-overexpressing FHM cells, and cell viability increased. Real-time polymerase chain reaction analysis showed that HaGSTO1 transcripts were highly expressed in the pouch and gill when compared with those in other tissues. Blood HaGSTO1 transcripts were significantly upregulated after Edwardsiella tarda, Streptococcus iniae, lipopolysaccharide, and polyinosinic:polycytidylic acid challenge experiments. Collectively, these findings suggest the involvement of HaGSTO1 in the host defense mechanism of seahorses.

谷胱甘肽S-转移酶（GSTs）是重要的酶，与谷胱甘肽的巯基结合，参与II期排毒和功能。在这项研究中，我们分离的欧米茄类商品及服务税从膨腹海马（海马腹; HaGSTO1）研究针对这种动物病毒和细菌感染的假定外源性反应和防御能力。分离的HaGSTO1基因具有720 bp的编码序列，编码239个氨基酸的肽。HaGSTO1的预测分子量和理论等电点分别为27.47 kDa和8.13。硅内HaGSTO1的分析揭示了特征性的N端硫氧还蛋白样结构域和C端结构域。与其他GST不同，HaGSTO1的C末端达到N末端，N末端官能团是半胱氨酸而不是酪氨酸或丝氨酸，正如在其他GST中观察到的那样。系统发育分析表明，HaGSTO1与其他已鉴定的脊椎动物和无脊椎动物GST直系同源物进化接近。首次，我们证明了HaGSTO1对病毒性出血性败血病病毒（VHSV）感染的病毒防御能力。与对照组相比，在感染后24 h，过表达HaGSTO1的FHM细胞中VHSV的所有6种核蛋白均显着下调。此外，在过表达HaGSTO1的FHM细胞中，砷毒性显着降低，并且细胞活力提高。与其他组织相比，HaGSTO1转录本在小袋和g中高表达。迟缓爱德华氏菌，链球菌，脂多糖和多肌苷酸：聚胞苷酸攻击实验后，血液HaGSTO1转录物显着上调。这些发现共同表明，HaGSTO1参与了海马的宿主防御机制。