Key Laboratory of Science and Technology for Aquaculture and Food Safety of Fujian Province University, Fisheries college/Fisheries Biotechnology Institute, Jimei University, Xiamen 361021, China.
Fish Shellfish Immunol. 2010 Mar;28(3):453-60. doi: 10.1016/j.fsi.2009.12.002. Epub 2009 Dec 22.
The importance of the nitric oxide synthase (NOS) gene family is demonstrated by many studies in recent years. However, the lack of sequence information and clones of shrimp NOS cDNA limits further study on its characterization and function in this species. In this report, the cDNA of NOS contained full-length ORF was cloned from the Pacific white shrimp, Litopenaeus vannamei. It was of 4680 bp, including a 5'-terminal untranslated region (UTR) of 278 bp, a 3'-terminal UTR of 862 bp, which contained 5 ATTTA repeats, and an open reading frame (ORF) of 3540 bp encoding a polypeptide of 1179 amino acids. It contained a typical NO synthase domain at the N-terminal, next to a flavodoxin 1 domain, a flavin adenine dinucleotide (FAD) binding domain, respectively, and a conservative nicotinamide adenine dinucleotide (NAD) binding domain structure at the C-terminal. Quantitative real-time reverse transcription PCR analysis revealed L. vannamei NOS (LvNOS) to be expressed in most shrimp tissues, with highest expression in the hepatopancreas and weakest expression in skin. The expression of LvNOS after challenge with LPS and poly I:C was tested in hemocytes, hepatopancreas and nerve. The results indicated that the NOS transcript level could be induced in hemocytes by injection with LPS. The highest expression was in the hemocyte, with 8.8 times (at 3 h) as much as that in the control (p < 0.05). However, sharp down-regulation of NOS was found in hepatopancreas and nerve after LPS and poly I:C injection (p < 0.05). These results suggested that NOS might play an important role in shrimp's defense against pathogenic infection.
近年来的许多研究表明，一氧化氮合酶（NOS）基因家族非常重要。然而，由于缺乏虾类 NOS cDNA 的序列信息和克隆，限制了对其在该物种中的特征和功能的进一步研究。本研究报告从凡纳滨对虾（Litopenaeus vannamei）中克隆到包含全长 ORF 的 NOS cDNA。它的 cDNA 长 4680bp，包含 5'端非翻译区（UTR）278bp、3'端 UTR862bp，其中含有 5 个 ATTTA 重复序列，以及编码 1179 个氨基酸的开放阅读框（ORF）3540bp。它在 N 端包含一个典型的 NOS 结构域，紧接着是一个黄素蛋白 1 结构域、黄素腺嘌呤二核苷酸（FAD）结合结构域，以及 C 端保守的烟酰胺腺嘌呤二核苷酸（NAD）结合结构域结构。定量实时 RT-PCR 分析显示，LvNOS 在凡纳滨对虾的大多数组织中均有表达，在肝胰腺中的表达最高，在皮肤中的表达最弱。在血细胞、肝胰腺和神经中检测了 LPS 和 poly I:C 刺激后 LvNOS 的表达。结果表明，注射 LPS 可诱导血细胞中 NOS 转录物水平升高。在注射 LPS 后 3 小时，血细胞中的表达量最高，是对照组的 8.8 倍（p<0.05）。然而，在注射 LPS 和 poly I:C 后，肝胰腺和神经中的 NOS 表达明显下调（p<0.05）。这些结果表明，NOS 可能在虾类防御病原体感染中发挥重要作用。
