布氏鲳鲹超氧化物歧化酶基因的序列分析及组织分布

Sequence Analysis and Tissue Distribution of Superoxide Dismutase Gene in Snubnose Pompane(Trachinotus blochii)

超氧化物歧化酶(SOD)是通过歧化反应催化超氧化物转化为O_(2)和H_(2)O_(2)的酶,铜锌超氧化物歧化酶(CuZnSOD)和锰超氧化物歧化酶(MnSOD)是两种主要存在形式。本研究通过RACE法和RT-qPCR技术对布氏鲳鲹(Trachinotus blochii)的SOD-1、SOD-2进行基因克隆、序列分析和组织分布的研究。结果显示,布氏鲳鲹SOD-1(icCuZnSOD)基因的ORF长486 bp,编码161个氨基酸,分子量为16.676 kD,蛋白结构预测无信号肽,含有1个SOD-CU结构域。布氏鲳鲹SOD-2(mMnSOD)基因的ORF长657 bp,编码218个氨基酸,分子量为24.261 k D,蛋白结构预测无信号肽,含有1个SOD-FE蛋白结构域。氨基酸序列同源比对结果表明,布氏鲳鲹SOD-1有1段与其他鱼类显著差异的精氨酸-天冬酰胺-丝氨酸-丙氨酸-半胱氨酸-谷氨酰胺-异亮氨酸序列,且与鲈形目点带石斑鱼(Epinephelus coioides)、斜带石斑鱼(Epinephelus malabaricus)CuZnSOD同源性较高;SOD-2与鲈形目的红甘鲹(Seriola dumerili)MnSOD同源性较高且聚为一支。组织分布结果表明,SOD-1和SOD-2在布氏鲳鲹的心脏和肝脏中表达量最高,其次在脑和鳃表达量相对较高,表明SOD-1和SOD-2可能在免疫反应和维持新陈代谢方面有重要作用。本研究为今后布氏鲳鲹的抗逆、免疫的研究提供了研究依据。

Superoxide dismutases(SOD)are some enzymes that catalyze superoxide to oxygen(O_(2))and hydrogen peroxide(H_(2)O_(2))by disproportionation.There are two types of CuZnSOD and MnSOD in cells.In this study,the cloning and tissue distribution of icCuZnSOD(SOD-1)and(SOD-2)in Trachinotus blochii were studied by RACE and RT-qPCR.The studies showed that the ORF of SOD-1(icCuZnSOD)was 486 bp and encoded 161 amino acids with a molecular weight of 16.676 kD,and SOD-1 had no signal peptide but had a SOD-CU protein domain.The ORF of SOD-2(mMnSOD)was 657 bp and encoded 218 amino acids with a molecular weight of 24.261 kD,and SOD-2 also had no signal peptide with a SOD-FE protein domain.By homologous alignment of amino acid sequences,a different peptide fragment was found in SOD-1 that contains Arg-Asn-Ser-Ala-Cys-Gln-Ile.It was found that SOD-1 was closely related to Epinephelus coioides and Epinephelus malabaricus,and SOD-2 was closely related to Seriola dumerili and forms its own branch.Real-time quantitative PCR showed that the expression of SOD-1 and SOD-2 was the highest in the heart and liver,followed by relatively high expression in the brain and gill.It indicated that SOD-1 and SOD-2 may be involved in immune epidemic prevention and maintaining metabolism.This study lays a theoretical foundation for the study of the stress resistance and immune of Trachinostus blochii in the future.