State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; Key Laboratory of Mariculture and Stock Enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian 262306, China.
Key Laboratory of Mariculture and Stock Enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian 262306, China.
Fish Shellfish Immunol. 2018 Mar;74:559-566. doi: 10.1016/j.fsi.2018.01.004. Epub 2018 Jan 6.
Multiple functions of caspases include normal cell turnover, proper development and function of the immune system, hormone-dependent atrophy, embryonic development and chemical-induced cell injury. During artificial propagation of Pacific cod, Gadus macrocephalus, high mortality occurred during early development stages. Here, we performed various analyses on the cDNA and protein sequences of six different G. macrocephalus caspases namely GmCasp3, 6, 7, 8, 9 and 10, and tried to investigate the contributions of caspase family to the development and Nervous Necrosis Virus (NNV) resistance. Sequence analysis of GmCaspase proteins showed that each caspase shared conserved domains like "HG", "QACXG (X for R, G or Q)" and "GSWF" except GmCasp10. Sequence alignment and phylogenetic tree showed that GmCasp8 and GmCasp10 were quite different from those of other fishes. 3-D models indicated that structure of GmCasp3 is very conservative, but GmCasp6, 7, 8, 9 and 10 are less conservative. Tissue distribution analysis showed that six Gmcaspases mRNA transcripts were detected in tissues of intestine, gill, thymus, head-kidney and spleen with different abundance, but Gmcasp7 were not detected in the brain. GmCasp3 transcript was kept at very low level in the early development stages, while the expression levels of GmCasp6, 7, 8, 10 were different at various development stages. GmCasp8 level seemed to be much higher than other caspases in the heads of 65dph and 75dph juveniles. To understand the role of caspases during NNV outbreak, modulation in expression of each Gmcaspases were investigated. The results showed that GmCasp3 transcript level increased significantly when NNV broke out, while GmCasp7, 8, 9 and 10 in cod heads decreased obviously at 69dph and 77dph. The results suggest that caspases in Pacific cod should be diverse in their structure and function, and their unique features and response to NNV outbreak add more evidences for the specificity of immune system in Pacific cod.
多聚半胱氨酸天冬氨酸蛋白酶（caspases）的多种功能包括正常细胞更新、免疫系统的正常发育和功能、激素依赖性萎缩、胚胎发育和化学诱导的细胞损伤。在太平洋鳕鱼（Gadus macrocephalus）的人工繁殖过程中，幼鱼在早期发育阶段死亡率很高。在这里，我们对 6 种不同的太平洋鳕鱼 caspase 即 GmCasp3、6、7、8、9 和 10 的 cDNA 和蛋白质序列进行了各种分析，并试图研究 caspase 家族对发育和神经坏死病毒（NNV）抗性的贡献。GmCaspase 蛋白的序列分析表明，除了 GmCasp10 之外，每个半胱天冬酶都共享保守结构域，如“HG”、“QACXG（X 代表 R、G 或 Q）”和“GSWF”。序列比对和系统发育树表明，GmCasp8 和 GmCasp10 与其他鱼类的差异很大。3-D 模型表明，GmCasp3 的结构非常保守，但 GmCasp6、7、8、9 和 10 则不那么保守。组织分布分析表明，6 种 Gmcaspase mRNA 转录本在肠道、鳃、胸腺、头肾和脾脏等组织中均有检测到，丰度不同，但在脑中未检测到 Gmcasp7。GmCasp3 转录本在早期发育阶段保持在非常低的水平，而 GmCasp6、7、8、10 的表达水平在不同的发育阶段则不同。在 65dph 和 75dph 幼鱼的头部，GmCasp8 的水平似乎明显高于其他半胱天冬酶。为了了解 caspase 在 NNV 爆发期间的作用，我们研究了每种 Gmcaspase 的表达变化。结果表明，当 NNV 爆发时，GmCasp3 转录本水平显著增加，而 cod 头部的 GmCasp7、8、9 和 10 在 69dph 和 77dph 时明显下降。这些结果表明，太平洋鳕鱼中的半胱天冬酶在结构和功能上应该是多样化的，它们的独特特征和对 NNV 爆发的反应为太平洋鳕鱼免疫系统的特异性提供了更多证据。
