State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, 361005, China; Guangdong Yuequn Ocean Biological Reaearch Development Co., Ltd., Jieyang, 522000, China.
State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, 361005, China.
Fish Shellfish Immunol. 2018 Apr;75:109-114. doi: 10.1016/j.fsi.2018.01.028. Epub 2018 Feb 2.
Larimichthys crocea, the special marine economy fish, owns the largest annual yield for a single species in China. One of the most significant factors affecting large yellow croaker culture is the diseases, especially the threat of marine white spot disease which caused by a protozoan Cryptocaryon irritans. Antimicrobial peptides (AMPs) have been demonstrated to be active against bacterium, fungi and parasites, showing their potential usefulness in aquaculture as substitutes for antibiotics. Many researches have been carried out about the AMPs concentrating on the activity resist on C. irritans, and piscidin-like of L. crocea owning widely antibacterial spectrum and strong activity against C. irritans was screened in our team. In the paper, taking advantage of the large yellow croaker hepatic comparison transcriptome in response to C. irritans at 3d post infection, seven kinds of AMPs have been excavated from the differently expressed genes, including LEAP2 like, LEAP-2A, hepcidin, hepcidin-like, piscidin-5-like, piscidin-5-like type 4 and bactericidal permeability increasing protein (BPI). Hepcidin, hepcidin-like, piscidin-5-like, piscidin-5-like type4 and BPI were up-regulated to protect large yellow croaker from being damaged by C. irritans infection; while LEAP2 like and LEAP-2A were down-regulated, they might be as a negative-feedback regulation factor or some other regulatory mechanisms to adjust the immune response in the process of C. irritans infection. The differential expression changes were verified with quantitative real-time PCR (qRT-PCR) to illustrate the reliability of the sequenced data. Hearteningly, piscidin-5-like type 4 was a novel type which was high similar to other piscidin-5-like types. Interestingly, the infection may well cause alternative splicing of LEAP-2A mRNA, which was a surprised phenomenon and finding after C. irritans infection, but more further study was needed to be conducted. Therefore, the data showed that these AMPs were involved in the immune response to the C. irritans infection. In all, these results implied that the immune response of AMPs to C. irritans infection was a complex and sophisticated regulatory process.
大黄鱼，一种特殊的海洋经济鱼类，是中国单种产量最大的鱼类。影响大黄鱼养殖的最重要因素之一是疾病，特别是由原生动物刺激隐核虫引起的海洋白点病的威胁。抗菌肽（AMPs）已被证明对细菌、真菌和寄生虫具有活性，显示出它们在水产养殖中作为抗生素替代品的潜在用途。许多研究都集中在 AMPs 对刺激隐核虫的活性抵抗上，我们团队筛选出了大黄鱼的鱼杀菌肽样物，它具有广泛的抗菌谱和对刺激隐核虫的强活性。在本文中，利用大黄鱼肝在感染刺激隐核虫后 3d 的比较转录组，从差异表达基因中挖掘出 7 种 AMPs，包括 LEAP2 样、LEAP-2A、hepcidin、hepcidin 样、鱼杀菌肽-5 样、鱼杀菌肽-5 样 4 型和杀菌通透性增加蛋白（BPI）。Hepcidin、hepcidin 样、鱼杀菌肽-5 样、鱼杀菌肽-5 样 4 型和 BPI 上调以保护大黄鱼免受刺激隐核虫感染的损害；而 LEAP2 样和 LEAP-2A 下调，它们可能作为负反馈调节因子或其他一些调节机制来调节刺激隐核虫感染过程中的免疫反应。用实时定量 PCR（qRT-PCR）验证了差异表达变化，以说明测序数据的可靠性。令人振奋的是，鱼杀菌肽-5 样 4 型是一种新型的与其他鱼杀菌肽-5 样高度相似的类型。有趣的是，感染可能导致 LEAP-2A mRNA 的选择性剪接，这是刺激隐核虫感染后的一个令人惊讶的现象和发现，但需要进一步研究。因此，这些数据表明，这些 AMPs 参与了对刺激隐核虫感染的免疫反应。总之，这些结果表明，AMP 对刺激隐核虫感染的免疫反应是一个复杂而精细的调节过程。
