Fujian Engineering Research Center of Aquatic Breeding and Healthy Aquaculture, Fisheries College, Jimei University, Xiamen, 361021, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, China.
College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China; Key Laboratory of Marine Biotechnology of Fujian Province, Institute of Oceanology, Fujian Agriculture and Forestry University, Fuzhou, China.
Fish Shellfish Immunol. 2020 Nov;106:384-392. doi: 10.1016/j.fsi.2020.08.009. Epub 2020 Aug 6.
Antimicrobial peptide (AMP) is a crucial component of the innate immune system in crustaceans. In mud crab, Scylla paramamosain, a commercially important species, a glycine-rich antimicrobial peptide (Spgly-AMP) gene was newly identified and putatively encoded a 26aa signal peptide and 37aa mature peptide. To understand the function of Spgly-AMP, the expression profile of Spgly-amp gene was characterized, which showed Spgly-amp was expressed widely in most tissues of adult crabs with the highest expression level in hemocytes. After Vibrio parahaemolyticus, PGN, or Poly I:C stimulations, the expression level of Spgly-amp was significantly up-regulated in the hemocytes. In antimicrobial assays, chemically synthesized Spgly-AMP peptides exhibited strong antibacterial activities against both Gram-positive and Gram-negative bacteria and high thermal stability after high-temperature heating. These findings in the present study verified the importance of the Spgly-AMP in defense of pathogenic bacteria infection in the mud crab and provided a promising candidate of antimicrobial agents in the crab aquaculture.
抗菌肽（AMP）是甲壳动物先天免疫系统的重要组成部分。在泥蟹（Scylla paramamosain）中，一种商业上重要的物种，新鉴定出一种富含甘氨酸的抗菌肽（Spgly-AMP）基因，推测其编码一个 26 个氨基酸的信号肽和 37 个氨基酸的成熟肽。为了了解 Spgly-AMP 的功能，对 Spgly-amp 基因的表达谱进行了表征，结果表明 Spgly-amp 在成年蟹的大多数组织中广泛表达，在血细胞中的表达水平最高。在受到副溶血弧菌、PGN 或 Poly I:C 刺激后，血细胞中 Spgly-amp 的表达水平显著上调。在抗菌测定中，化学合成的 Spgly-AMP 肽对革兰氏阳性和革兰氏阴性细菌均表现出很强的抗菌活性，并且在高温加热后仍具有很高的热稳定性。本研究中的这些发现证实了 Spgly-AMP 在泥蟹防御病原菌感染中的重要性，并为蟹类养殖中的抗菌剂提供了一个有前途的候选物。
