Liu Hong-tao, Wang Jun, Mao Yong, Liu Min, Niu Su-fang, Qiao Ying, Su Yong-quan, Wang Chun-zhong, Zheng Zhi-peng
State Key Laboratory of Marine Environmental Sciences (Xiamen University), Xiamen, 361102, Fujian, China.
State Key Laboratory of Marine Environmental Sciences (Xiamen University), Xiamen, 361102, Fujian, China.
Fish Shellfish Immunol. 2015 Dec;47(2):817-23. doi: 10.1016/j.fsi.2015.09.044. Epub 2015 Oct 9.
Antimicrobial peptides (AMPs) are important components of the innate immune system and function as the first line of defense against invading pathogens. In current study we identified, cloned and characterized a novel stylicin AMP from Kuruma shrimp Marsupenaeus japonicus (Mj-sty). The full-length cDNA of Mj-sty was 428 bp with an open reading frame of 315 bp that encoded 104 amino acids. The theoretical molecular mass of mature Mj-sty was 8.693 kDa with an isoelectric point (pI) of 4.79. A proline-rich N-terminal region and a C-terminal region contained 13 cysteine residues were identified. Genomic sequence analysis with respect to its cDNA showed that Mj-sty was organized into two exons interrupted by one intron. Tissue-specific expression revealed that Mj-sty was mainly transcribed in gills and hemocytes. Expression of Mj-sty in early developmental stages demonstrated that Mj-sty mRNA were present from fertilized eggs to post-larvae of 17 days (PL17), and the expression levels showed a significant variation in different developmental stages. After challenge of white spot syndrome virus (WSSV), the time-dependent expression pattern of Mj-sty in both gills and hepatopancrease showed down-regulation at the early hours of infection, subsequently up-regulation and down-regulation, and then up-regulation at the end hours to almost the half of the controls. The results indicate that Mj-sty is potentially involved in the ontogenesis and immune responses against WSSV.
抗菌肽（AMPs）是先天免疫系统的重要组成部分，作为抵御入侵病原体的第一道防线发挥作用。在当前研究中，我们从日本对虾（Marsupenaeus japonicus）中鉴定、克隆并表征了一种新型的抗菌肽stylicin（Mj-sty）。Mj-sty的全长cDNA为428 bp，开放阅读框为315 bp，编码104个氨基酸。成熟Mj-sty的理论分子量为8.693 kDa，等电点（pI）为4.79。鉴定出一个富含脯氨酸的N端区域和一个含有13个半胱氨酸残基的C端区域。对其cDNA进行基因组序列分析表明，Mj-sty由两个外显子组成，中间被一个内含子打断。组织特异性表达显示，Mj-sty主要在鳃和血细胞中转录。Mj-sty在早期发育阶段的表达表明，从受精卵到17日龄后期幼体（PL17）都存在Mj-sty mRNA，并且表达水平在不同发育阶段有显著差异。在感染白斑综合征病毒（WSSV）后，Mj-sty在鳃和肝胰腺中的时间依赖性表达模式显示，在感染早期数小时下调，随后上调和下调，然后在感染后期数小时上调至几乎是对照的一半。结果表明，Mj-sty可能参与了对WSSV的个体发育和免疫反应。
