Chen Mei-Zhen, Chen Jiong, Lu Xin-Jiang, Shi Yu-Hong
Ningbo University, Ningbo 315211, China.
Dongwuxue Yanjiu. 2010 Dec;31(6):595-600. doi: 10.3724/SP.J.1141.2010.06595.
Hepcidin, a member of cysteine-rich antimicrobial peptides, plays an important role in both fish adaptive immunity and the regulation of iron metabolism. In this paper, the nucleotide sequence of a full-length cDNA clone for ayu (Plecoglossus altivelis) hepcidin gene, 763 nucleotides in length, was determined. Ayu hepcidin gene contained a complete open reading frame (ORF) encoding an 85-amino-acid peptide with a molecular weight of 9.7 k. A signal peptide of 24 residues existed in hepcidin N-terminus. The ayu hepcidin mature peptide sequence contained 25 amino acids with eight cysteines that formed four disulfide bonds. Sequence comparison and phylogenetic analysis showed that ayu hepcidin was most similar to Atlantic salmon (Salmo salar), and the relationships of the different hepcidin coincided well with the evolutionary relationships of their organisms. In healthy ayu, hepcidin mRNA was mainly expressed in the liver, spleen, kidney, heart, and muscle. After Listonella anguillarum infection, liver hepcidin mRNA expression change was determined by quantitative real-time PCR (qRT-PCR) method. Hepcidin transcripts of ayu liver were significantly up-regulated and peaked at 12 h. These results suggest that hepcidin may be involved in the immune response of ayu.
铁调素是富含半胱氨酸的抗菌肽家族成员之一，在鱼类适应性免疫和铁代谢调节中均发挥重要作用。本文测定了香鱼（Plecoglossus altivelis）铁调素基因全长cDNA克隆的核苷酸序列，长度为763个核苷酸。香鱼铁调素基因包含一个完整的开放阅读框（ORF），编码一个85个氨基酸的肽段，分子量为9.7k。铁调素N端存在一个24个残基的信号肽。香鱼铁调素成熟肽序列包含25个氨基酸，有8个半胱氨酸，形成4个二硫键。序列比较和系统发育分析表明，香鱼铁调素与大西洋鲑（Salmo salar）最为相似，不同铁调素之间的关系与其生物体的进化关系吻合良好。在健康香鱼中，铁调素mRNA主要在肝脏、脾脏、肾脏、心脏和肌肉中表达。鳗弧菌（Listonella anguillarum）感染后，采用定量实时PCR（qRT-PCR）方法测定肝脏铁调素mRNA表达变化。香鱼肝中铁调素转录本显著上调，并在12小时达到峰值。这些结果表明，铁调素可能参与了香鱼的免疫反应。
