In this study, the sequence of TGF-β1 was obtained.An open reading frame is composed of 1143 nucleotides, which enco-ded a precursor protein consisted of 377 amino acids, and its molecular weight is 43 kDa, the isoelectric point is 8.72.Its N-terminal 19 residues are the signal peptides , and the C-terminal 112 residues are the mature peptide , whose molecular weight is 12.5 kDa.Se-quence alignment showed that sweetfish TGF-β1 shared the highest homology with rainbow trout , the leader peptide was 72%, and the mature peptide was 93%.In healthy sweetfish , TGF-β1 was expressed in the all tested tissues , and that the highest expression was in the kidney .After Listonella anguillarum infection , sweetfish TGF-β1 mRNAs were up-regulated in all detected sweetfish tissues , espe-cially in the kidney.The prokaryotie expression vector pET-28a-TGF-β1 was constructed, and its antiserum was prepared , which can react with the target protein TGF-β1, but it can not react with the bacterial protein itself .The above results showed that sweetfish TGF-β1 expression is related with L.anguillarum infection, and it revealed that TGF-β1 may play a role in the acute phase of fish antibacte-rial immunity.%通过转录组测序的方法，获得香鱼的TGF-β1基因序列，由1134个核苷酸组成，包括一个大的开放阅读框，编码成377个氨基酸组成的前体蛋白，分子量大小为43 kDa，等电点为8.72。 N端前19个氨基酸为信号肽，成熟肽由C末端112个氨基酸组成，分子量大小为12.5 kDa。序列比对表明香鱼与虹鳟同源性最高，前导肽为72％，成熟肽为93％。在健康香鱼中，TGF-β1基因在肝、脾、肾、脑、肌、肠、鳃、心组织中均有表达，在肾组织中表达量最高。鳗利斯顿氏菌侵染香鱼组织后，各组织中的TGF-β1基因mRNA表达量均显著上调，肾组织中变化最为显著，注射12 h时为对照组的14.5倍。构建了原核表达质粒pET-28a-TGF-β1，并制备了多克隆抗血清，能与目的蛋白TGF-β1起特异性反应，但不与细菌蛋白自身反应。以上结果表明，香鱼TGF-β1基因表达变化与鳗利斯顿氏菌的侵染相关，揭示了TGF-β1可能在鱼类抗细菌的急性期免疫应答过程中发挥作用。
展开▼
