大黄鱼凝血酶原类似基因的克隆及其表达分析

采用快速末端cDNA扩增法,首次从大黄鱼中克隆到全长为2 023 bp的凝血酶原类似基因cDNA,编码为617个氨基酸,其中包括80 bp的5′末端非编码区及89 bp包含poly(A)尾的3′末端非编码区。预测1~15位的氨基酸处存在1个信号肽。推导的氨基酸序列与哺乳动物及其他鱼类进行同源性比较,发现其与红鳍东方鲀有73%同源性,而与哺乳动物的同源性为50%~65%。凝血酶原类似基因虽然在大黄鱼的各个组织中组成型表达,但是在减毒鳗弧菌免疫的大黄鱼的脾脏和肾脏中表达明显上调,这表明凝血酶可能参与大黄鱼对细菌侵染的免疫应答。

Molecular Cloning and Expression Analysis of Prothrombin-Like Gene from Large Yellow Croaker (Pseudosciaena crocea)

One prothrombin-like gene is cloned for the first time from large yellow croaker (Pseudosciaena crocea) by utilizing rapid amplification of eDNA ends (RACE).The full-length cDNA of prothrombin-like gene is 2 023 bp encoding a protein of 617 amino acids, with 80 bp 5'-untranslated region and a 3t-untranslated region of 89 bp including poly(A).A signal peptide between 1-15 amino acids has been detected in the predicted prothrombin-like gene.The deduced protein is highly homologous to that of mammalian and fish thrombin and shares 73% sequence identity to that of Fugu rubripes and 50%-65% sequence identity to that of various mammals.The expression of prothrombin-like gene is obviously upregulated in spleen and kidney after immunization with live attenuated vibrio, anguillarum strain, although it is also constitutively expressed in liver, gills, brain, gill and skin, suggesting that thrombin may be involved in the immune response to bacterial challenge in large yellow croaker.