大黄鱼TLR25的分子结构及表达特征分析  

Molecular Structure and Expression Characterizations of TLR25 in Large Yellow Croaker,Larimichthys crocea

作　　者：李永健 姚翠鸾[1] LI Yongjian;YAO Cuiluan(Fisheries College,Jimei University,Xiamen 361021,China)

机构地区：[1]集美大学水产学院,福建厦门361021

出　　处：《集美大学学报（自然科学版）》2023年第2期106-114,共9页Journal of Jimei University：Natural Science

基　　金：福建省重大专项(2020NZ08003)。

摘　　要：克隆了大黄鱼TLR25(LcTLR25)基因的cDNA序列,采用荧光定量PCR检测了LcTLR25基因在大黄鱼不同组织中的表达,以及免疫诱导后的表达变化。结果显示:LcTLR25 cDNA序列长度为2868 bp,包含1605 bp的开放阅读框,编码534个氨基酸;预测蛋白质由5个LRR结构域、1个跨膜区和1个TIR结构域组成,主要定位于细胞膜;系统进化树分析表明,LcTLR25与其他硬骨鱼的TLR25基因聚为一支,与尼罗罗非鱼的TLR25序列同源性最高;定量PCR分析显示,LcTLR25在大黄鱼肠组织中表达量最高,但是在鳃、肝、胃及皮肤组织中未检测到其表达;LPS刺激后,大黄鱼LCK细胞系中LcTLR25基因表达量显著增加,在刺激后6 h达到最高值(P<0.05),随后逐渐恢复至对照组水平;而LcTLR25在Poly I:C刺激后6 h显著下降(P<0.05),随后逐渐恢复至对照水平。提示LcTLR25可能参与LPS诱导的免疫反应。In the present study,the cDNA sequence of a TLR 25 from large yellow croaker(Larimichthys crocea)was cloned and the expression of LcTLR 25 transcripts in different tissues was detected by qPCR as well as in LCK cells stimulated with LPS or Poly I:C.Our results showed that a 2868 bp fragment represented LcTLR 25 was obtained by homologous cloning,containing a 1605 bp open reading frame(ORF)and encoding 534 amino acids.The predicted Lc TLR25 protein included five LRR domains,a transmembrane region and a TIR domain,which belonged to the conservative TLR family.Phylogenetic tree analysis showed that LcTLR 25 was clustered to the teleost TLR1 subfamily and TLR25 clade,and shared the highest sequence identity with TLR25 from Nile tilapia(Oreochromis niloticus).The qPCR analysis revealed that LcTLR 25 expressed most in intestine,but it was not detected in gill,liver,stomach and skin.After LPS challenge,the expression levels of LcTLR 25 in LCK cell increased significantly(P<0.05),reaching the peak value of 3 times as much as the control at 6 h post-stimulation.However,it decreased significantly after Poly I:C stimulation(P<0.05),with the lowest value appearing at 6 h post-challenge.These results suggested that LcTLR 25 might be induced largely by LPS challenge.

关 键 词：大黄鱼 TLR25基因 克隆 转录表达 免疫刺激 

分 类 号：S917.4[农业科学—水产科学]