棘头梅童鱼肝型脂肪酸结合蛋白基因克隆及组织表达分析

Gene cloning and tissue expression analysis of the liver fatty acid-binding protein gene in Collichthys lucidus

为进一步了解肝型脂肪酸结合蛋白基因(L-FABP基因)在棘头梅童鱼(Collichthys lucidus)营养调控、脂肪酸代谢和免疫应答等方面的功能作用,以棘头梅童鱼全基因组组装数据为基础,获得L-FABP基因的含开放阅读框的cDNA序列,利用生物信息学方法分析编码的蛋白质结构及进化关系,采用荧光定量(qRT-PCR)技术研究了不同组织中L-FABP基因的表达情况。结果表明,L-FABP基因cDNA序列为475 bp,其中5’非翻译区为51 bp,3’非翻译区为40 bp,开放阅读框为384 bp,编码127个氨基酸。其结构由10个β-折叠链和2个α-螺旋链组成,在氨基酸3~126位点间具有保守的脂质/胞质性脂肪酸结合结构域。棘头梅童鱼L-FABP基因与大黄鱼、条纹狼鲈同源性较近,与绿河鲀、尼罗罗非鱼和斑马鱼同源性较远。L-FABP基因在棘头梅童鱼肝脏、肠道、眼、大脑、心脏、肌肉、胃、鳃、脾脏、头肾和中肾中均有表达,其中肝脏中的L-FABP相对表达量最高,显著高于其他组织(P<0.05)。

Based on the whole genome assembly data of Collichthys lucidus,the cDNA sequence containing open reading frame(ORF)of L-FABP gene was obtained.The structure and evolutionary relationship of the encoded protein by bioinformatics methods were analyzed,and the expression of the L-FABP gene in different tissues was studied by the real-time PCR technique.The results showed that the cDNA sequence of L-FABP gene was 475 bp,of which 5’-UTR(untranslated region)was 51 bp,3’-UTR was 40 bp,and ORF was 384 bp,encoding 127 amino acids.Its structure consists of 10β-pleated sheets and twoα-helix with a conserved lipocalin/cytosolic fatty-acid binding domain between amino acid positions 3 and 126.The L-FABP gene of C.lucidus was more closely homologous to Larimichthys crocea,Morone saxatilis,and was more distantly homologous to Tetraodon nigroviridis,Oreochromis niloticus,and Danio rerio.The expression of L-FABP was detected in the liver,intestine,eye,brain,heart,muscle,stomach,gill,spleen,head kidney,and middle kidney of C.lucidus,and the expression level of L-FABP was highest in the liver with significant differences(P<0.05).This study provides an essential reference for further research on the biological properties of liver fatty acid-binding protein and the role of L-FABP gene in lipid metabolism in C.lucidus.