大黄鱼REL基因在鳗弧菌侵染后的表达变化分析

Analysis of Expression Changes of Rel Gene of Larimichthys crocea after Infection by Vibrio Anguillarum

REL基因作为NF-kB家族基因的一员,既参与先天性免疫应答,又在适应性免疫应答过程起作用。本研究从大黄鱼中鉴定出NF-kB家族中的REL基因,结果表明,REL基因由611个核苷酸组成,编码204个氨基酸,预测的等电点为6.58,理论分子量为69.153 kDa。谷氨酰胺(9.0%),天冬酰胺(8.5%),脯氨酸和丝氨酸含量相同(7.7%),这四种是整条肽链中发现的最丰富的氨基酸残基。氨基酸序列多重比对表明大黄鱼REL基因具有该家族特征性序列;而进化树关系显示,大黄鱼REL基因的编码蛋白序列同牙鲆相似性较高。荧光定量PCR检测结果显示健康大黄鱼REL基因在肝、脑和鳃中高表达,脾中少量表达。经鳗弧菌感染后,REL基因在0~24 h内,脾和肾表达量逐步升高,脾的表达量在24 h左右到达其峰值,然后在24 h以后逐渐回落并趋于稳定。而在肝脏中,感染12 h以后,其表达量逐渐回落。综上所述,大黄鱼REL基因表达与病原菌感染密切相关,推测其在先天免疫系统中扮演了重要角色,为研究大黄鱼NF-kB家族基因提供了基础资料。

As a member of the NF-kB family of genes,the REL gene is involved in both the innate immune response and the adaptive immune response process.In this study,the REL gene in the NF-kB family was identified from the large yellow croaker Larimichthys crocea.The results showed that the REL gene consisted of 611 nucleotides encoding 204 amino acids with a predicted isoelectric point of 6.58.The theoretical molecular weight is 69.153 kDa.Glutamine(9.0%),asparagine(8.5%),and valine and serine are the same(7.7%),which are the most abundant amino acid residues found in the entire peptide chain.Multiple alignment of amino acid sequences indicated that the REL gene of L.croaker had the characteristic sequence of this family;and the phylogenetic tree relationship showed that the encoded protein sequence of REL gene of L.croaker was similar to that of dentate Paralichtys olivaceus.The results of real-time PCR showed that the REL gene of healthy L.croaker was highly expressed in liver,brain and sputum,and a small amount was expressed in the spleen.After infection with Vibrio anguillarum,the expression of spleen and kidney was gradually increased within 0-24 h,and the expression level of spleen reached its peak value in about 24 h,and then gradually fell back and stabilized after 24 h.In the liver,after 12 h of infection,its expression gradually declined.In summary,the expression of REL gene in large yellow croaker is closely related to pathogen infection,which is presumed to play an important role in the innate immune system,providing basic data for studying the NF-kB family genes of L.croaker.