大菱鲆趋化因子CCL34基因的鉴定及其响应细菌感染的表达特征

Characterization of Chemokine CCL34 in Turbot(Scophthalmus maximus)and Its Expression Analysis in Response to Bacterial Infection

为了研究大菱鲆(Scophthalmus maximus)中趋化因子(Chenokine)的特征及其在大菱鲆免疫过程中发挥的作用,设计了本文中的实验。本实验从大菱鲆基因组和转录组数据库中鉴定了一个硬骨鱼特有的趋化因子CC亚家族成员—CCL34,并选取大菱鲆的8个健康组织以及2种细菌感染后的肠道和皮肤组织,采用实时荧光定量PCR(qRT-PCR)对其表达特征进行研究。序列分析结果显示该趋化因子全长mRNA包含1个327 bp的5’非编码区(UTR),1个246 bp的3’非编码区,和1个编码103个氨基酸残基长度为312 bp的开放阅读框(ORF)。此CCL34基因含有4个外显子和3个内含子。通过系统发育分析、共线性分析,将该大菱鲆趋化因子命名为CCL34。实时荧光定量PCR表明CCL34在大菱鲆健康组织中普遍表达,尤其在肾脏、肝脏、皮肤中有高水平表达。鳗弧菌(Vibrio anguillarum)和无乳链球菌(Streptococcus agalactiae)感染后,肠道组织CCL34基因表达量较对照组显著性上调(p<0.05),这表明CCL34可能在大菱鲆的肠道粘膜免疫中起重要作用。本研究为趋化因子家族功能的研究奠定了基础,为增强鱼类免疫力和抗病能力提供了理论依据。

In order to study the characteristics of chemokine in turbot(Scophthalmus marimus)and its role in the immune process of turbot,the experiment in this paper was designed.In this study,a teleost-specific chemokine CCL34 was identified in turbot(Scophthalmus maximus)through searching genome reference and transcriptome datasets,and its expression patterns were explored in eight healthy tissues,and in intestine and skin after two bacterial infections.Sequence analysis showed that the full-length mRNA includes a 327 bp 5’untranslated region(UTR),a 246 bp 3’untranslated region,and a 312 bp open reading frame(ORF)encoding 103 amino acid residues.The CCL34 gene contains four exons and three introns.Phylogenetic and syntenic analysis indicted that the chemokine was turbot chemokine CCL34.Real-time quantitative PCR(qRT-PCR)showed that the CCL34 was widely expressed in healthy tissues,with high expression levels observed in the kidney,liver and skin.After infection with Vibrio anguillarum and Streptococcus agalactiae,the expression of CCL34 gene in intestinal tissue was significantly up-regulated compared with the control group(p<0.05),indicating that CCL34 may play important roles in mucosal immune activities in turbot.This study set a foundation for the study of the function of chemokine family,and provided a theoretical basis for enhancing fish immunity and disease resistance.