鸡Foxp3结构预测及组织表达谱分析

Analysis of the structure of chicken Foxp3 and its expression profile in tissues

摘要:

本研究旨在克隆鸡foxp3 (chfoxp3)基因全长编码区序列(coding sequence,CDS)，并对其进行生物信息学及组织表达谱分析。以50日龄无特定病原鸡为样本，从脾脏组织中克隆chfoxp3基因全长CDS序列，利用在线工具和软件对chFoxp3进行生物信息学分析，以实时荧光定量PCR (quantitative real-time PCR,qRT-PCR)技术检测chfoxp3基因在鸡各组织中的表达分布情况。研究结果表明，chfoxp3基因包含882 bp的开放阅读框，编码293个氨基酸，chFoxp3分子质量为33.44 kDa，属于亲水蛋白；chFoxp3具有Fox转录因子家族典型的forkhead结构域，含有核定位信号；其二级结构由α-螺旋(29.35%)、延伸链(10.92%)、β-转角(5.12%)和无规则卷曲(54.61%)组成；chfoxp3在不同组织中表达有差异，在鸡心脏及胰腺中表达水平较高，显著高于脾脏、法氏囊以及胸腺等免疫器官(P<0.01)，这一特点明显区别于哺乳动物；通过系统进化树分析发现，鸡Foxp3与其他野禽属于相同分支，但与哺乳动物相差较远。这些研究结果为进一步深入研究chFoxp3的免疫调节功能奠定了基础。

Abstract:

In this study, we cloned the complete coding sequence (CDS) of chicken foxp3 (chfoxp3) gene, analyzed its structure, and investigated its expression profile in different chicken tissues. To be specific, chfoxp3 was cloned from the splenic tissue of 50-day-old specific-pathogen-free chickens, and analyzed by using online bioinformatics tools or software. The expression profiles of the chfoxp3 gene in different chicken tissues were detected by quantitative real-time PCR (qRT-PCR). The results indicated that the chfoxp3 gene contains an 882-bp open reading frame, encoding 293 amino acids hydrophilic protein with a molecular weight of 33.44 kDa. The chFoxp3 protein has a forkhead domain and carries a nuclear localization signal, which is typical in the Fox transcription factor family. The secondary structure of chFoxp3 consists of α-helix (29.35%), extended chain (10.92%), β-turn (5.12%) and random coil (54.61%). The expression of chfoxp3 varied in different tissues. The expression levels of chfoxp3 in chicken heart and pancreas were higher than in spleen, bursa of Fabricius, thymus, and other immune organs (P<0.01), which was quite different from that of mammals. Phylogenetic tree analysis showed that chFoxp3 belonged to the same clade as other wild birds did, but was far different from that of mammals. These results may facilitate further research on the role of chFoxp3 in immune regulation.