大劣按蚊唾腺特异性抗原SG6编码基因的鉴定及表达特征分析  

Identification and expression characteristics of the gene encoding for Anopheles dirus specific salivary antigen SG6

作　　者：冯欣宇[1,2] 周何军 李美[1] 夏志贵[1] FENG Xin-yu;ZHOU He-jun;LI Mei;XIA Zhi-gui(National Institute of Parasitic Diseases,Chinese Center for Disease Control and Prevention/Key Laboratory of Parasite and Vector Biology,National Health and Family Planning Commission/WHO Collaborating Center for Tropical Diseases/National Center for International Research on Tropical Diseases,Shanghai 200025,China;One Health Center,Shanghai Jiaotong University School of Medicine)

机构地区：[1]中国疾病预防控制中心寄生虫病预防控制所,国家卫生健康委员会寄生虫病原与媒介生物学重点实验室,国家热带病研究中心,世界卫生组织热带病合作中心,上海200025 [2]全球健康学院,上海交通大学医学院

出　　处：《中国病原生物学杂志》2021年第2期181-186,共6页Journal of Pathogen Biology

摘　　要：目的鉴定分析大劣按蚊唾腺特异性抗原SG6蛋白编码基因特征。方法从全基因组水平对大劣按蚊SG6基因进行鉴定,应用PCR和RT-PCR鉴定编码蛋白基因,采用生物信息学方法分析该基因及其编码的蛋白分子特征。采用RTIzol法提取大劣按蚊组织RNA,通过实时荧光定量PCR(qRT-PCR)分析其组织体异性表达特征。获取近缘按蚊物种序列,构建系统发育树,进行进化分析。结果SG6基因CDS编码区域全长324 bp,翻译长度107个氨基酸。编码的SG6属于亲水性的非稳定蛋白,且包含一个信号肽和跨膜结构域。二级结构包含α-螺旋(39.3%),延伸链(6.5%),β-折叠(10.3%)和无规则卷曲(43.9%),I-TASSER多线程程序LOMETS显示最优模型为5yfpC。系统发育进化分析发现大劣按蚊SG6与法老按蚊(Anopheles farauti)SG6亲缘关系较近。组织表达分析显示,该基因在大劣按蚊胸部特异性表达。结论我国主要传疟媒介大劣按蚊唾液腺中含有编码SG6蛋白基因,具有特定的表达特征,可作为潜在的评价人蚊接触的流行病学工具。Objective To characterize the gene coding for the SG6 salivary antigen of Anopheles dirus through its structure and expression.Methods An.dirus SG6 was identified via a BLAST search at the genome level and amplification with PCR and RT-PCR.Bioinformatic methods were used to analyze the molecular and biochemical characteristics of SG6.The TRIzol method was used to extract RNA from different tissues,and then real-time fluorescent quantitative PCR(qRT-PCR)was used to analyze the specificity of tissue expression.A phylogenetic tree was constructed by obtaining the sequence of Anopheles mosquitoes’orthologues.Results The CDS region of the SG6 gene was 324 bp in length and encoded 107 amino acids.Analysis indicated that SG6 was a hydrophilic non-stable protein and that it contained a signal peptide and transmembrane domain.Secondary structures included alpha-helices(39.3%),extended strands(6.5%),beta turns(10.3%),and random curls(43.9%).The LOMETS approach with multiple threading programs indicated that the optimal model was 5 yfpC,and 3 D homologous modeling was performed accordingly.Phylogenetic analysis revealed that An.dirus SG6 was closely related to An.farauti SG6.Analysis of tissue expression indicated that the gene was expressed specifically in the thorax of the mosquito.Conclusion This study identified the gene coding for the SG6 salivary antigen of An.dirus and characterized its expression.This gene could be developed into an epidemiological tool with which to evaluate human exposure to mosquitoes.

关 键 词：疟疾 按蚊 大劣 唾腺 基因表达 

分 类 号：R384.1[医药卫生—医学寄生虫学]