嗜水气单胞菌感染翘嘴鳜头肾转录组分析

Transcriptomic analysis of the head kidney of Siniperca chuatsi infected with Aeromonas hydrophila

中文关键词: 翘嘴鳜  嗜水气单胞菌  转录组  差异表达基因

英文关键词: Siniperca chuatsi  Aeromonas hydrophila  Transcriptome  Different expression gene

中文摘要:

      嗜水气单胞菌(Aeromonas hydrophila)是严重危害翘嘴鳜(Siniperca chuatsi)养殖生产的主要病原之一，为揭示嗜水气单胞菌感染翘嘴鳜后宿主基因表达水平的变化，筛选免疫相关基因，解析翘嘴鳜应答病原细菌感染的分子机制，本研究以病原嗜水气单胞菌感染翘嘴鳜，于感染24 h后，采集感染组与对照组翘嘴鳜头肾组织，采用Illumina Hiseq 2000进行了RNA-Seq分析，原始数据拼接后组装共获得53 040个单基因(unigene)。基因差异表达分析结果显示，感染组和未感染组翘嘴鳜存在526个差异表达基因，包括254个上调基因和272个下调基因，其中，免疫相关的显著上调的差异基因主要有炎症和免疫原性细胞因子白介素、补体系统、MHCⅠ型抗原提呈、溶菌酶、丝氨酸蛋白酶抑制因子、泛素蛋白连接酶等。GO富集分析发现，差异基因主要涉及免疫应答反应和炎症反应等，经KEGG富集分析显示，89个通路富集显著，免疫相关的代谢通路主要有内吞作用和吞噬体等。此外，实时荧光定量PCR验证结果表明，所选取7个差异表达免疫相关基因与RNA-seq结果具有相似的表达趋势。本研究为揭示翘嘴鳜对病原微生物感染的防御分子机制奠定了理论基础。

英文摘要:

      Aeromonas hydrophila is one of the main pathogens seriously endangering mandarin fish farming and production. In order to explore the changes in host gene expression levels in A. hydrophila infection, screen for immune-related genes, and analyze the molecular mechanism of Siniperca chuatsi infected with Aeromonas hydrophila in response to pathogenic bacterial infection. The head kidney tissues of the infected and control groups were collected 24 h after inoculation and used for mRNA extraction, and transcriptome sequencing was performed using high-throughput sequencing technology. A total of 53 040 single genes (unigenes) were obtained from the original sequencing data through de novo assembly. The results of gene differential expression analysis showed that there were 526 differentially expressed genes, of which 254 were upregulated and 272 were down-regulated in the infected and control groups. Among the differentially expressed genes, several key genes involved in the immune response, such as interleukin-8, interleukin-6 receptor, interleukin 17 receptor, lysozyme, complement receptor type 1, antigen processing and presentation, serine protease inhibitor, and E3 ubiquitin-protein ligase were present. Gene ontology analysis revealed that the different genes were mainly involved in immune response and inflammation. A KEGG analysis showed that there were 89 significantly enriched and immune-related metabolic pathways mainly involved with endocytosis and phagosomes. Real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) verification was performed on seven DEGs, and the results showed that RT-qPCR was consistent with RNA-Seq analysis. These results lay a theoretical foundation for a follow-up study of gene function and in-depth exploration of the molecular defense mechanism of S. chuatsi against pathogenic microorganism infection.