Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, Fujian, 361021, China.
State Key Laboratory of Large Yellow Croaker Breeding, Ningde, Fujian, 352000, China.
Fish Shellfish Immunol. 2018 Oct;81:121-129. doi: 10.1016/j.fsi.2018.06.051. Epub 2018 Jul 10.
Pseudomonas plecoglossicida is a threatening and important pathogen in aquaculture and causes heavy losses. Expression of L321_RS19110 was found significant up-regulated at 18 °C than at 28 °C, which was confirmed by quantitative real-time PCR. RNAi significantly reduced the content of L321_RS19110 mRNA of P. plecoglossicida, and exhibited the best efficiency of gene silencing with a reduction of 84.9%. Compared with the wild type strain, the infection of L321_RS19110-RNAi-1 strain resulted in the onset time delay, and 30% reduction in mortality of Epinephelus coioides, as well as alleviates in the symptoms of E. coioides spleen. Moreover, compared with wild type strain, the gene silence of L321_RS19110 in P. plecoglossicida resulted in a significant change in transcriptome of infected E. coioides. The results of KEGG analysis showed that genes of chemokine signaling pathway and cytokine-cytokine receptor interaction, digestion and absorption of proteins (non-specific immune) and antigen processing and presentation pathways were most affected by L321_RS19110-RNAi of P. plecoglossicida. In these immune pathways, the most affected immune genes were associated with different number of non-coding RNAs. Among them, most lncRNAs and miRNAs exerted negative regulation on immune genes. The results indicated that L321_RS19110 was an important virulent gene of P. plecoglossicida, the up-regulation of the immune pathways made E. coioides more likely to remove L321_RS19110-RNAi strain than the wild type strain of P. plecoglossicida, the expression of immune genes were regulated by miRNA and lncRNA in a complex way.
迟缓爱德华氏菌是水产养殖中一种具有威胁性且重要的病原体，可导致严重损失。研究发现，L321_RS19110 在 18°C 时的表达水平显著高于 28°C，实时定量 PCR 进一步证实了这一点。RNAi 显著降低了迟缓爱德华氏菌 L321_RS19110 mRNA 的含量，基因沉默效率最高可达 84.9%。与野生型菌株相比，L321_RS19110-RNAi-1 菌株感染导致卵形鲳鲹发病时间延迟，死亡率降低 30%，卵形鲳鲹脾脏症状减轻。此外，与野生型菌株相比，迟缓爱德华氏菌 L321_RS19110 的基因沉默导致感染卵形鲳鲹的转录组发生显著变化。KEGG 分析结果表明，趋化因子信号通路和细胞因子-细胞因子受体相互作用、蛋白质消化吸收（非特异性免疫）和抗原加工呈递途径的基因受迟缓爱德华氏菌 L321_RS19110-RNAi 的影响最大。在这些免疫途径中，受影响最大的免疫基因与不同数量的非编码 RNA 有关。其中，大多数 lncRNA 和 miRNA 对免疫基因起负调控作用。结果表明，L321_RS19110 是迟缓爱德华氏菌的一个重要毒力基因，免疫途径的上调使卵形鲳鲹更有可能清除 L321_RS19110-RNAi 菌株，而不是迟缓爱德华氏菌野生型菌株，免疫基因的表达受到 miRNA 和 lncRNA 的复杂调控。
