小瓜虫对虹鳟组织病理变化及TLR信号通路基因表达影响  

Histopathological Changes and Gene Expression Dynamics of TLR Signaling Pathway in Oncorhynchus mykiss Infected with Ichthyophthirius multifiliis

作　　者：卢军浩 李兰兰 权金强 赵桂研 孙军 蒋常平 刘哲[1] LU Jun-Hao;LI Lan-Lan;QUAN Jin-Qiang;ZHAO Gui-Yan;SUN Jun;JIANG Chang-Ping;LIU Zhe(College of Animal Science and Technology,Gansu Agricultural University,Lanzhou 730070,China)

机构地区：[1]甘肃农业大学动物科学技术学院,兰州730070

出　　处：《农业生物技术学报》2022年第4期739-750,共12页Journal of Agricultural Biotechnology

基　　金：甘肃省农业农村厅专项(GARS-TSYZ-1);2021年现代丝路寒旱农业科技支撑计划(GSLK-2021-16)。

摘　　要：小瓜虫病病原体为多子小瓜虫(Ichthyophthirius multifiliis),具有高发病率和高死亡率,且缺乏有效的治疗手段,对水产养殖业构成了巨大威胁。本研究旨在观察虹鳟(Oncorhynchus mykiss)感染多子小瓜虫后鳃和皮肤的组织病理学变化,并揭示虹鳟Toll样受体(Toll-like receptor,TLR)信号通路在多子小瓜虫感染后的免疫作用。通过组织切片和扫描电镜对感染多子小瓜虫的虹鳟(处理组)和健康虹鳟(对照组)的鳃和皮肤进行观察,并采用qPCR检测TLR信号通路中TLR2、TLR3、TLR4基因以及肿瘤坏死因子α(tumor necrosis factor-α,TNF-α)、白介素-1β(interleukin-1β,IL-1β)、干扰素-γ(interferon-γ,IFN-γ)基因在鳃、皮肤、肝脏、头肾、脾脏、肠道中的表达动态。结果表明,小瓜虫寄生严重损伤皮肤和鳃的结构,皮肤表面有大量不规则分泌物,表皮与真皮层出现空隙,空隙间寄生了大小不等的小瓜虫滋养体;鳃丝受损脱落,鳃小片变形扭曲,鳃丝小骨肿胀变形;与对照组相比,处理组TLR2在鳃和皮肤中表达量显著升高,分别是对照组的17.19倍和30.57倍(P<0.05),在脾脏中表达量显著降低(P<0.05),是对照组的0.65倍,在其他组织中无显著性差异;TLR3基因在鳃、皮肤、脾脏和肠道中表达量显著升高(P<0.05),分别是对照组的3.8倍、14.09倍、1.66倍和1.89倍,在肝脏和头肾中无显著性差异(P>0.05);TLR4基因在皮肤中表达量显著升高(P<0.05),为对照组的2.24倍,在肝脏和鳃中的表达量显著降低(P<0.05),是对照组的0.36倍和0.22倍,在其他组织中无显著性差异(P>0.05)。与对照组相比,处理组TNF-α基因在鳃、皮肤和头肾中表达量显著升高(P<0.05),IL-1β和IFN-γ基因在本研究所有组织中均显著升高(P<0.05),TNF-α在皮肤中的表达量最高为对照组的8.22倍,IL-1β在头肾中的表达量最高为对照组的14.6倍,IFN-γ在肠道中的表达量最高为对照组的5.1倍。小瓜虫感染对鳃和皮肤造成�The Ichthyophthirius multifiliis has high incidence and high mortality,and lacks effective treatment.It poses a great threat to the aquaculture breeding industry.To observe the infection of Ichthyophthirius multifiliis in rainbow trout(Oncorhynchus mykiss),the gill and skin of rainbow trout(treatment group and control group)were observed by tissue section and scanning electron microscope,and the dynamic expression of Toll-like recepotor(TLR)signaling pathway TLR2,TLR3,TLR4 genes and cytokines tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β),interferon-γ(IFN-γ)genes in gill,skin,liver,head kidney,spleen and intestine were detected by qPCR method.The results showed that the structure of skin and gill were seriously damaged by I.multifiliis.There were a large number of irregular secretions on the skin surface.There were gaps between epidermis and dermis,and the trophozoites of different sizes were parasitic in the gaps.The gill filament was damaged and shed,the gill lamellae were deformed and twisted,and the gill filament bone was swollen and deformed.Compared with the control group,TLR2 gene expression in the treatment group was significantly higher in gill and skin by 17.19 and 30.57 times(P<0.05),and significantly lower in spleen by 0.65 times than the control group,with no significant difference in other tissues.The expression of TLR3 gene in gill,skin,spleen and intestine was significantly increased(P<0.05)and were 3.8,14.09,1.66 and 1.89 times higher than those in the control group,respectively,and there was no significant difference in liver and head kidney(P>0.05);TLR4 gene expression was significantly higher in the skin by 2.24 times and lower in the liver and gill by 0.36 and 0.22 times than in the control group(P<0.05).There was no significant difference in other tissues(P>0.05).Compared with the control group,the treatment group expression of TNF-αin gill,skin and head kidney increased significantly,IL-1βand IFN-γwere significantly increased in all tissues in this study.The expression of TNF

关 键 词：虹鳟 多子小瓜虫 组织病理 Toll样受体(TLR)信号通路 基因表达 

分 类 号：S941.514[农业科学—水产养殖]