洪湖碘泡虫在发病和隐性感染异育银鲫组织器官中的分布  

Tissue tropism of Myxobolus honghuensis in diseased and asymptomatic gibel carp(Carassius auratus gibelio)

作　　者：杨坤 翟凯旋 习丙文[1,2] 陈凯[2] 谢骏[2] YANG Kun;ZHAI Kaixuan;XI Bingwen;CHEN Kai;XIE Jun(Wuxi Fishery College,Nanjing Agricultural University,Wuxi 214081,China;Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization,Ministry of Agriculture and Rural Affairs,Freshwater Fisheries Research Center,Chinese Academy of Fishery Sciences,Wuxi 214081,China)

机构地区：[1]南京农业大学无锡渔业学院,江苏无锡214081 [2]中国水产科学研究院淡水渔业研究中心,农业农村部淡水渔业和种质资源利用重点实验室,江苏无锡214081

出　　处：《水产学报》2022年第6期1085-1093,共9页Journal of Fisheries of China

基　　金：财政部和农业农村部-国家现代农业产业技术体系(CARS-45);国家自然科学基金(32073019)。

摘　　要：为探究洪湖碘泡虫在被感染异育银鲫不同组织器官中的分布及不同感染阶段的差异,实验采用显微镜镜检、PCR检测及组织病理切片相结合手段,对发病及隐性感染异育银鲫的肌肉、伪鳃、鳃、头肾等11个组织器官进行了广泛检测分析。显微镜镜检发现,在发病鱼的咽、伪鳃和鳃能观察到孢囊或成熟孢子;在隐性感染异育银鲫的咽上壁与副蝶骨间结缔组织、伪鳃及其血管周边观察到大量棕黄色结节,并含有洪湖碘泡虫的成熟孢子。不同组织器官DNA样品PCR检测发现,在发病鱼除肌肉外的其他10个组织器官中均检测到洪湖碘泡虫存在,其中伪鳃检出率最高(100%);隐性感染异育银鲫在咽上壁组织、伪鳃、头肾、体肾、脾脏及卵巢中检出洪湖碘泡虫,伪鳃检出率也为最高(26.7%)。组织病理切片显示,发病鱼咽上壁内分布着大量蜂巢状孢囊及成熟孢子,伪鳃被严重侵占和破坏;残存伪鳃鳃丝周边能观察到增殖和发育阶段的孢子生成细胞。综上所述,本研究首次报道了洪湖碘泡虫在发病和隐性感染异育银鲫不同组织器官中的分布差异,发现伪鳃可能是洪湖碘泡虫寄生和发育成熟的重要器官。结果为洪湖碘泡虫病的准确检验检疫和进一步开展致病机制研究奠定基础。The pharyngeal myxosporidiosis caused by Myxobolus honghuensis is one of the most severe parasitic diseases in the culture of Carassius auratus gibelio.In order to reveal the tissue distribution and differences of M.honghuensis in the diseased and asymptomatic C.auratus gibelio.This study has collected and examined the muscle,pseudobranch,gills,head kidney and other 11 organs by microscopic,one-tube semi-nest PCR and histopathological section.Microscopical exam showed that the sporocyst and mature spores were most detected in the pharynx,pseudobranch and gills of diseased fish,while the mature spores were enclosed with yellow nodal and most detected from pseudobranch and first efferent branchial artery in the asymptomatic gibel carp.PCR results showed M.honghuensis could be detected in most of the tested organs in diseased fish except muscle,and pseudobranch had the highest infection rate(100%).In asymptomatic C.auratus gibelio,positive results were detected in pharynx,pseudobranch,head kidney,kidney,spleen and ovary,and the highest infection rate(26.7%)also was from the pseudobranch.Tissue sections of the diseased C.auratus gibelio showed M.honghuensis forming numbers of sporocysts between the pharynx wall and skull,and some near the pharyngobranchials.The pseudobranch was seriously destructed by the sporscysts,and the sporogonic cells of M.honghuensis could be observed near the left pseudobranch filament.Based on the microscopic exam and PCR test,this study firstly found that the pseudobranch may be the main parasitic and sporogonic site of M.honghuensis,and revealed the infection variation of M.honghuensis between the diseased and asymptomatic C.auratus gibelio.

关 键 词：异育银鲫 洪湖碘泡虫 喉孢子虫病 伪鳃 单管半巢式PCR法 组织分布 

分 类 号：S941.5[农业科学—水产养殖]