Analyses of factors controlling infection and development of fish-infecting myxosporeans

鱼类感染粘孢子虫感染及发育控制因素分析

• 批准号: 15580159
• 负责人: YOKOYAMA Hiroshi
• 金额: $ 1.66万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15580159/
• 关键词: Myxosporean; Mucus; Lectin; Emaciation disease; Fish parasite; 放線胞子虫; 体表粘液; サクラマス

It has been reported that actinospores, the infective stage of myxosporeans (mainly freshwater species), release the sporoplasms in contact with fish skin mucus and then initiate the invasion into fish hosts. Recently, fish-to-fish transmission of Enteromyxum leei from the intestine of marine fishes has been demonstrated. Therefore, in the present study, I aimed to clarify the characteristics of fish mucus inducing sporoplasm release of freshwater actinospores, and to evaluate the infectivity and the attachment ability of marine myxosporean trophozoites to fish intestinal mucus.Sporoplasm release of actinospores of Myxobiolus areticus infecting salmonid fishes was investigated in relation to skin mucus. Skin mucus from masu salmon (a susceptible fish) stimulated sporoplasm releases dose-dependently ; percentage of sporoplasm release reached 60 % at 1.0 mg-protein/ml. On the other hand, in non-susceptible fishes, percentages of sporoplasm release were 37 % and 20 % in sockeye salmon and goldfish, respectively. It was also shown that several commercial lectins (Con A, etc.) prohibited but some (RCA I, etc.) activated sporoplasm release of actinospores, suggesting the involvement of sugars in chemoreception of actinospores. Further, isolated sporoplasms of actinospores successfully transmitted naive fish by an intrapentoneal injection.Morphological and molecular analyses showed that a myxosporean from the intestine of tiger puffer is identified as E.leei. PCR for detection of E.leei was developed. No difference was observed in attachment to intestinal mucus and susceptibility among marine fish species, indicating that E.leei has a broad host range.It is concluded that fish mucus (from skin or intestine) plays an important role in the invasion of myxosporeans, and that sugar-lectin interaction is one of the factors controlling myxosporean infection.

据报道，放线孢子是粘孢子虫(主要是淡水物种)的感染阶段，它会释放出与鱼皮肤粘液接触的孢子体，然后启动对鱼类宿主的入侵。最近，从海水鱼的肠道传播李氏肠粘菌被证明是鱼对鱼的传播。因此，本研究旨在阐明鱼类粘液诱导淡水放线孢子释放孢子质的特性，并评价海洋粘孢子虫滋养体对鱼肠道粘液的侵染性和附着能力。马哈鱼皮肤粘液以剂量依赖方式刺激孢子体释放，1.0 mg蛋白/ml时孢子体释放百分率达60%，而非敏感鱼类的孢子质释放百分率分别为37%和20%。还发现了几种商业凝集素(Con A等)禁止，但有些(RCA I等)激活放线孢子的孢子质释放，暗示糖参与了放线孢子的化学接受。此外，分离到的放线孢子孢子体通过五孔注射成功地传播了幼稚的鱼类。形态和分子分析表明，从虎河豚肠道中分离到的一种粘孢子虫被鉴定为E.leei。建立了检测E.leei的聚合酶链式反应方法。不同种海水鱼对肠道粘液的黏附性和敏感性无明显差异，表明李氏艾美耳球虫具有广泛的寄主范围。结论：鱼粘液(来自皮肤或肠道)在粘孢子虫入侵过程中起重要作用，糖-凝集素相互作用是控制粘孢子虫感染的因素之一。

项目成果

Development of a PCR-based method for the detection of the enteric myxozoans causing the emaciation disease of cultured tiger puffer.

开发基于 PCR 的方法来检测引起养殖虎河豚消瘦病的肠道粘液虫。

• 发表时间: 2005
• 期刊: Fish Pathology 40(印刷中)
• 作者: Yanagida T.;M.A.Freeman;Y.Nomura;I.Takami;Y.Sugihara;H.Yokoyama;K.Ogawa
• 通讯作者: K.Ogawa

魚類に寄生する粘液胞子虫の生活環と起源

寄生在鱼类上的粘孢子虫的生命周期和起源

• 发表时间: 2003
• 期刊: 原生動物学雑誌 37
• 作者: Yanagida T.;Y.Nomura;T.Kimura;Y.Fukuda;H.Yokoyama;K.Ogawa;横山 博
• 通讯作者: 横山 博

Molecular and morphological redescriptions of enteric myxozoans, Enteromyxum leei(formerly Myxidium sp. TP) and Enteromyxum fugu comb.n.(syn.Myxidium fugu) from cultured tiger puffer.

来自养殖虎河豚的肠粘液动物、Enteromyxum leei（以前称为 Myxidium sp. TP）和 Enteromyxum fugu Comb.n.（syn.Myxidium fugu）的分子和形态学重新描述。

• 发表时间: 2004
• 期刊: Fish Pathology 39・3
• 作者: Yanagida T.;Y.Nomura;T.Kimura;Y.Fukuda;H.Yokoyama;K.Ogawa
• 通讯作者: K.Ogawa

Development of a PCR-based assay for the detection of enteric myxozoans causing the emaciation disease of cultured tiger puffer.

开发基于 PCR 的检测方法，用于检测引起养殖虎河豚消瘦病的肠道粘液虫。

• 发表时间: 2005
• 期刊: Fish Pathology 40・1(印刷中)
• 作者: Yanagida T.;M.A.Freeman;Y.Nomura;I.Takami;Y.Sugihara;H.Yokoyama;K.Ogawa
• 通讯作者: K.Ogawa

Molecular and morphological redescriptions of enteric myxozoans, Enteromyxum leei (formerly Myxidium sp.TP) and Enteromyxum fugu comb.n.(syn.Myxidium fugu) from cultured tiger puffer.

来自养殖虎河豚的肠粘液动物、Enteromyxum leei（以前称为 Myxidium sp.TP）和 Enteromyxum fugu Comb.n.（syn.Myxidium fugu）的分子和形态学重新描述。

• 发表时间: 2004
• 期刊: Fish Pathology 39
• 作者: Yanagida T.;Y.Nomura;T.Kimura;Y.Fukuda;H.Yokoyama;K.Ogawa
• 通讯作者: K.Ogawa