Host recognition and mechanism of settlement of monogenean hatching larvae infecting fish

感染鱼类的单殖孵化幼虫的寄主识别及沉降机制

基本信息

批准号：
09460083
负责人：
OGAWA Kazuo
金额：
$ 5.82万
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 (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

项目摘要

Monogenean hatching larvae (oncomiracidia) settle down on the surface of fish host after they recognize some particular substance(s) present on fish body surface. However, nothing has been characterized about it. Following experiments were done to elucidate substances inducing larval settlement and. to purify them.1. A new method has been developed to assay in vitro the settlement-inducing activity in the fish body surface epithelium extracts, using low host-specific Neobenedenia girellae and Seriola-specific Benedenia seriolae. In this assay method, there were almost no differences in the activity among fish species tested, and the activity was heat tolerant. The activity against Heterobothrium okamotoi oncomiracidium was higher in mucus from tiger puffer, the natural host, than those in mucus from unnatural hosts.2. It was shown that the activity was inhibited by specific lectins : WGA against N.girellae and Con A against B.seriolae. It is suggested that substances to induce oncomira … More cidial settlement are sugar-related ones like glycoproteins or polysaccharides.3. H.okamotoi oncomiracidia started to feed blood immediately after settlement on the gills of tiger puffer, while they showed little or no ability to absorb and/or digest blood from unnatural hosts like grass puffer, Japanese flounder or red sea bream, and eventually came off from them.4. Using the in vitro assay an attempt was made to purify N.girellae oncomiracidium settlement-inducing substances extracted from body surface epithelium of Japanese flounder. They were solubilized in anion exchange resin at 0.2-0.3M NaCl, and had a molecular size above the exclusion limit by gel filtration.5. Manifestation of monogenean host specificity involves the ability to recognize host by hatching larvae upon settlement, ability to absorb nutrition from host, ability to be tolerant of host defense mechanisms, etc. It is suggested that benedeniid and polyopisthocotylean monogeneans have different levels in these abilities, and that host specificity is manifested by different factors in different groups of monogeneans. Less

单基因孵化幼虫（Oncomiracidia）在鱼体表面上识别出某些特定物质后，将其固定在鱼类宿主的表面上。但是，没有任何特征。进行实验以阐明物质引起的幼虫设置。净化它们1。已经开发了一种新的方法，可以在体外使用低宿主特异性的新近脑膜和塞利奥拉特异性的贝内尼尼亚血清中的宿主特异性新近脑膜化的植物表面上皮提取物中的设置诱导活性。在这种测定方法中，测试的鱼类的活性几乎没有差异，并且活性是耐热的。天然宿主老虎河豚（Tiger Puffer）的粘液中，针对俄克拉托省异神经的活性比不自然宿主的粘液中的活性高。2。结果表明，该活性受到特定讲座的抑制：对n. girellae和con a con A contion a contion a seriolae。有人建议诱导Oncomira的物质……更多的平民环境是与糖有关的物质，例如糖蛋白或多糖。3。 H.okamotoi oncomiracidia在放在老虎河豚的g上后立即喂血，而它们几乎没有或根本没有吸收和/或没有从草pe，日本地板或红色海胸部等非自然宿主吸收血液的能力，最终从中脱离。4。使用体外测定法，试图净化n.girellae oncomiracidium设置诱导的物质，这些物质从日本落地的身体表面上皮中提取。它们以0.2-0.3m的NaCl溶于阴离子交换树脂，并且分子大小高于凝胶过滤的排除极限5。单基因宿主特异性的表现涉及能够通过在设置后孵化幼虫来识别宿主的能力，从宿主中吸收营养，能够耐受宿主防御机制等能力等。建议在这些能力中具有不同的宿主特异性在不同因素中具有不同因素的不同因素。较少的