STUDIES OF BIODIVERSITY ON PROTOZOAN ENDOSYMBIOTIC DIATOMS

原生动物内共生硅藻生物多样性研究

基本信息

批准号：
10836008
负责人：
MAYAMA Shigeki
金额：
$ 1.73万
依托单位：
Tokyo Gakugei University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10836008/
关键词：
Endosymbiont radiolaria forminifera diatoms biodiversity Minutocellus Pelagophyceae marine plankton Nannochloropsis

项目摘要

Endosymbiotic diatoms were isolated from radiolarian and foraminiferan hosts and cultured. Diatoms identified were Nitzschia sp., Entomoneis sp. Nanofrustulum shiloi from benthic larger foraminifera, Sorites orbiculus, and Amphora roettgeri from planktonic foraminifera, Globigerina sp. Endosymbiotic diatom from Sphaerozoum fuscum was Minutocellus polymorphus and observed in detail with transmission and scanning electron microscopy. It was clarified in the analysis of 18S rDNA, that M. polymorphs formed monophyly with Cymatosira and Papilocellulus, which are morphological members of Cymatosiraceae, Symbiotic alga isolated from another Globigerina sp. was cultured and examined by TEM. It was coccoid Pelagophyceae and similar to Pelagococcus subviridis in cellural fien structure but to Pelagococcus calceolata in the analyses of 18S rDNA.We explored transformation route of algae to radiolarian cell inside. Radiolarian species of Spumellaria and Nassellaria were studied regarding relative size to endosymbionts, presence or absence of the opening of radiolarian shell and the size of the opening. Moreover, the diversity of distom flora along the Japan Current flowing from tropical sea area was studied, since it is important for the source of symbionts. Shikine Island and Ryukyu Islands were chosen as study area an researches were performed over two years.

从放射虫和有孔虫宿主中分离并培养内共生硅藻。鉴定出的硅藻为 Nitzschia sp.、Entomoneis sp.。 Nanofrustulum shiloi 来自底栖较大有孔虫、Sorites Orbiculus，以及来自浮游有孔虫 Globigerina sp 的 Amphora roettgeri。来自 Sphaerozoum fuscum 的内共生硅藻是 Minutocellus polymorphus，并通过透射和扫描电子显微镜进行了详细观察。 18S rDNA 分析表明，M. polymorphs 与 Cymatosira 和 Papilocellulus 形成单系，它们是从另一种 Globigerina sp 中分离出来的共生藻 Cymatosiraceae 的形态成员。培养并通过 TEM 检查。其细胞结构与Pelagophyceae相似，18S rDNA分析与Pelagophyceae相似，但18S rDNA分析与Pelagococcus calceolata相似。我们探索了藻类向放射虫细胞内部转化的途径。研究了 Spumellaria 和 Nassellaria 的放射虫种类与内共生体的相对大小、放射虫壳是否存在开口以及开口的大小。此外，还研究了从热带海域流出的日本洋流沿岸的远端植物群的多样性，因为它对于共生体的来源很重要。选择式根岛和琉球群岛作为研究区域，进行了两年多的研究。