Molecular phylogenetic analyzes and comparative cytology of the origin of compound chloroplasts and eucaryotic photosynthetic organisms with them.

复合叶绿体及其真核光合生物起源的分子系统发育分析和比较细胞学。

基本信息

批准号：
07454232
负责人：
HARA Yoshiaki
金额：
$ 4.61万
依托单位：
Yamagata University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1997
项目状态：
已结题

项目摘要

The main objective of this research project was to elucidate the relation ship of the endocytosymbiosis and species diversity of photosynthetic organism with compound chloroplasts, based on their comparative ultrastructure and molecular phylogeny. At the first of this project, establishing the compound chloroplasts and evolutionary significance of eucaryotic photosynthetic organisms with them were invesitigated following the published information and the results obtained from this project, concernig with their subcellular characteristics. Secondaly, focusing on the chlorarachiophytes which are referred to the evolutionary chimaera with nucleomorphs of the receidure of nuleus of the symbiont, the origins of host and endosymbiont composing of the chlorarachiophyte cell were supposed by molecular phylogentic anayses of 18SrRNA,rbcL and EF-Tu gene homology.As the result obtained from the comparative cytology of the organisms with compound clororplasts, it can be pointed out that their spec … More ies divercity were closely related to the different combination of hosts and symbionts, variable degree controlling genetically new organelles originated from symbiont and host organelles, and different chaces encountered the endocytosymbionses during their evolutionary process.From the comparison with the photosynthetic pigment compositions, chlorarachiophyte plastids would be derived from prasionophycean algae. However, no phylogenetic evidenses heve never been given. Standing on this viewpoint, three genes mentioned above were established among chlorophyll a+b plants, including chorarachniophytes, ulvophytes, prasinophytes and their related organisms. As a results, chloroplasts of chlorarachniophytes would be originated from organisms related with Bryopsis but not from prasinophytes, which was rather related to plasts of euglenophytes. On the other hand, the origin of the host of chlorarachniophytes as ifferred from 18SrRNA was the related protozoa like to euglyphinids or cercomonads. Less

该研究项目的主要目的是基于复合叶绿体的比较超微结构和分子系统发育，阐明光合生物的内吞共生和物种多样性的关系。该项目首先建立了复合叶绿体及其进化意义。根据已发表的信息和该项目获得的结果，对真核光合生物进行了研究，其次关注其亚细胞特征。绿花生植物是具有共生体细胞核核形态的进化嵌合体，通过18SrRNA、rbcL和EF-Tu基因同源性的分子系统发育分析，推测了绿花生植物细胞的宿主起源和内共生体组成。具有复合叶绿体的生物体的比较细胞学结果，可以指出，它们的物种多样性与宿主和共生体的不同组合、不同程度地控制来自共生体和宿主细胞器的遗传新细胞器以及在进化过程中遇到内吞共生体的不同机会密切相关。就光合色素成分而言，绿藻植物质体可能源自拟藻纲藻类，但尚无系统发育证据。站在这个观点上，上述三个基因是在叶绿素a+b植物中建立的，包括藻类植物、草藻类植物及其相关生物，因此，藻类植物的叶绿体可能起源于与羽藻属相关的生物。另一方面，它与裸藻植物的质体相当相关。从 18SrRNA 推断出的氯蛛植物是相关的原生动物，如裸藻类或尾藻类。