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

本研究的主要目的是在比较超微结构和分子系统发育的基础上，阐明光合作用有机体与复合叶绿体的胞内共生作用与物种多样性的关系。在本项目的第一阶段，根据已发表的资料和本项目的结果，结合它们的亚细胞特性，对建立复合叶绿体及其在真核光合作用生物进化中的意义进行了探讨。其次，以绿藻为研究对象，通过18SrRNA、rbcL和EF-Tu基因同源性的分子系统学分析，推测了绿藻细胞的寄主来源和内共生体的来源。通过对含有复合叶绿体的生物的比较细胞学分析，可以看出它们的特异性…。更多的多样性与寄主和共生体的不同组合密切相关，不同程度地控制着来自共生体和寄主细胞器的遗传新细胞器，不同的Chaces在进化过程中遇到了胞内共生体，通过与光合色素组成的比较，绿藻的质体可能来自原生藻类。然而，从来没有给出过系统发育的证据。基于这一观点，在叶绿素a+b植物中建立了上述3个基因，包括藻类植物、藻类植物、原生植物及其相关生物。因此，叶绿藻的叶绿体可能来源于与苔藓属有关的生物，而不是原生植物，而与真生植物的质体有较高的亲缘关系。另一方面，与18SrRNA不同，绿藻的寄主起源于与真甲藻或尾藻类似的原生动物。较少

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