权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Morphology and phylogenetic relationships of the CW group of the unicellnlar green algae

单细胞绿藻CW类群的形态学和系统发育关系

基本信息

批准号：
17570074
负责人：
WATANABE Shin
金额：
$ 1.86万
依托单位：
University of Toyama
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2007
项目状态：
已结题

项目摘要

In the molecular phylogenetic investigation on the terrestrial, unicellular green algae having basal bodies arranged in clockwise orientation, which have been classified in the four orders, it was found that they were included in a monophyletic group (CW group). The morphological characters which have been assumed to be important in classification were evaluated on the basis of the present molecular phylogeny. The tetrad and sarcinoid formations of vegetative cells, which were once considered as features of the order Chlorosarcinales appeared in different clades, and thus, the opinion that these features could not be used for classification at the order rank was supported. Multinucleate conditions of vegetative cells developing with age evolved in different subclades within the CW group. An asteroid chloroplast was found in different clades, and it was pointed that morphological observation for identifying should be careful, because this type of chloroplast is often confused with axile … More and parietal ones. A net-like or sponge-like chloroplast was found in a clade, in which both mutinuleate and uninucleate organisms were included in it's subclades, resulting that these chloroplast types occurred as synapomorphy. The morphological features of zoospores, such as presence or absence of cell wall around cell body, and composition of cell wall layers, were synapomorphy in some subclades. The flagellar lengths, direction of flagella, and compositions of flagellar apparatus were also characters shared in several specified subclades. Accumulation of astaxanthin appeared in two clades as synapomorphy, and organisms having motile and non-motile vegetative cells were included in one of these subclades. In habitats other than soil environment, sea water inhabitants were placed in a monophyletic branch, showing that they secondarily developed from an organism lived in freshwater regions. Unicellular green algae fixing on substrates in freshwater environment were found to evolved in several different phylogenetic lineages. A symbiotic alga within leaves of Lemna trisulca was placed in a branch comprising organisms having similar morphology of vegetative cells and zoospores to this symbiont. Less

在分子系统学研究的陆生，单细胞绿色藻类具有顺时针方向排列的基体，这已被划分为四个目，它被发现，他们被包括在一个单系组（CW组）。在分子系统学研究的基础上，对在分类中起重要作用的形态学特征进行了评价。曾被认为是绿藻目特征的营养细胞四分体和肌氨酸样结构出现在不同的分支中，因此，支持了这些特征不能用于该目等级分类的观点。随着年龄的增长，营养细胞的多核条件在CW组内的不同亚支中进化。在不同的进化枝中发现了一个星状叶绿体，并指出在形态学观察上进行鉴别时应谨慎，因为这种叶绿体常与轴相混淆 ...更多信息还有顶骨的在一个分支中发现了网状或海绵状的叶绿体，其中多核和单核生物都包括在它的亚分支中，导致这些叶绿体类型以突触形态出现。游动孢子的形态特征，如胞体周围细胞壁的有无和细胞壁层的组成，在某些亚支中是共形的。鞭毛长度、方向和鞭毛器的组成也是几个特定亚支共有的特征。积累的虾青素出现在两个进化枝作为synapomorphy，和生物体具有能动和非能动的营养细胞包括在这些亚进化枝之一。在土壤环境以外的生境中，海水生物被置于一个单系分支中，表明它们是从生活在淡水区的生物次级发展而来的。淡水环境中附着在基质上的单细胞绿色藻类被发现进化为几个不同的系统发育谱系。将三沟浮萍叶内的共生体置于一个分支中，该分支包含与该共生体具有相似营养细胞和游动孢子形态的生物体。少