A review of the phylogeny of the Haptophyta
A review of the phylogeny of the Haptophyta
复制标题
定形植物的系统发育回顾
DOI：
--
复制
发表时间：
2004
期刊：
影响因子：
--
通讯作者：
L. Medlin
中科院分区：
文献类型：
--
作者：
A. Sáez;I. Probert;J. Young;B. Edvardsen;W. Eikrem;L. Medlin
大多数附着菌是单细胞的光合鞭毛虫，尽管有些有球形，菌落，变形虫或丝状阶段。几乎所有的都有一个特征性的丝状附属物，即附着丝，位于两个鞭毛之间。我们已经积累了小亚基rRNA基因序列（18 S rDNA）从125个附着体和比对的序列与300多个已发表和未发表的叶绿素a+c藻类。系统发育构建贝叶斯，最小进化和加权最大简约分析。巴夫藻属成员与其余附着植物之间的高度分歧（6%）支持将附着植物门分为两个纲：Prymnesiophyceae和巴夫藻纲（Edvardsen et al. 2000）。在Prymnesiophyceae内的四个主要分支被确定为与已知的分类群相对应：一个分支包括Phaeocystales;第二个包括Prymnesiales的成员;第三个代表Isochryphilales;第四个是Coccolithales。另外两个次要分支包含其序列来自基因克隆文库的分类群。在缺乏与这些序列相关的细胞形态学信息的情况下，我们无法确定它们是否属于现有的订单，或者是否应该建立新的订单。这些分类群与任何已知的培养分类群没有很强的相关性。在18 S rRNA基因分析中，1%至2%的差异证明了高于家族水平的分离。
Most haptophytes are unicellular, photosynthetic flagellates, although some have coccoid, colonial, amoeboid or filamentous stages. Nearly all have a characteristic filamentous appendage, the haptonema, arising between the two flagella. We have amassed small subunit rRNA gene sequences (18S rDNA) from 125 haptophytes and aligned the sequences with those of over 300 published and unpublished chlorophyll a+c algae. Phylogenies were constructed using Bayesian, minimum evolution and weighted maximum parsimony analyses. The high divergence (6%) between members of Pavlova and the remaining haptophytes supports the division of the Haptophyta into two classes: the Prymnesiophyceae and the Pavlovophyceae (Edvardsen et al. 2000). Four major clades within the Prymnesiophyceae were identified that correspond to known taxa: one clade embraces Phaeocystales; the second includes members of the Prymnesiales; the third represents the Isochrysidales; and the fourth the Coccolithales. Two other minor clades contain taxa whose sequences were derived from a gene clone library. In the absence of information on cell morphology associated with these sequences we are unable to determine whether they belong to existing orders or if new orders should be erected. These taxa are not strongly related to any of the known cultured taxa. One to two per cent divergence in the 18S rRNA gene analysis warrants a separation above the level of family.
影响因子：
3.5
作者：
MEDLIN, L;ELWOOD, HJ;SOGIN, ML
通讯作者：
SOGIN, ML