Investigation of the prototype organisms of the chromophytes.

一般认为，在绿色植物中，高度多样的细胞超微结构，包括鞭毛器结构是其早期进化多样化的反映。本研究从细胞结构和分子基础上研究了许多金藻，包括新的海洋种、赭单藻和肉核藻，以寻找这些金藻的原型生物，因为它们被认为是异孔蒂的祖先种群。鞭毛器的绝对构型和其它细胞超微结构的分析表明：1）Sarcinochryphilales目（sensu Gayral et Billard 1977）可能是一个人工分类单元，由两个单系类群组成，一个与大洋藻类直接相关，另一个与褐藻和黄绿藻密切相关; 2）一新种，双体磺鞭金藻（Sulcochrysis biplastida），可能是起源于大洋藻纲、狭义Sarcinochryalesensustricto、盘藻纲和网柄藻纲的祖先生物的后代; 3）另一个新种-微小棕单胞菌（Phaeomonasparva）是最原始的异鞭毛藻之一。18 SrRNA部分序列的比较支持这一观点。

It is generally believed in green plants that highly diverse ultrastructure of the cell including flagellar apparatus architecture is a reflection of their early evolutionary diversification. In this study we investigated many chrysophytes, including new marine species, ochromonadalean and sarcinochrysidalean algae on their cell structures and molecular basis to find out the prototype organisms of the chromophytes, since they have been believed to be an ancestral stock of heterokontes. Analysis of absolute configuration of the flagellar apparatus and other cell ultrastructure suggested that, 1) the order Sarcinochrysidales (sensu Gayral et Billard 1977) is probably an artificial taxon and consists of two monophyletic groups, one is directly linked to the pelagophycean algae and the other is closely related to the brown and yellowgreen algae, 2) a new species, Sulcochrysis biplastida, is a possible descendant of ancestral organisms that gave rise to the Pelagophyceae, Sarcinochrysidales sensu stricto, Pedinellophyceae and Dictyochophyceae, 3) another new species, Phaeomonas parva, is one of the most primitive heterokonts. The comparison of partial sequence data of the 18S rRNA suported it.