Phylogeny of nuclear-encoded plastid-targeted GAPDH gene supports separate origins for the peridinin- and the fucoxanthin derivative-containing plastids of dinoflagellates.
Phylogeny of nuclear-encoded plastid-targeted GAPDH gene supports separate origins for the peridinin- and the fucoxanthin derivative-containing plastids of dinoflagellates.
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DOI：
10.1078/1434461042650325
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发表时间：
2004-12
期刊：
影响因子：
2.5
通讯作者：
K. Takishita;K. Ishida;T. Maruyama
中科院分区：
文献类型：
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作者：
K. Takishita;K. Ishida;T. Maruyama
虽然大多数光合作用的甲藻都含有附着体，但三个甲藻属Karenia、Karlowdium和Takayama具有异常的有色体，它们含有岩藻黄质及其衍生物(19‘-己酰氧基-岩藻黄质和19’-丁酰氧基-岩藻黄质)而不是岩藻黄质。这种色素成分类似于触生植物的成分。到目前为止，所研究的所有含有周胶的甲藻至少有两种类型的甘油醛-3-磷酸脱氢酶(GAPDH)：胞质和胞质靶向形式。在本研究中，我们从三种含有岩藻黄质衍生物的甲藻中克隆和测序了胞质和胞质靶向GAPDH蛋白的基因。从分子系统发育来看，含藻黄质衍生物的藻类的GAPDH基因与触生藻类的GAPDH基因关系密切，而与含藻附素的藻类没有亲缘关系，而含有藻黄质和褐藻黄质衍生物的藻类的细胞质中的一个与之密切相关。考虑到以前报道的一种理论，即含藻鞭毛虫的胞质GAPDH是在甲藻谱系分裂之前由胞液形式的基因复制而来的，因此很有可能含藻周膜的甲藻的胞质靶基因是该藻类中的原始基因，而在含有岩藻黄质的甲藻中，在第三次内共生过程中，最初的叶绿体靶基因被触藻内共生体的GAPDH所取代。目前的结果有力地支持了这一假设，即含有附着素和岩藻黄质衍生物的甲藻的质体来自不同的来源。
Although most photosynthetic dinoflagellates have plastids with peridinin, the three dinoflagellate genera Karenia, Karlodinium, and Takayama possess anomalously pigmented plastids that contain fucoxanthin and its derivatives (19'-hexanoyloxy-fucoxanthin and 19'-butanoyloxy-fucoxanthin) instead of the peridinin. This pigment composition is similar to that of haptophytes. All peridinin-containing dinoflagellates investigated so far have at least two types of glyceraldehyde-3-phosphate dehydrogenase (GAPDH): cytosolic and plastid-targeted forms. In the present study, we cloned and sequenced genes encoding cytosolic and plastid-targeted GAPDH proteins from three species of the fucoxanthin derivative-containing dinoflagellates. Based on the molecular phylogeny, the plastid-targeted GAPDH genes of the fucoxanthin derivative-containing dinoflagellates were closely related to those of haptophyte algae rather than to the peridinin-containing dinoflagellates, while one of several cytosolic versions from the peridinin- and the fucoxanthin derivative-containing dinoflagellates are closely related to each other. Considering a previously reported theory that the plastid-targeted GAPDH from the peridinin-containing dinoflagellates originated by a gene duplication of the cytosolic form before the splitting of the dinoflagellate lineage, it is highly likely that the plastid-targeted GAPDH gene of the peridinin-containing dinoflagellates is original in this algal group and that in the fucoxanthin-containing dinoflagellates, the original plastid-targeted GAPDH was replaced by that of a haptophyte endosymbiont during a tertiary endosymbiosis. The present results strongly support the hypothesis that the plastids of the peridinin- and the fucoxanthin derivative-containing dinoflagellates are of separate origin.