Molecular Identification of Algal Endosymbionts in Large Miliolid Foraminifera: 2. Dinoflagellates
Molecular Identification of Algal Endosymbionts in Large Miliolid Foraminifera: 2. Dinoflagellates
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大型粟粒有孔虫中藻类内共生体的分子鉴定：2.甲藻
DOI：
10.1111/j.1550-7408.2001.tb00326.x
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
John J. Lee
中科院分区：
文献类型：
--
作者：
J. Pawłowski;M. Holzmann;J. Fahrni;X. Pochon;John J. Lee
摘要大型粟粒有孔虫Soritinae亚科的共生甲藻形态相似的“共生甲藻”复合体，常见于珊瑚和其他海洋无脊椎动物的物种。Soritid有孔虫在珊瑚礁中非常丰富，有人提出它们与其他带甲藻的珊瑚礁居民共享共生体。为了验证这一假设，我们分析了部分大亚基核糖体DNA序列的甲藻共生体从28有孔虫标本，并比较它们的相应序列的Symbiodinium样内共生体从各组无脊椎动物。系统发育分析表明，所有soritid共生体属于“共生”的物种复合体，其中他们形成7个不同的分子类型（Fr 1-Fr 7）。只有一种类型（Fr 1）在一组无脊椎动物共生体中分支，以前被描述为C型。其余六种类型与先前设计为类型B、C和D的珊瑚共生体形成姐妹群。我们的数据表明，高的遗传多样性和特异性的共生孢子虫类共生体。除了C型，我们没有发现证据的共生体之间的传输有孔虫和其他共生无脊椎动物从同一地点。然而，交流必须经常发生在Soritinae的不同物种之间，缺乏宿主特异性和共生体分布中观察到的一些地理模式。我们的数据表明，Soritinae的亚科成员获得他们的共生体在其历史上至少有三次，每次收购后的快速多样化和独立辐射的共生体内的有孔虫宿主。
Abstract Large miliolid foraminifers of the subfamily Soritinae bear symbiotic dinoflagellates morphologically similar to the species of the “Symbiodinium” complex, commonly found in corals and other marine invertebrates. Soritid foraminifers are abundant in coral reefs and it has been proposed that they share their symbionts with other dinoflagellate-bearing reef dwellers. In order to test this hypothesis, we have analysed partial large subunit ribosomal DNA sequences from dinoflagellates symbionts obtained from 28 foraminiferal specimens, and compared them to the corresponding sequences of Symbiodinium-like endosymbionts from various groups of invertebrates. Phylogenetic analysis of our data shows that all soritid symbionts belong to the “Symbiodinium” species complex, within which they form seven different molecular types (Fr1–Fr7). Only one of these types (Fr1) branches within a group of invertebrate symbionts, previously described as type C. The remaining six types form sister groups to coral symbionts previously designed as types B, C, and D. Our data indicate a high genetic diversity and specificity of Symbiodinium-like symbionts in soritids. Except for type C, we have found no evidence for the transmission of symbionts between foraminifers and other symbiont-bearing invertebrates from the same localities. However, exchanges must have occurred frequently between the different species of Soritinae, as suggested by the lack of host specificity and some biogeographical patterns observed in symbiont distribution. Our data suggest that members of the subfamily Soritinae acquired their symbionts at least three times during their history, each acquisition being followed by a rapid diversification and independent radiation of symbionts within the foraminiferal hosts.