New home for tiny symbionts: dinophytes determined as Zooxanthella are Peridiniales and distantly related to Symbiodinium.
New home for tiny symbionts: dinophytes determined as Zooxanthella are Peridiniales and distantly related to Symbiodinium.
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DOI：
10.1016/j.ympev.2013.01.003
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发表时间：
2013-04
影响因子：
4.1
通讯作者：
M. Gottschling;T. McLean
中科院分区：
文献类型：
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作者：
M. Gottschling;T. McLean
内共生恐龙种类繁多，存在于多种水生伙伴中。它们被俗称为虫黄藻，关于那些与珊瑚为伙伴的恐植物(即共生藻)的知识是广泛的。然而，根据从放射虫中分离到的材料对其进行了专门的描述，目前它在恐龙中的系统发育位置尚不清楚。我们从放射虫中发现的一种内共生植物中分离出基因组DNA，并对核糖体RNA基因进行了测序。在系统发育分析中，内共生菌与共生纲和苏珊瑚目有较远的亲缘关系，但与绒毛目的成员聚在一起。具体地说，这是一个小群体的姐妹血统，其成员拥有一种硅藻作为内共生体(即恐龙)。因此，内共生在恐植物中具有多重来源，需要进行更多的研究，以找出与DNA树一致的生态和形态特征。
Endosymbiotic dinophytes are diverse and are found in a large variety of aquatic partners. They are colloquially coined zooxanthellae, and knowledge about those dinophytes with a coral as partner (i.e., Symbiodinium) is extensive. However, Zooxanthella nutricula has been specifically described based on material isolated from radiolarians, and its phylogenetic position within the dinophyte tree is unclear at present. We isolated genomic DNA and sequenced the ribosomal RNA genes from an endosymbiotic dinophyte found in a radiolarian. In phylogenetic analyses, the endosymbiont was distantly related to Symbiodinium and the Suessiales, but clustered together with members of the Peridiniales. Specifically, it was the sister lineage of a small group, whose members host a diatom as endosymbiont (i.e., the dinotoms). Endosymbiosis is thus of multiple origin within the dinophytes, and more research is necessary to work out ecological and morphological character traits that are congruent to the DNA trees.