捷克查尔斯大学Ivan ?epi?ka团队与美国密西西比州立大学Matthew W. Brown团队发现了罕见的微生物遗迹揭示了一个古老的真核生物超群。2025年11月19日出版的《自然》发表了这项成果。

在这里，课题组研究人员报道了这样一种单细胞真核生物的发现，即新属新种 Solarion arienae gen. et sp. nov.，它是一种不显眼的、自由生活的异养原生生物，具有两种形态不同的细胞类型和一种新型的捕食性喷射体。我们将其归入新的门，Caelestes。它与 Provora、半鞭毛虫类（hemimastigophoreans）以及 Meteora 一起，共同构成了一个新的真核生物超群，Disparia。

此外，S. arienae还具有一些值得注意的与线粒体基因组相关的性状；特别是线粒体编码的secA基因，这是祖先α变形菌蛋白分泌途径的残余，在现存的线粒体中几乎完全丢失了。S. arienae的发现拓宽了他们对早期真核生物进化的认识，促进了对原线粒体代谢残留物的研究，揭示了祖先真核生物的复杂性。

据了解，在过去的十年里，研究人员对真核生物进化的理解有了极大的提高。新发现的真核生物超群已经建立了，并且大多数神秘的孤儿谱系已经解决了它们的关系。对单细胞原生真核生物的研究也是理解线粒体进化的关键，线粒体是真核细胞的基本细胞器，起源于α变形菌的祖先。在一些原生生物谱系中保留了祖先的α变形菌途径，这表明最后真核生物共同祖先的线粒体比大多数现代真核生物中发现的高度衍生的线粒体代谢更多样化。

附：英文原文

Title: Rare microbial relict sheds light on an ancient eukaryotic supergroup

Author: Valt, Marek, Pnek, Tom, Mirzoyan, Seda, Tice, Alexander K., Jones, Robert E., Dohnlek, Vt, Doleal, Pavel, Miktko, Ji, Rotterov, Johana, Hrub, Pavla, Brown, Matthew W., epika, Ivan

Issue&Volume: 2025-11-19

Abstract: During the past decade, our understanding of eukaryotic evolution has increased immensely. Newly recognized eukaryotic supergroups have been established1,2,3, and most enigmatic orphan lineages have had their relationships resolved4,5,6. Studies on unicellular protist eukaryotes have also been key to understanding the evolution of mitochondria, the fundamental organelles of the eukaryotic cell, which originated from an alphaproteobacterial ancestor. The retention of ancestral alphaproteobacterial pathways in some protist lineages reveals that the mitochondrion of the last eukaryotic common ancestor was more metabolically versatile than are the highly derived mitochondria that are found in most modern eukaryotes7,8. Here we report the discovery of such a unicellular eukaryote, Solarion arienae gen. et sp. nov., an inconspicuous, free-living heterotrophic protist with two morphologically distinct cell types and a novel type of predatory extrusome. We assign Solarion to the new phylum Caelestes. Together with Provora, hemimastigophoreans and Meteora, they form a new eukaryotic supergroup, Disparia. Moreover, S. arienae has some noteworthy traits associated with the mitochondrial genome; in particular, the mitochondrially encoded secA gene, a remnant of an ancestral alphaproteobacterial protein secretion pathway, which has been lost almost entirely in extant mitochondria9,10. The discovery of S. arienae broadens our understanding of early eukaryotic evolution and facilitates the study of proto-mitochondrial metabolic remnants, shedding light on the complexity of ancestral eukaryotic life.

DOI: 10.1038/s41586-025-09750-0

Source: https://www.nature.com/articles/s41586-025-09750-0