The endosymbiosis theory most widely accepted variant surmises the engulfment of a bacterial cell by an archaeal cell. For decades, this scenario was reputed to be an unconfirmed hypothesis, and only recently it has obtained an indirect proof in Asgard archaea environmental DNA encoding eukaryotic signatures − actin cytoskeleton, small GTPases, and ESCRT complex. In view of growing interest to this aspect of the endosymbiosis theory, it seemed timely to revisit the basic terms eukaryotic cell/eukaryotes/nucleated organisms. The article highlights the ambiguous applications of these terms, and seeks for their consistency with regard to phylogeny and taxonomy. Additionally, new name Caryosignifera is proposed for the phylum represented by: (1) the underexplored Asgard archaea manifested by above-mentioned environmental DNA; (2) cultured species of engulfing Asgard archaea; (3) eukaryotic host cells in nucleated organisms (protists, algae, plants, fungi, and animals).

最广泛接受的内共生理论推测细菌细胞被古细菌细胞吞噬。几十年来，这种情况一直被认为是未经证实的假设，直到最近，它才在编码真核生物特征——肌动蛋白细胞骨架、小 GTP 酶和 ESCRT 复合体的 Asgard 古细菌环境 DNA 中获得间接证据。鉴于对内共生理论这方面的兴趣日益增长，重新审视真核细胞/真核生物/有核生物的基本术语似乎是及时的。这篇文章强调了这些术语的模糊应用，并寻求它们在系统发育和分类学方面的一致性。此外，为代表的门提出了新名称 Caryosignifera：(1) 由上述环境 DNA 表现出来的未充分探索的 Asgard 古菌；(2) 吞没阿斯加德古菌的培养物种；(3) 有核生物（原生生物、藻类、植物、真菌和动物）中的真核宿主细胞。