Expanding Asgard members in the domain of Archaea sheds new light on the origin of eukaryotes  

作　　者：Ruize Xie Yinzhao Wang Danyue Huang Jialin Hou Liuyang Li Haining Hu Xiaoxiao Zhao Fengping Wang 

机构地区：[1]School of Oceanography,Shanghai Jiao Tong University,Shanghai,200030,China [2]State Key Laboratory of Microbial Metabolism,School of Life Sciences and Biotechnology,Shanghai Jiao Tong University,Shanghai,200240,China [3]Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),Zhuhai,519082,China

出　　处：《Science China(Life Sciences)》2022年第4期818-829,共12页中国科学（生命科学英文版）

基　　金：supported by the National Natural Science Foundation of China (91751205, 41921006, 41902313, 92051116);the China Ocean Mineral Resources R&D Association (COMRA) project (DY135-B2-12);the National Key Research and Development Project of China (2018YFC0310803);the Senior User Project of RV KEXUE (KEXUE2019GZ06)

摘　　要：The hypothesis that eukaryotes originated from within the domain Archaea has been strongly supported by recent phylogenomic analyses placing Heimdallarchaeota-Wukongarchaeota branch from the Asgard superphylum as the closest known archaeal sister-group to eukaryotes. However, our understanding is still limited in terms of the relationship between eukaryotes and archaea, as well as the evolution and ecological functions of the Asgard archaea. Here, we describe three previously unknown phylum-level Asgard archaeal lineages, tentatively named Sigyn-, Freyr-and Njordarchaeota. Additional members in Wukongarchaeota and Baldrarchaeota from distinct environments are also reported here, further expanding their ecological roles and metabolic capacities. Comprehensive phylogenomic analyses further supported the origin of eukaryotes within Asgard archaea and a new lineage Njordarchaeota was supposed as the known closest branch with the eukaryotic nuclear host lineage. Metabolic reconstruction suggests that Njordarchaeota may have a heterotrophic lifestyle with capability of peptides and amino acids utilization, while Sigynarchaeota and Freyrarchaeota also have the potentials to fix inorganic carbon via the Wood-Ljungdahl pathway and degrade organic matters. Additionally, the Ack/Pta pathway for homoacetogenesis and de novo anaerobic cobalamin biosynthesis pathway were found in Freyrarchaeota and Wukongrarchaeota,respectively. Some previously unidentified eukaryotic signature proteins for intracellular membrane trafficking system, and the homologue of mu/sigma subunit of adaptor protein complex, were identified in Freyrarchaeota. This study expands the Asgard superphylum, sheds new light on the evolution of eukaryotes and improves our understanding of ecological functions of the Asgard archaea.

关 键 词：Asgard archaea eukaryotic origin METAGENOME 

分 类 号：Q10[生物学—普通生物学]