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中外科学家合作揭示Asgard古细菌的多样性及其与真核生物的关系
2021-04-30 15:19

中国深圳大学Meng Li和美国国立卫生研究院Eugene V. Koonin团队合作揭示了阿斯加德古细菌的多样性及其与真核生物的关系。这一研究成果在线发表在2021年4月28日出版的国际学术期刊《自然》上。

研究人员对Asgard古细菌的162个完整或接近完整的基因组进行了比较分析,其中包括75个由超基因组组装成的基因组,据研究人员介绍,这些基因组先前都没有被报道过。该结果扩展了Asgard的系统发育多样性,并促使研究人员发现了另外六个系统发育分支,包括一个深分支,并暂命名为Wukongarchaeota。该系统生物学分析并不能明确地解决真核生物和Asgard古细菌之间的进化关系,而是通过物种选择和用于构建系统发育的保守基因揭示了真核生物古细菌起源于Asgard内部(作为扩展的Heimdallarchaeota–Wukongarchaeota分支或古细菌内真核祖先的更深分支)。

研究人员对这162个Asgard基因组进行了全面的蛋白质结构域分析,扩展了真核标签蛋白集。Asgard真核标签蛋白显示出可变的系统分布和域结构,这表明通过水平基因转移、基因丢失、基因重复和域改组而产生动态进化。Asgard古细菌的系统组学研究表明,通过广泛的水平基因转移,真核生物古细菌祖先(在Asgard内或外)中可移动 “ eukaryome”成分的积累。

据介绍,Asgard是最近发现的古细菌超级菌种,似乎是与真核生物最接近的古细菌菌系。关于真核生物的古细菌祖先是否属于阿斯加德超门之内还是该祖先是其它所有其他古细菌的姊妹群体(即两域生命树与三域生命树)的争论仍在继续。

附:英文原文

Title: Expanded diversity of Asgard archaea and their relationships with eukaryotes

Author: Yang Liu, Kira S. Makarova, Wen-Cong Huang, Yuri I. Wolf, Anastasia N. Nikolskaya, Xinxu Zhang, Mingwei Cai, Cui-Jing Zhang, Wei Xu, Zhuhua Luo, Lei Cheng, Eugene V. Koonin, Meng Li

Issue&Volume: 2021-04-28

Abstract: Asgard is a recently discovered superphylum of archaea that appears to include the closest archaeal relatives of eukaryotes1,2,3,4,5. Debate continues as to whether the archaeal ancestor of eukaryotes belongs within the Asgard superphylum or whether this ancestor is a sister group to all other archaea (that is, a two-domain versus a three-domain tree of life)6,7,8. Here we present a comparative analysis of 162 complete or nearly complete genomes of Asgard archaea, including 75 metagenome-assembled genomes that—to our knowledge—have not previously been reported. Our results substantially expand the phylogenetic diversity of Asgard and lead us to propose six additional phyla that include a deep branch that we have provisionally named Wukongarchaeota. Our phylogenomic analysis does not resolve unequivocally the evolutionary relationship between eukaryotes and Asgard archaea, but instead—depending on the choice of species and conserved genes used to build the phylogeny—supports either the origin of eukaryotes from within Asgard (as a sister group to the expanded Heimdallarchaeota–Wukongarchaeota branch) or a deeper branch for the eukaryote ancestor within archaea. Our comprehensive protein domain analysis using the 162 Asgard genomes results in a major expansion of the set of eukaryotic signature proteins. The Asgard eukaryotic signature proteins show variable phyletic distributions and domain architectures, which is suggestive of dynamic evolution through horizontal gene transfer, gene loss, gene duplication and domain shuffling. The phylogenomics of the Asgard archaea points to the accumulation of the components of the mobile archaeal ‘eukaryome’ in the archaeal ancestor of eukaryotes (within or outside Asgard) through extensive horizontal gene transfer.

DOI: 10.1038/s41586-021-03494-3

Source: https://www.nature.com/articles/s41586-021-03494-3

Nature:《自然》,创刊于1869年。隶属于施普林格·自然出版集团,最新IF:69.504
官方网址:http://www.nature.com/
投稿链接:http://www.nature.com/authors/submit_manuscript.html


本期文章:《自然》:Online/在线发表

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