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巨型病毒的广泛内生作用塑造了绿藻的基因组
2020-11-22 23:46

美国弗吉尼亚理工大学Frank O. Aylward研究组发现,巨型病毒的广泛内生作用塑造了绿藻的基因组。2020年11月18日,《自然》杂志在线发表了这一最新研究成果。

据研究人员介绍,内源性病毒元件(EVE)(将其基因组整合到其宿主的病毒)在真核生物中盛行,并在基因组进化中发挥重要作用。迄今为止,已鉴定出的绝大多数EVE是由少数基因组成的小基因组区域,但最近的证据表明,一些大型的双链DNA病毒也可能内生到宿主的基因组中。核细胞质大DNA病毒(NCLDV)由于其庞大的基因组和复杂的进化起源而引起了人们的极大兴趣,但尚不清楚它们是否是真核EVE的重要组成部分。

研究人员报道了NCLDV在各种绿藻中的广泛内生化;这些巨型EVE的大小超过100万个碱基对,并且在某些基因组中占总开放阅读框的10%左右,从而大大增加了真核生物基因组中已知病毒基因的规模。这些内源性元件通常与宿主基因组基因座共享基因,并包含大量剪接内含子和大量重复,表明它们与宿主基因组紧密融合。NCLDV包含大型和镶嵌基因组,其基因具有多个来源,它们的内生化表明新遗传物质进入真核细胞谱系的途径未得到充分认识,这可能会严重影响基因组的组成。

附:英文原文

Title: Widespread endogenization of giant viruses shapes genomes of green algae

Author: Mohammad Moniruzzaman, Alaina R. Weinheimer, Carolina A. Martinez-Gutierrez, Frank O. Aylward

Issue&Volume: 2020-11-18

Abstract: Endogenous viral elements (EVEs)—viruses that have integrated their genomes into those of their hosts—are prevalent in eukaryotes and have an important role in genome evolution1,2. The vast majority of EVEs that have been identified to date are small genomic regions comprising a few genes2, but recent evidence suggests that some large double-stranded DNA viruses may also endogenize into the genome of the host1. Nucleocytoplasmic large DNA viruses (NCLDVs) have recently become of great interest owing to their large genomes and complex evolutionary origins3,4,5,6, but it is not yet known whether they are a prominent component of eukaryotic EVEs. Here we report the widespread endogenization of NCLDVs in diverse green algae; these giant EVEs reached sizes greater than 1 million base pairs and contained as many as around 10% of the total open reading frames in some genomes, substantially increasing the scale of known viral genes in eukaryotic genomes. These endogenized elements often shared genes with host genomic loci and contained numerous spliceosomal introns and large duplications, suggesting tight assimilation into host genomes. NCLDVs contain large and mosaic genomes with genes derived from multiple sources, and their endogenization represents an underappreciated conduit of new genetic material into eukaryotic lineages that can substantially impact genome composition.

DOI: 10.1038/s41586-020-2924-2

Source: https://www.nature.com/articles/s41586-020-2924-2

Nature:《自然》,创刊于1869年。隶属于施普林格·自然出版集团,最新IF:43.07
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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