Dean Mckeown, Alexandre Cormier, Declan Schroeder, Arnaud Couloux, Nachida Tadrent, J Mark Cock, Erwan Corre
{"title":"Multiple, diverse endogenous giant virus elements within the genome of a brown alga.","authors":"Dean Mckeown, Alexandre Cormier, Declan Schroeder, Arnaud Couloux, Nachida Tadrent, J Mark Cock, Erwan Corre","doi":"10.1093/ve/veaf009","DOIUrl":null,"url":null,"abstract":"<p><p>Endogenous viral elements (EVEs) have been found in diverse eukaryotic genomes. These elements are particularly frequent in the genomes of brown algae (Phaeophyceae) because these seaweeds are infected by viruses (<i>Phaeovirus</i>) of the phylum <i>Nucleocytoviricota</i> (NCV) that are capable of inserting into their host's genome as part of their infective cycle. A search for inserted viral sequences in the genome of the freshwater brown alga <i>Porterinema fluviatile</i> identified seven large EVEs, including four complete or near-complete proviruses. The EVEs, which all appear to have been derived from independent insertion events, correspond to phylogenetically diverse members of the <i>Phaeovirus</i> genus and include members of both the A and B subgroups of this genus. This latter observation is surprising because the two subgroups were thought to have different evolutionary strategies and were therefore not expected to be found in the same host. The EVEs contain a number of novel genes including a H4 histone-like sequence but only one of the EVEs possesses a full set of NCV core genes, indicating that the other six probably correspond to nonfunctional, degenerated viral genomes. The majority of the genes within the EVEs were transcriptionally silent and most of the small number of genes that showed some transcriptional activity were of unknown function. However, the existence of some transcriptionally active genes and several genes containing introns in some EVEs suggests that these elements may be undergoing some degree of endogenization within the host genome over time.</p>","PeriodicalId":56026,"journal":{"name":"Virus Evolution","volume":"11 1","pages":"veaf009"},"PeriodicalIF":5.5000,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11890097/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Virus Evolution","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1093/ve/veaf009","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2025/1/1 0:00:00","PubModel":"eCollection","JCR":"Q1","JCRName":"VIROLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Endogenous viral elements (EVEs) have been found in diverse eukaryotic genomes. These elements are particularly frequent in the genomes of brown algae (Phaeophyceae) because these seaweeds are infected by viruses (Phaeovirus) of the phylum Nucleocytoviricota (NCV) that are capable of inserting into their host's genome as part of their infective cycle. A search for inserted viral sequences in the genome of the freshwater brown alga Porterinema fluviatile identified seven large EVEs, including four complete or near-complete proviruses. The EVEs, which all appear to have been derived from independent insertion events, correspond to phylogenetically diverse members of the Phaeovirus genus and include members of both the A and B subgroups of this genus. This latter observation is surprising because the two subgroups were thought to have different evolutionary strategies and were therefore not expected to be found in the same host. The EVEs contain a number of novel genes including a H4 histone-like sequence but only one of the EVEs possesses a full set of NCV core genes, indicating that the other six probably correspond to nonfunctional, degenerated viral genomes. The majority of the genes within the EVEs were transcriptionally silent and most of the small number of genes that showed some transcriptional activity were of unknown function. However, the existence of some transcriptionally active genes and several genes containing introns in some EVEs suggests that these elements may be undergoing some degree of endogenization within the host genome over time.
期刊介绍:
Virus Evolution is a new Open Access journal focusing on the long-term evolution of viruses, viruses as a model system for studying evolutionary processes, viral molecular epidemiology and environmental virology.
The aim of the journal is to provide a forum for original research papers, reviews, commentaries and a venue for in-depth discussion on the topics relevant to virus evolution.