Genomic plasticity in prokaryotes: the case of the square haloarchaeon

The variability in genome content among closely related strains of prokaryotes has been one of the most remarkable discoveries of genomics. One way to approach the description of this so- called pan- genome is to compare one reference strain genome with metagenomic sequences from the environment. We...

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Detalhes bibliográficos
Autores: Cuadros-Orellana, S, Martin-Cuadrado, AB, Legault, B, D'Auria, G, Zhaxybayeva, O, Papke, RT, Rodriguez-Valera, F
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2007
País:España
Recursos:Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunitat Valenciana (FISABIO)
Repositório:r-FISABIO. Repositorio Institucional de Producción Científica
OAI Identifier:oai:fisabio.fundanetsuite.com:p15693
Acesso em linha:https://fisabio.portalinvestigacion.com/publicaciones/15693
Access Level:Acceso aberto
Palavra-chave:pan-genome
metagenome
comparative genomics
species genome
halophile
haloquadratum
Descrição
Resumo:The variability in genome content among closely related strains of prokaryotes has been one of the most remarkable discoveries of genomics. One way to approach the description of this so- called pan- genome is to compare one reference strain genome with metagenomic sequences from the environment. We have applied this approach to one extreme aquatic habitat, saturated brines in a solar saltern. The genome of Haloquadratum walsbyi strain DSM 16790 was compared to an environmental metagenome obtained from the exact site of its isolation. This approach revealed that some regions of the strain genome were scarcely represented in the metagenome. Here we have analyzed these genomic islands ( GI) in the genome of DSM 16790 and compared them with the complete sequence of some fosmids from the environmental library. Two of the islands, GI 2 and GI 4, overlapped with two large guanine and cytosine ( GC)- rich regions that showed evidence of high variability through mobile elements. GI 3 seemed to be a phage or phage- remnant acquired by the reference genome, but not present in most environmental lineages. Most differential gene content was related to small molecule transport and detection, probably reflecting adaptation to different pools of organic nutrients. GI 1 did not possess traces of mobile elements and had normal GC content. This island contained the main cluster of cell envelope glycoproteins and the variability found was different from the other GIs. Rather than containing different genes it consisted of homologs with low similarity. This variation might reflect a phage evasion strategy.