Horizontal Gene Transfer in Thermus spp.

The small amount of genetic content in thermophiles generally limits their adaptability to environmental changes. In Thermus spp., very active horizontal gene transfer (HGT) mechanisms allow the rapid spread of strain-specific adaptive gene modules among the entire population. Constitutive expressio...

Descripción completa

Detalles Bibliográficos
Autores: Blesa Esteban, Alba Mercedes, Averhoff, Beate, Berneguer, José
Tipo de recurso: artículo
Fecha de publicación:2018
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/98126
Acceso en línea:https://hdl.handle.net/20.500.14352/98126
Access Level:acceso abierto
Palabra clave:576.8
579.6
615.28
Horizontal
Transfer
Thermus
Microbiología (Farmacia)
Parasitología (Farmacia)
24 Ciencias de la Vida
Descripción
Sumario:The small amount of genetic content in thermophiles generally limits their adaptability to environmental changes. In Thermus spp., very active horizontal gene transfer (HGT) mechanisms allow the rapid spread of strain-specific adaptive gene modules among the entire population. Constitutive expression of a rather particular and highly efficient DNA transport apparatus (DTA) is at the center of this HGT-mediated enhanced adaptability. The function of the DTA is dependent on the integrity and longevity of the extracellular DNA (eDNA) being transformed, which can be improved by the production of extracellular vesicles (EV) through lysis of a fraction of the population. The DTA must also contend with the recipient cell's defensive barriers, namely restriction enzymes, a panoply of CRISPR-Cas systems, and the argonaute-like protein TtAgo, which may be bypassed by transjugation, a new class of bidirectional transformation-dependent conjugation. Efficient transjugation depends on the presence of the ICETh1, an integrative and conjugative element which promotes simultaneous, generalized DNA transfer from several points in the genome. Transjugation shows preference for genes located within a megaplasmid replicon, where the main strain-specific adaptive modules are located. Contribution of transformation, vesicle-mediated eDNAs, and transjugation to HGT in this genus is discussed.