IBBM   21076
INSTITUTO DE BIOTECNOLOGIA Y BIOLOGIA MOLECULAR
Unidad Ejecutora - UE
capítulos de libros
Título:
Horizontal Gene Transfer, Generalities and Lessons from Rhizobia.
Autor/es:
TORRES TEJERIZO, G.; GIUSTI, M. A.; DEL PAPA M. F.; LOZANO, M. J.; DRAGHI, W. O.; JOFRE, E.; LAGARES A.; PISTORIO M
Libro:
Microbial Populations
Editorial:
Research Singpost
Referencias:
Año: 2010; p. 37 - 59
Resumen:
One of the evolutionary mechanisms that defy the
understanding of the dynamics of bacterial genome is Horizontal Gene Transfer
(HGT), which has been most recently evident with the massive sequencing of
genomes. The HGT material together with the processes of transposition and
recombination are the principal mechanisms that operate in prokaryote genome
evolution. The acquisition of new DNA via horizontal genetic transfer can even
promote speciation among bacterial lineages The HGT between bacteria is accomplished
by at least three known mechanisms: transformation, transduction and
conjugation. Within this context, special attention has been paid to the
transfer of genetic material in bacteria via plasmid conjugation since this
mechanism is considered one of most efficient means of DNA exchange among
prokaryotes. In several rhizobia, bacteria that inhabit the soil in free-living
conditions and associate in symbiosis with the root of legumes as
nitrogen-fixing organisms, plasmid DNA could constitute a very high percentage
of the genome. Conjugal transfer of rhizobial plasmids has been well documented
since decades ago both for symbiotic and for cryptic plasmids or mobilizable.
The wide distribution of mobile genetic elements in rhizobia makes the
functional and phenotypic study of them a relevant focus of analysis to
understand the mechanisms of adaptation, speciation and the genomes plasticity
of soil microorganisms.