Related Experiment Video
Updated: Jun 26, 2026

High-Resolution Comparison of Bacterial Conjugation Frequencies
Published on: January 10, 2019
Genomic islands: tools of bacterial horizontal gene transfer and evolution
Mario Juhas1, Jan Roelof van der Meer, Muriel Gaillard
1Clinical Microbiology and Infectious Diseases, Nuffield Department of Clinical Laboratory Sciences, University of Oxford, Oxford, UK. mario.juhas@ndcls.ox.ac.uk
Abstract:
Bacterial genomes evolve through mutations, rearrangements or horizontal gene transfer. Besides the core genes encoding essential metabolic functions, bacterial genomes also harbour a number of accessory genes acquired by horizontal gene transfer that might be beneficial under certain environmental conditions. The horizontal gene transfer contributes to the diversification and adaptation of microorganisms, thus having an impact on the genome plasticity. A significant part of the horizontal gene transfer is or has been facilitated by genomic islands (GEIs). GEIs are discrete DNA segments, some of which are mobile and others which are not, or are no longer mobile, which differ among closely related strains. A number of GEIs are capable of integration into the chromosome of the host, excision, and transfer to a new host by transformation, conjugation or transduction. GEIs play a crucial role in the evolution of a broad spectrum of bacteria as they are involved in the dissemination of variable genes, including antibiotic resistance and virulence genes leading to generation of hospital 'superbugs', as well as catabolic genes leading to formation of new metabolic pathways. Depending on the composition of gene modules, the same type of GEIs can promote survival of pathogenic as well as environmental bacteria.
Related Concept Videos
Horizontal Gene Transfer
Evolution of Microbial Genome
Genome Size and the Evolution of New Genes
Types of Genetic Transfer Between Organisms
Types of Genetic Transfer Between Organisms
Transduction

