Comparative analysis of integrative and conjugative mobile genetic elements in the genus .

Members of the genus are soil bacteria that often form nitrogen-fixing symbioses with legumes. Most characterised spp. genomes are ~8 Mb in size and harbour extensive pangenomes including large integrative and conjugative elements (ICEs) carrying genes required for symbiosis (ICESyms).

Evolutionary persistence of tripartite integrative and conjugative elements.

Integrative and conjugative elements (ICEs) are generally regarded as regions of contiguous DNA integrated within a bacterial genome that are capable of excision and horizontal transfer via conjugation. We recently characterized a unique group of ICEs present in Mesorhizobium spp., which exist as three entirely separate but inextricably linked chromosomal regions termed α, β and γ.