Conjugation Mediates Large-Scale Chromosomal Transfer in Streptomyces Driving Diversification of Antibiotic Biosynthetic Gene Clusters.

Streptomyces are ubiquitous soil-dwelling bacteria with large, linear genomes that are of special importance as a source of metabolites used in human and veterinary medicine, agronomy, and industry. Conjugative elements (actinomycetes integrative and conjugative elements, AICEs) are the main drivers of Streptomyces Horizontal Gene Transfer. AICE transfer has long been known to be accompanied by mobilization of chromosomal DNA.

Prevalence and mobility of integrative and conjugative elements within a natural population.

Horizontal Gene Transfer (HGT) is a powerful force generating genomic diversity in bacterial populations. HGT in is in large part driven by conjugation thanks to plasmids, Integrative and Conjugative elements (ICEs) and Actinomycete ICEs (AICEs). To investigate the impact of ICE and AICE conjugation on genome evolution, we used and experimental approaches on a set of 11 very closely related strains isolated from a millimeter scale rhizosphere population.