Conjugation mediates large-scale chromosomal transfer inStreptomycesdriving diversification of antibiotic biosynthetic gene clusters

Abstract

AbstractStreptomycesare ubiquitous soil dwelling bacteria of special importance as a source of metabolites used in human and veterinary medicine, agronomy and industry. Conjugation is the main mechanism ofStreptomycesHorizontal Gene Transfer, and this process has long been known to be accompanied by mobilization of chromosomal DNA. However, the magnitude of DNA transfer, or the localization of acquired DNA across their linear chromosome, has remained undetermined. We here show that conjugative crossings in sympatric strains ofStreptomycesresult in the large-scale, genome-wide distributed replacement of up to one third of the recipient chromosome, a phenomenon for which we propose the name ‘StreptomycesChromosomal Transfer’ (SCT). Such chromosome blending results in the acquisition, loss and hybridization of Specialized Metabolite Biosynthetic Gene Clusters, leading to a novel metabolic arsenal in exconjugant offspring. Harnessing conjugation-mediated SMBGC diversification holds great promise in the discovery of new bioactive compounds including antibiotics.