Université de Lorraine, INRAe, DynAMic, Nancy, F-54000, France.
Université de Lorraine, CNRS, Inria, LORIA, Nancy, F-54000, France.
Mol Biol Evol. 2024 Nov 1;41(11). doi: 10.1093/molbev/msae236.
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. 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 of Streptomyces result 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 "Streptomyces Chromosomal 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 specialized metabolite biosynthesis gene cluster diversification holds great promise in the discovery of new bioactive compounds including antibiotics.
链霉菌是一种广泛存在于土壤中的细菌，其线性基因组较大，具有重要意义，因为它们是用于人类和兽医医学、农业和工业的代谢物的重要来源。转导元件（放线菌整合和转导元件，AICE）是链霉菌水平基因转移的主要驱动因素。长期以来，人们已经知道 AICE 的转移伴随着染色体 DNA 的动员。然而，DNA 转移的程度，或者获得的 DNA 在其线性染色体上的定位，仍然没有确定。我们在这里表明，在共生的链霉菌菌株中，共轭交叉导致受体染色体的三分之一以上的大规模、全基因组分布的替换，我们将这种现象称为“链霉菌染色体转移”（SCT）。这种染色体混合导致专门的代谢物生物合成基因簇的获得、丢失和杂交，导致外共轭后代获得新的代谢武器。利用共轭介导的专门代谢物生物合成基因簇多样化在发现新的生物活性化合物（包括抗生素）方面具有很大的潜力。
