Qi Qin, Rajabal Vaheesan, Ghaly Timothy M, Tetu Sasha G, Gillings Michael R
School of Natural Sciences, Macquarie University, Sydney, NSW, Australia.
ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, NSW, Australia.
Front Microbiol. 2023 Jan 19;14:1091391. doi: 10.3389/fmicb.2023.1091391. eCollection 2023.
Bacteriophages are versatile mobile genetic elements that play key roles in driving the evolution of their bacterial hosts through horizontal gene transfer. Phages co-evolve with their bacterial hosts and have plastic genomes with extensive mosaicism. In this study, we present bioinformatic and experimental evidence that temperate and virulent (lytic) phages carry integrons, including integron-integrase genes, / recombination sites and gene cassettes. Integrons are normally found in Bacteria, where they capture, express and re-arrange mobile gene cassettes integron-integrase activity. We demonstrate experimentally that a panel of sites carried in virulent phage can be recognized by the bacterial class 1 integron-integrase (IntI1) and then integrated into the paradigmatic recombination site using an x recombination assay. With an increasing number of phage genomes projected to become available, more phage-associated integrons and their components will likely be identified in the future. The discovery of integron components in bacteriophages establishes a new route for lateral transfer of these elements and their cargo genes between bacterial host cells.
噬菌体是多功能的可移动遗传元件，通过水平基因转移在推动其细菌宿主的进化中发挥关键作用。噬菌体与其细菌宿主共同进化，具有可塑性基因组且存在广泛的镶嵌现象。在本研究中，我们提供了生物信息学和实验证据，表明温和噬菌体和烈性（裂解性）噬菌体携带整合子，包括整合子整合酶基因、重组位点和基因盒。整合子通常存在于细菌中，在那里它们捕获、表达并重新排列移动基因盒以进行整合子整合酶活性。我们通过实验证明，烈性噬菌体携带的一组位点可被细菌1类整合子整合酶（IntI1）识别，然后使用x重组分析将其整合到典型的重组位点中。随着预计会有越来越多的噬菌体基因组可用，未来可能会鉴定出更多与噬菌体相关的整合子及其组成部分。噬菌体中整合子成分的发现为这些元件及其携带的基因在细菌宿主细胞之间的横向转移建立了一条新途径。
