AUTHOR=Wang Ying , Deng Jianfeng , Ren Jianle , Liang Libin , Li Junping , Niu Sheng , Wu Xingchen , Zhao Yujun , Gao Shimin , Yan Fang , Liu Yuqing , Ma Haili , Tian Wen-xia , Yan Yi 

TITLE=RAP44 phage integrase-guided 50K genomic island integration in Riemerella anatipestifer

JOURNAL=Frontiers in Veterinary Science

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2022.961354

DOI=10.3389/fvets.2022.961354

ISSN=2297-1769

ABSTRACT=<p>Bacteriophages are viruses that infect bacteria. Bacteria and bacteriophages have been fighting for survival. Over time, the evolution of both populations has been affected. Pathogenic Flavobacteriaceae species including <italic>Riemerella anatipestifer</italic> mainly infects ducklings, geese, and turkeys. However, it does not infect humans, rats, or other mammals, and is a suitable and safe research object in the laboratory. Our previous study showed that there is a 10K genomic island in <italic>R. anatipestifer</italic>In this study, we found another integrated 50K genomic islands and focused on the relationship between <italic>R. anatipestifer</italic> genomic islands and the RAP44 phage genome. The phage RAP44 genome was integrated into <italic>R. anatipestifer</italic> chromosome, and an evolutionary relationship was evident between them in our comparative analysis. Furthermore, the integrated defective RAP44 phage sequence had the function of integration, excision, and cyclization automatically. Integrases are important integration elements. The integrative function of integrase was verified in <italic>R. anatipestifer</italic>. The integrase with the attP site can be integrated stably at the attB locus of the <italic>R. anatipestifer</italic> genome. A recombinant strain can stably inherit and express the exogenous gene. By studying the integration between host bacterium and phage, we have provided evidence for the evolution of the genomes in <italic>R. anatipestifer</italic>.</p>