Establishing Host–Virus Link Through Host Metabolism: Viral DNA SIP Validation Using T4 Bacteriophage and E. coli

DNA Stable Isotope Probing is emerging as a potent methodology for investigating host–virus interactions, based on the essential reliance of viruses on host organisms for the production of virions. Despite the anticipated link between host isotopic compositions and the generated virions, the application of stable isotope probing to viral DNA has never been evaluated on simple biological models. In this study, we assessed the efficacy of this method on the bacteriophage T4 and its host, Escherichia coli. Through the cultivation of E. coli cells on a ¹³C-enriched substrate and subsequent propagation of T4 bacteriophage, we examine the degree of isotopic enrichment in viral DNA. Our investigation reveals a strong correlation between the proportion of ¹³C₆-d-glucose in the growth substrate and the buoyant density in CsCl gradient of T4 DNA, confirming the validity of DNA SIP in viral ecology. These findings underscore the potential of DNA SIP as a robust tool for characterizing the diversity of viruses infecting hosts with specific metabolic activities and provide then a foundation for further exploration in viral ecology research.