Bacteriophage Diversity: Schemes of Replication and Structures Splendidly Conceived

The study of bacteriophages, viruses that infect and replicate within prokaryotic cells, stands as a foundation for the discoveries and developments of molecular biology and beyond. Several big names in the history of modern science used bacteriophages (phages for short) during their careers. These include those who used phage as a model system for understanding basic biology (e.g., Hershey/Chase, Jacob/Monod, and the Lederbergs), those who took part in the summer phage course at Cold Spring Harbor (e.g., Watson and Feynman), and those who started in phage research prior to moving to new systems (e.g., Streisinger, who went on to develop zebrafish, Danio rerio, as a model organism). Scientists have accordingly long recognized the historical significance of phages and their use as a tool for molecular or genetic studies. But after the burst of phage research that birthed molecular biology, few labs continued actively studying phage biology on its own or its impact on life and the environment. The therapeutic potential of phages to treat infections originally appeared on the radar of researchers, largely became overshadowed with the development of antibiotics, and has now returned to mind because of the appreciation of antibiotic resistance. Moreover, affordable genomic isolation and sequencing technology and programs such as SEA-PHAGES have now reawakened an appreciation for the exceptional diversity of phage and the important contributions their activities have to all ecosystems.