Cross-Regulation between Bacteria and Phages at a Posttranscriptional Level

The impact that the study of phages, both in their lytic form and as prophages integrated into bacterial chromosomes, has had on molecular biology and microbiology is hard to overstate. The ease of phage manipulation helped establish several of the central dogmas in molecular biology. For example, characterization of various phage DNA polymerases contributed to the understanding of replication (1, 2), and models of transcription regulation were greatly influenced by studies of cI, the phage ? repressor (3, 4). Phages also have continually provided important tools such as transduction, the phage-assisted movement of DNA from one bacterium to another, which has been an essential tool since the early years of molecular biology (5, 6). As another example, the development of chain termination DNA-sequencing approaches benefited from single-stranded DNA cloning vectors derived from phage M13 (7).