Abstract:Quorum sensing is the ability of single-celled bacteria to regulate and synchronize target gene expression among a local population in response to cell density, so that a coordinate response is produced by whole population. Bacteria release signaling molecules called autoinducers that accumulate and increase in concentration according to cell density. The sensing of autoinducers by a bacterial population at a threshold stimulatory concentration leads to change in gene expression by switching the genes on that controlled by quorum sensing. Since Fuqua proposed the concept of quorum sensing in 1994, quorum sensing has become a research hotspot in the field of microbiology. In recent years, quorum sensing has been increasingly discovered in fungi and bacteriophages. Especially since 2017, Professor Erez has found quorum sensing phenomenon in a variety of phages including Bacillus subtilis phages, which regulates the lysogeny-lysis pathway conversion. In addition, a nunmber of other studies have found quorum sensing in other phages. This paper attempts to summarize the recent development in phage quorum sensing systems and their molecular mechanisms.