Unexpected evolutionary benefit to phages imparted by bacterial CRISPR-Cas9.

ABSTRACT: Bacteria and bacteriophages arm themselves with various defensive and counterdefensive mechanisms to protect their own genome and degrade the other's. CRISPR (clustered regularly interspaced short palindromic repeat)-Cas (CRISPR-associated) is an adaptive bacterial defense mechanism that recognizes short stretches of invading phage genome and destroys it by nuclease attack. Unexpectedly, we discovered that the CRISPR-Cas system might also accelerate phage evolution. When Escherichia coli bacteria containing CRISPR-Cas9 were infected with phage T4, its cytosine hydroxymethylated and glucosylated genome was cleaved poorly by Cas9 nuclease, but the continuing CRISPR-Cas9 pressure led to rapid evolution of mutants that accumulated even by the time a single plaque was formed. The mutatio

SUBMITTER: Tao P 

PROVIDER: S-EPMC5812732 | biostudies-literature | 2018 Feb

REPOSITORIES: biostudies-literature