Different genetic and morphological outcomes for phages targeted by single or multiple CRISPR-Cas spacers.

ABSTRACT: CRISPR-Cas systems provide bacteria and archaea with adaptive immunity against genetic invaders, such as bacteriophages. The systems integrate short sequences from the phage genome into the bacterial CRISPR array. These 'spacers' provide sequence-specific immunity but drive natural selection of evolved phage mutants that escape the CRISPR-Cas defence. Spacer acquisition occurs by either naive or primed adaptation. Naive adaptation typically results in the incorporation of a single spacer. By contrast, priming is a positive feedback loop that often results in acquisition of multiple spacers, which occurs when a pre-existing spacer matches the invading phage. We predicted that single and multiple spacers, representative of naive and primed adaptation, respectively, would cause differing outc

SUBMITTER: Watson BNJ 

PROVIDER: S-EPMC6452268 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature