The number and diversity of known CRISPR–Cas systems have substantially increased in
recent years. Here, we provide an updated evolutionary classification of CRISPR–Cas …

In bacteria and archaea, clustered regularly interspaced short palindromic repeats
(CRISPR) and CRISPR-associated (Cas) proteins constitute an adaptive immune system …

Prokaryotes have evolved several defence mechanisms to protect themselves from viral
predators. Clustered regularly interspaced short palindromic repeats (CRISPR) and their …

The marine cyanobacterium Prochlorococcus is the smallest and most abundant
photosynthetic organism on Earth. In this Review, we summarize our understanding of the …

Evolution of bacteria and archaea involves an incessant arms race against an enormous
diversity of genetic parasites. Accordingly, a substantial fraction of the genes in most …

Background CRISPR (clustered regularly interspaced short palindromic repeats) RNAs
provide the specificity for noncoding RNA-guided adaptive immune defence systems in …

Our knowledge of prokaryotic defense systems has vastly expanded as the result of
comparative genomic analysis, followed by experimental validation. This expansion is both …

Bacteria have a range of distinct immune strategies that provide protection against
bacteriophage (phage) infections. While much has been learned about the mechanism of …

In the face of infectious disease, organisms evolved a range of defense mechanisms, with a
clear distinction between those that are constitutive (always active) and those that are …

CRISPR-Cas9 is a powerful technology that has enabled genome editing in a wide range of
species. However, the currently developed Cas9 homologs all originate from mesophilic …