Diverse evolutionary roots and mechanistic variations of the CRISPR-Cas systems

Adaptive immunity had been long thought of as an exclusive feature of animals. However, the discovery of the CRISPR-Cas defense system, present in almost half of prokaryotic genomes, proves otherwise. Because of the everlasting parasite-host arms race, CRISPR-Cas has rapidly evolved through horizont...

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Bibliographic Details
Main Authors: Mohanraju, Prarthana, Makarova, Kira S., Koonin, Eugene V., van der Oost, John, Zetsche, Bernd, Zhang, Feng
Other Authors: Broad Institute of MIT and Harvard
Format: Article
Language:en_US
Published: American Association for the Advancement of Science (AAAS) 2018
Online Access:http://hdl.handle.net/1721.1/113195
https://orcid.org/0000-0003-2782-2509
Description
Summary:Adaptive immunity had been long thought of as an exclusive feature of animals. However, the discovery of the CRISPR-Cas defense system, present in almost half of prokaryotic genomes, proves otherwise. Because of the everlasting parasite-host arms race, CRISPR-Cas has rapidly evolved through horizontal transfer of complete loci or individual modules, resulting in extreme structural and functional diversity. CRISPR-Cas systems are divided into two distinct classes that each consist of three types and multiple subtypes. We discuss recent advances in CRISPR-Cas research that reveal elaborate molecular mechanisms and provide for a plausible scenario of CRISPR-Cas evolution. We also briefly describe the latest developments of a wide range of CRISPR-based applications.