A short overview of the CRISPR-Cas adaptation stage

Citation metadata

Date: Jan. 2021
From: Canadian Journal of Microbiology(Vol. 67, Issue 1)
Publisher: NRC Research Press
Document Type: Report
Length: 9,937 words
Lexile Measure: 1370L

Document controls

Main content

Abstract :

CRISPR research began over 30 years ago with the incidental discovery of an unusual nucleotide arrangement in the Escherichia coli genome. It took 20 years to find the main function of CRISPR-Cas systems as an adaptive defence mechanism against invading nucleic acids, and our knowledge of their biology has steadily increased ever since. In parallel, the number of applications derived from CRISPR-Cas systems has risen spectacularly. The CRISPR-based genome editing tool is arguably the most exciting application in both basic and applied research. Lately, CRISPR-Cas research has partially shifted to the least understood aspect of its biology: the ability of CRISPR-Cas systems to acquire new immunities during the so-called adaptation step. To date, the most efficient natural system to readily acquire new spacers is the type II-A system of the gram-positive dairy bacterium Streptococcus thermophilus. The discovery of additional systems able to acquire new spacers will hopefully draw more attention to this step of CRISPR-Cas biology. This review focuses on the breakthroughs that have helped to unravel the adaptation phase and on questions that remain to be answered. Keywords: CRISPR-Cas, bacteriophage, plasmid, antiviral, defence, resistance. La recherche sur CRISPR a debute il y a plus de 30 ans avec la decouverte fortuite d'un arrangement inhabituel de nucleotides dans le genome d'Escherichia coli. Il a fallu 20 ans pour decouvrir la fonction principale des systemes CRISPR-Cas comme mecanisme de defense adaptative contre des acides nucleiques envahisseurs et notre connaissance de leur biologie s'est accrue regulierement depuis. En parallele, le nombre d'applications derivees des systemes CRISPR-Cas a augmente de maniere spectaculaire. L'outil d'edition du genome CRISPR-Cas9 est sans doute l'application la plus excitante tant en recherche fondamentale qu'en recherche appliquee. Recemment, la recherche sur CRISPR-Cas s'est partiellement orientee vers l'aspect le moins connu de sa biologie : la capacite des systemes CRISPR-Cas a acquerir de nouvelles immunites durant l'etape dite d'adaptation. A ce jour, le systeme naturel le plus efficace pour acquerir facilement de nouveaux espaceurs est le systeme de type II-A de la bacterie a Gram positif Streptococcus thermophilus. La decouverte de systemes supplementaires capables d'acquerir de nouveaux espaceurs devrait susciter davantage l'attention sur cette etape de la biologie de CRISPR-Cas. Cette synthese se concentre sur les percees qui ont permis de decortiquer la phase d'adaptation et sur les questions qui restent a resoudre. [Traduit par la Redaction] Mots-cles: CRISPR-Cas, bacteriophage, plasmide, antiviral, defense, resistance.

Source Citation

Source Citation   

Gale Document Number: GALE|A648001920