R-loop formation by dCas9 is mutagenic in Saccharomyces cerevisiae.

ABSTRACT: Cas9 binds and cleaves specific DNA sequences by inducing the formation of an R-loop between the guide RNA and its genomic target. While targeting of active Cas9 to a genomic locus is highly mutagenic because Cas9 creates DNA double strand breaks, targeting of dead Cas9 (dCas9) is presumed not to be mutagenic, as dCas9 lacks DNA endonuclease activity. Here, we show that dCas9 targeting induces mutations in yeast, particularly when targeted to the non-transcribed strand of a gene. dCas9-induced mutations cluster near the guide RNA target region and are comprised of single nucleotide substitutions, small insertions and deletions, and even complex mutations, depending upon the particular guide RNA target. We show that many of these mutations are a consequence of cytosine deamination events oc

SUBMITTER: Laughery MF 

PROVIDER: S-EPMC6411842 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature