The Year in CRISPRs - 10

Improving
CRISPR Specificity
T

he field of molecular biology was set ablaze
several years ago with the discovery of the
CRISPR-Cas9 genome editing enzymes from
Staphylococcus pyogenes. In the three-year
stretch since the original publication describing
CRISPR's activity and uses, over 1,300 papers have
since gone on to further expound the numerous
applications of this molecular editing tool.
However, like any new discovery, CRISPR-Cas9
does come with its own unique set of limitations
that researchers have been diligently trying to
overcome. As accurate as CRISPRs can be, with
respect to the genomic sequence that they
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intend to edit, many researchers have noticed
that the enzymes will cut off-target sites a small
percentage of the time. This is particularly
problematic when using CRISPR as an
instrument for gene therapy, as off target
genomic alterations can have large deleterious
effects to the patient.

Described in the current issue of Human
Gene Therapy, which focuses on genome
editing, the findings from this study were
published in July through an article entitled
"Dimeric CRISPR RNA-Guided FokI-dCas9
Nucleases Directed by Truncated gRNAs
for Highly Specific Genome Editing."

Yet, researchers from the Massachusetts
General Hospital and Harvard Medical School
believe they have developed a highly specific
platform for performing genome editing by
combining two recently described novel strategies
designed to improve Cas9 cleavage specificity.

Specifically, the investigators combined
truncated guide RNAs (tru-gRNAs) with a
fused, dimerization-dependent non-specific
FokI cleavage domain to a catalytically inactive
Cas9 protein (RFN). Both of these approaches
have been shown separately to enhance the


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The Year in CRISPRs

Table of Contents for the Digital Edition of The Year in CRISPRs

Contents
The Year in CRISPRs - 1
The Year in CRISPRs - 2
The Year in CRISPRs - 3
The Year in CRISPRs - Contents
The Year in CRISPRs - 5
The Year in CRISPRs - 6
The Year in CRISPRs - 7
The Year in CRISPRs - 8
The Year in CRISPRs - 9
The Year in CRISPRs - 10
The Year in CRISPRs - 11
The Year in CRISPRs - 12
The Year in CRISPRs - 13
The Year in CRISPRs - 14
The Year in CRISPRs - 15
The Year in CRISPRs - 16
The Year in CRISPRs - 17
The Year in CRISPRs - 18
The Year in CRISPRs - 19
The Year in CRISPRs - 20
The Year in CRISPRs - 21
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