A new report in Nature Communications by Chaverra-Rodriguez et al. details a novel Cas9-delivery approach for insect genetic modification. In their work, Chaverra-Rodriguez et al introduce a technology they term “ReMOT control”, or Receptor-Mediated Ovary Transduction of Cargo. In their […]
William Reid
Gene Drive in a Major Agricultural Pest
In a recent report in PNAS, Buchman et al. (2018) describe the construction and development of a MEDEA-based gene drive system in the crop pest, Drosophila suzukii. Buchman et al revisited the MEDEA-based gene drive approach developed in D. melanogaster […]
Redkmer – a computational tool to identify X-linked targets for CRISPR-based sex distortion in insects
In the inaugural volume of The CRISPR Journal, Philippos Papathanos and Nikolai Windbichler describe a computational pipeline they call redkmer, which identifies repetitive CRIPSR target sites for X-shredding systems in insects. Back in 2007, Windbichler et al. found that the […]
CRISPR-SD, a programmable Cas9 approach to generating X-shredder lines in insects with XY mating systems
In a recent paper in Scientific Reports, Galizi, Hammond, et al report on the use of CRISPR-Cas9 to develop a sex-distortion system in Anopheles gambiae, which they termed CRISPRSD. Earlier, the group had demonstrated that transgenic An. gambaie expressing the […]
Intramolecular interactions in gRNA may influence Cas9 cleavage activity
In an article recently published in Nature Communications, Thyme et al (2016) discuss the interactions of the sequences of sgRNAs, the role of chromatin, and how these factors might interfere with Cas9 cleavage activity. By investigating the activity of Cas9 […]
CHOPCHOP v2: Improved online CRISPR/Cas9 target prediction tool
In a paper published in Nucleic Acids Research, Labun et al. (2016), the developers of CHOPCHOP, report on their updated version: CHOPCHOPv2 . The first version of CHOPCHOP was released by a team of researchers from Harvard University a little […]
Phosphorothioate oligomers increase knock-in frequency and precision in TALEN- and Cas9-mediated genome editing
In a recent paper by Renaud et al. (2016), the authors investigate methods to increase genome editing knock-in efficiency by modifying the chemistry of the donor oligomers to be resistant to nuclease activity. The modifications they tested included locked nucleic […]
Enhancing Homology Repair-Mediated Genome Editing
In a recent paper in Nature Biotechnology, Richardson et al (2016) report on the interaction of target-site bound Cas9 and dCas9 on DNA strand accessibility- and have identified an optimized approach to increase homologous recombination (HR) mediated repair. They found […]
Active CRISPR guide-design: Still somewhat of a black box
To add to the growing knowledge base for gRNA design, Wong et al (2015) revisit the data generated by Doench et al (2014), which employed a lentivirus library to screen >1800 sgRNA for activity in mouse EL4 cells. The authors […]
Cas9-VPR: Activator, Repressor and Nuclease All in One Cell
In a recent communication in Nature Methods Kiani et al investigated the use of Cas9-VPR to serve simultaneously as an DNA endonuclease and a gene activator/repressor. That native Cas9 could be used for both purposes at the same time hinged […]
CRISPRscan – A Tool Aiding Selection of CRISPR-Cas9 gRNAs
Just published online in Nature Methods, Moreno-Mateos et al report testing the activities of >1200 gRNAs in zebrafish embryos and used the results to create an algorithm for predicting gRNA efficacy. The advent of the CRISPR-Cas9 system has revolutionized genome […]
CRISPR-Cas9 mediated “Mutagenic Chain Reaction”
A recent paper in Science by Gantz and Bier (2015) investigated the potential of utilizing the CRISPR-Cas9 system as, essentially, a programmable homing endonuclease to generate homozygous loss-of-function (LOF) mutants. Advances in genome editing have allowed for the directed generation of […]
Chemically Inducible Cas9 System
The development of a controllable Cas9 system that is chemically inducible would greatly enhance the experimental utility of the CRISPR Cas9 system. In the CRISPR Cas9 system, a guide RNA directs the Cas9 endonuclease to a specific region within the […]
Off- & On-Target Editing Evaluation
Off-target effects and overall efficacy are major considerations in the design of tools for genome editing. In a recent issue of Trends in Biotechnology, Hendel et al review methods used to assess both the efficacy of genome editing technologies as […]
Hi, Tide.
The use of sequence-targeting nucleases (TALENs, CRISPR-Cas9, zinc finger nucleases) to introduce small insertions/deletions into the genome of an organism is an effective means of generating specific mutants. Although these technologies are effective, they still require testing and optimization to […]
Guide RNA Design & Off-Target Analysis: A Tool for Non-Model Organisms
Modifying genomes using the CRISPR/Cas9 system is becoming popular. Good prior planning can save you much time and effort, and could mean the difference between success and failure. Designing your guide RNAs is your first major challenge. There are multiple […]