GM mosquitoes play rock paper scissors

Anti-CRISPR proteins are the rock needed to stop CRISPR-based mosquito-eradicating gene drives, if necessary, and make them safer. In a news feature published last year in Nature, the molecular parasitologist Andrea Crisanti disclosed unpublished data about halting an anti-malaria gene-drive system by adding anti-drive mosquitoes to the mix. “They can completely, 100% block the drive. We can stop the [Anopheles gambiae] population from crashing,” he said. According to the scientist from the Imperial College London, it’s kind of like buying an insurance. Looking ahead to field-testing his sterilization strategy, Crisanti imagined having cages of anti-drive mosquitoes at the ready, just in case things go awry. Well, that work is now published, and anti-drive mosquitoes are a reality. To learn more, see the paper published on June 25 in Nature Communications by Chrysanthi Taxiarchi et al.

CRISPR Ikea-style

Modular design is the latest trend for developing new CRISPR tools. In The CRISPR Journal, Juan Carlos Collantes et al. present a base-editor system called Pin-point that recruits a DNA base-modifying enzyme through a hook (an RNA aptamer) within the guide-RNA molecule. In Nature Communications the goal of Lacramioara Bintu and colleagues is not base editing but epigenomic editing, the effector is a chromatin regulator and the hook is an antibody. When the CRISPR-effector combo is big, delivery of individual modules is easier. Furthermore, if the effector is already present inside the cell it can be simply recruited by providing the right hook. One more potential advantage is the convenient reconfiguration of the system by the mix and match of individual components and simultaneous recruitment of different effectors to different target sites.

TALEN vs CRISPR

Soon after the arrival of CRISPR, a report from Harvard compared the new gene-editing technique and its older sister side by side. As reported by Kevin Davies in the book “Editing Humanity,” CRISPR won convincingly, and this paper helped boost CRISPR’s popularity. This video shows that nowadays CRISPR is considered the best in terms of ease of design, ease of experimental setup, and flexibility. TALEN, however, is more precise. What about efficiency? Well, it depends. CRISPR works better in the less-tightly wound regions of the genome, but according to a recent Nature Communications paper, TALEN can access the heterochromatin region better than CRISPR. The study by Huimin Zhao and colleagues at the University of Illinois Urbana-Champaign adds to the evidence that the more (tools), the better.

Prime-edited rice & CRISPR golden rice

Do you remember prime editing? It’s the new ‘search-and-replace’ genome editing technology that mediates targeted insertions, deletions, all 12 possible base-to-base conversions, and combinations thereof. The first good news is that David Liu et al. adapted prime editors for use in rice and wheat, so don’t miss their paper in Nature Biotechnology.

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Born to kill. New CRISPR hope for fighting resistant bacteria

CRISPR evolved in bacteria as a defense mechanism against viral infections. But now researchers are turning the same weapon against bacteria themselves, hoping to defuse antibiotic resistance, which according to WHO is one of the biggest threats to global health.  

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CasX: the smaller the crispier

cas treeTime will tell if it is going to become the preferred enzyme for genome editing or just another useful tool in the expanding CRISPR kit. But the future of CasX looks bright. It is much smaller than the nucleases that have provided a foundation for this technology. Being fewer than a thousand amino acids, it offers clear advantages for delivery in comparison with Cas9, that is over 1,300 Aa. Continue reading

Lights. Camera. Action. Cut!

Super cool. The best film I’ve seen in years. I’m speechless. Over 3,000 retweets and dozens of ecstatic comments, this is how Twitter has reacted to the first real-time video featuring CRISPR, posted by Hiroshi Nishimasu of the University of Tokyo. It is not an animation clip, and it truly shows the Cas9-RNA complex paparazzed while doing its molecular job. Continue reading