GEN Summarizes Findings at the Fourth Annual Precision CRISPR Congress

Katy Liszewski, GEN, 15 April 2018,

Staying on top of new CRISPR developments can be simple as attending conferences. However, as that is not feasible for everyone, GEN has summarized the findings presented at the Precision CRISPR Congress.  This article covers updates in multiplexing, nanocarriers, plant breeding, and T-cell therapies.

Essential Genes Identified in Pluripotent Stem Cells

GenomeWeb, 17 April 2018,

Researchers in Jerusalem, Israel, used haploid human pluripotent stem cells and a CRISPR/Cas screen to identify essential and growth-restriction genes.  The researchers found that most of the essential genes were nuclear and mitochondrial in function.  They hope that publication of this library will reveal key aspects of cellular essentiality.

USA Will Not Regulate CRISPR-Edited Crops

Diana Kwon, 02 April 2018, The Scientist,

In a statement released on March 28 the USDA stated that they will not regulate plants that have been modified through genome editing as long as the same genotype could have been produced through traditional breeding methods.  This announcement has the potential to shave tens of millions of dollars off the cost of crop develop.

Flawed CRISPR Study Retracted

Megan Molteni, Wired Science, 02 April 2018

CRISPR has shown great promise as a therapeutic, but off-target effects remain a concern.  Last May a small case study determined that CRISPR therapeutics may lead to dangerous levels off off-target mutations, resulting in the shares of CRISPR startups plummeting.  Due to the inability of other scientists to reproduce this work, Nature Methods has retracted the paper.  This episode reveals is a genuine lack of knowledge on how CRISPR acts in cells and how many off-target effects are actually introduced.  Scientists have been working to answer these questions and develop technology to screen for off-target mutations, but to date not enough research has been completed to fully answer these questions.

CRISPR Startup and Salk Institute Both Publish on New Cas13d

Christie Rizk, GenomeWeb, 23 March 2018,

Startup Arbor Biotechnologies and the Salk Institute simultaneously published the discovery of a new class 2 enzyme dubbed Cas13d.  This new Cas system is smaller than previous Cas13 proteins and uses a single RNA guide, possibly providing for its potential development into a simpler system than the more well-known Cas9.  More research into specificity and off-target rates are needed before Cas13d is ready for widespread adoption.

Researchers Unable to Reproduce CRISPR Off-Target Problems

Kristen V Brown, Gizmodo, 05 March 2018,

In 2017, a publication raised the alarm over potential off-target effects during CRISPR therapies.  Multiple research groups set out to reproduce the study and found that the off-target effects initially reported were over-stated.  These new studies have worked to restore confidence that the CRISPR gene editing technology may be suitable for gene therapies.

CRISPR Knock Out of FREP1 Suppresses Malaria Infection in Mosquitoes

EurekaAlert! 8 March 2018,

A new study in PLOS Pathogens demonstrates that CRISPR knockout of FREP1 in Anopheles gambiae mosquitos suppressed Plasmodium parasites infections.  This could potentially be used as a gene drive mechanism to eliminate malaria infections.  The inactivation of FREP1 did result in reduced blood-feeding, lower egg hatching rate, slowed development, and reduced longevity after feeding on blood, raising concerns that the modified mosquito may not be able to compete with its wild-type counterparts.

Pig Organs Could Provide Relief to Those in Organ Failure

Alice Park, Time Magazine, 15 February 2018,

Due to limited amounts of viable donated organs, thousands of people die each year in the US waiting for a transplant.  Scientists have long desired to find a viable replacement for donated human organs and may have one in CRISPR modified pig organs.  Pig organs are roughly the same size and shape as human organs, however the presence of viruses in the pig genome have proven a significant barrier to use in clinical settings.  Now a company founded by George Church has used CRISPR to inactivate these viruses and generated 15 pigs that could be viable stocks for kidney, liver, lungs, or pancreas transplants.

Allele Specific CRISPR Editing

Sharon Begley, 02 February 2018, STAT,

Many diseases are the result of a single mutated allele.  To correct these with a CRISPR-based system, the mutated allele should be targeted while the healthy allele is left untouched.  In one of the first papers to be published in The CRISPR Journal, researchers have developed a method to target the “broken” allele while leaving the healthy allele untouched.  This proof of concept work was done in a mouse retinitis pigmentosa model, where blindness is caused by a single nucleotide change in one allele.  Results have been published on the BioRxiv prepress server (

Solving the CRISPR Delivery Problem

Megan Molteni, Wired, 26 January 2018,

Many different research groups and companies are working on the creation of CRISPR-based gene therapies. However, delivery of these therapies remains a significant obstacle.  Traditionally, gene therapies have been packaged in Adeno-associated viruses, but the size of the CRISPR machinery prevents this method of delivery.  To solve these problems, researchers are working on novel delivery mechanisms, including the use of gold nanoparticles.  Notably, a UC-Berkeley spin-off company has been created to focus solely on delivery of the CRISPR/Cas machinery.