Featured Research

from universities, journals, and other organizations

New genome-editing platform significantly increases accuracy of CRISPR-based systems

Date:
April 25, 2014
Source:
Massachusetts General Hospital
Summary:
A next-generation genome editing system substantially decreases the risk of producing unwanted, off-target gene mutations. Researchers report a new CRISPR-based RNA-guided nuclease technology that uses two guide RNAs, significantly reducing the chance of cutting through DNA strands at mismatched sites.

A next-generation genome editing system developed by Massachusetts General Hospital (MGH) investigators substantially decreases the risk of producing unwanted, off-target gene mutations. In a paper receiving online publication in Nature Biotechnology, the researchers report a new CRISPR-based RNA-guided nuclease technology that uses two guide RNAs, significantly reducing the chance of cutting through DNA strands at mismatched sites.

"This system combines the ease of use of the widely adopted CRISPR/Cas system with a dimerization-dependent nuclease activity that confers higher specificity of action," says J. Keith Joung, MD, PhD, associate chief for Research in the MGH Department of Pathology and senior author of the report. "Higher specificity will be essential for any future clinical use of these nucleases, and the new class of proteins we describe could provide an important option for therapeutic genome editing."

Engineered CRISPR-Cas nucleases -- genome-editing tools that combine a short RNA segment matching its DNA target with a DNA-cutting enzyme called Cas9 -- have been the subject of much investigation since their initial development in 2012. Easier to use than the earlier ZFN (zinc finger nuclease) and TALEN (transcription activator-like effector nuclease) systems, they have successfully induced genomic changes in several animal models systems and in human cells. But in a previous Nature Biotechnology paper published in June 2013, Joung's team reported that CRISPR-Cas nucleases could produce additional mutations in human cells, even at sites that differed from the DNA target by as much as five nucleotides.

To address this situation, the investigators developed a new platform in which the targeting function of Cas9 was fused to a nuclease derived from a well-characterized enzyme called Fokl, which only functions when two copies of the molecule are paired, a relationship called dimerization. This change essentially doubled the length of DNA that must be recognized for cleavage by these new CRISPR RNA-guided Fokl nucleases (RFNs), significantly increasing the precision of genome editing in human cells. Importantly, Joung and his colleagues also demonstrated that these new RFNs are as effective at on-target modification as existing Cas9 nucleases that target a shorter DNA sequence.

"By doubling the length of the recognized DNA sequence, we have developed a new class of genome -editing tools with substantially improved fidelity compared with existing wild-type Cas9 nucleases and nickases (enzymes that cleave a single DNA strand)," says Joung, an associate professor of Pathology at Harvard Medical School. The research team also has developed software enabling users to identify potential target sites for these RFNs and incorporated that capability into ZiFiT Targeter, a software package freely available at http://zifit.partners.org.


Story Source:

The above story is based on materials provided by Massachusetts General Hospital. Note: Materials may be edited for content and length.


Journal Reference:

  1. Shengdar Q Tsai, Nicolas Wyvekens, Cyd Khayter, Jennifer A Foden, Vishal Thapar, Deepak Reyon, Mathew J Goodwin, Martin J Aryee, J Keith Joung. Dimeric CRISPR RNA-guided FokI nucleases for highly specific genome editing. Nature Biotechnology, 2014; DOI: 10.1038/nbt.2908

Cite This Page:

Massachusetts General Hospital. "New genome-editing platform significantly increases accuracy of CRISPR-based systems." ScienceDaily. ScienceDaily, 25 April 2014. <www.sciencedaily.com/releases/2014/04/140425162335.htm>.
Massachusetts General Hospital. (2014, April 25). New genome-editing platform significantly increases accuracy of CRISPR-based systems. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/2014/04/140425162335.htm
Massachusetts General Hospital. "New genome-editing platform significantly increases accuracy of CRISPR-based systems." ScienceDaily. www.sciencedaily.com/releases/2014/04/140425162335.htm (accessed July 28, 2014).

Share This




More Health & Medicine News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Trees Could Save More Than 850 Lives Each Year

Trees Could Save More Than 850 Lives Each Year

Newsy (July 27, 2014) A national study conducted by the USDA Forest Service found that trees collectively save more than 850 lives on an annual basis. Video provided by Newsy
Powered by NewsLook.com
Google's Next Frontier: The Human Body

Google's Next Frontier: The Human Body

Newsy (July 27, 2014) Google is collecting genetic and molecular information to paint a picture of the perfectly healthy human. Video provided by Newsy
Powered by NewsLook.com
What's To Blame For Worst Ebola Outbreak In History?

What's To Blame For Worst Ebola Outbreak In History?

Newsy (July 27, 2014) A U.S. doctor has tested positive for the deadly Ebola virus, as the worst-ever outbreak continues to grow. Video provided by Newsy
Powered by NewsLook.com
Losing Sleep Leaves You Vulnerable To 'False Memories'

Losing Sleep Leaves You Vulnerable To 'False Memories'

Newsy (July 27, 2014) A new study shows sleep deprivation can make it harder for people to remember specific details of an event. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins