Social Media Sidebar

Announcement

Please sign up, comment on articles and bring your friends!

Current poll

PlanetTech is asking:

What do you think about our new web site?

Love it, indeed
Really good solution
Same as old one
The old one was better
This is a new option

Quote of the day

People say we're running out of energy. That's only true if we stick with these old 19th century technologies. We are awash in energy from sunlight.

 

Ray Kurzweil

 

Cas9 molecule points the way to viral delivery of CRISPR genome editing

RATE THIS! +28
Posted in Science on 4th Apr, 2015 07:04 PM by AlexMuller

Derived from a natural defense mechanism of bacteria, the CRISPR genome editing system uses a class of proteins called Cas9 to engineer precise cuts in cellular DNA, making it possible for scientists to flexibly delete or insert genes nearly anywhere in the genome.

 
There are obstacles to using CRISPR in living organisms, however, and perhaps the biggest is the problem of delivering Cas9 to cells in the body. The most popular vector for gene therapies, in which new DNA sequences are inserted into the human genome to combat the effects of disease-causing mutations, has long been the adeno associated virus (AAV), which can deliver a genetic payload to a single, well-defined region of the genome without noticeable side effects.
 
However, AAV vectors have been largely unavailable to CRISPR scientists, because these viruses can only carry payloads up to a certain size, and a standard Cas9 system, including the Cas9 molecule itself and multiple guide RNA sequences to direct Cas9 to its DNA target, comes in over the limit.
 
Today, a paper in Nature demonstrates a way around this limitation, successfully engineering genetic changes in mice using an AAV-delivered CRISPR system. The work comes from the lab of Feng Zhang, of the Broad Institute of MIT and Harvard, who first demonstrated that CRISPR genome editing could be performed in mammalian cells in 2013.
 
Almost all scientists using CRISPR today choose to use a Cas9 molecule derived from the bacterium Streptococcus pyogenes. “The reason the S. pyogenes has been used as the standard is because it was the only Cas9 that was very reliable, in terms of efficiency, and also had a broad targeting range,” explains Le Cong, co-lead author of the new paper and a postdoctoral researcher at the Broad Institute. (His fellow lead author, Fei Ann Ran, presented some results from this paper at the Molecular Medicine Tri Conference this February.)
 
The efficiency refers to how reliably the Cas9 molecule cuts both strands of DNA at a targeted site, while the targeting range refers to how many potential regions of the genome the molecule can interact with. All Cas9 molecules need to make cuts next to specific PAM (protospacer-associated motif) sequences, but the S. pyogenes Cas9 uses the PAM sequence NGG, which is so common across the genome that it can in effect be targeted almost anywhere.

Tags: DNAgeneticsCRISPRCas9biologychemistrymedicine

Read original article » Back to category

Comments

Author: Guest
Posted: 2015-04-05
+1
Cas9 CRISPR revolution is going to make enormous difference to how we do research and will quickly find a broad range of applications even reaching the clinic Reply
Author: Guest
Posted: 2016-05-06
+0
Damn, I wish I could think of soenmhitg smart like that! Reply


 

Recent headlines

  • Posted in Business on 2017-09-21 08:16:42
    Google signs $1.1bn HTC smartphone deal..read more
    Posted in Business on 2017-09-21 08:11:40
    US solar plant costs fall another 30 per cent in just one.....read more
    Posted in Science on 2017-09-21 08:04:25
    SpaceX will call global internet satellite network Starlink..read more
    Posted in Software on 2017-09-20 19:05:15
    Google boosts Cloud Natural Language API with automatic.....read more
    Posted in Software on 2017-09-20 18:55:34
    Salesforce to launch $50 million artificial intelligence.....read more
Posted in Business on 2013-10-10 01:33
China is working towards a manned lunar mission in about.....read more
Posted in Business on 2013-10-20 07:17
Spacex says China is their main competitor for commercial.....read more
Posted in Software on 2013-10-20 06:43
Pirate Bay Browser Clocks 1,000,000 Downloads..read more
Posted in Medicine on 2013-10-10 02:10
Google reportedly investing hundreds of millions into new.....read more
Posted in Medicine on 2013-10-14 03:13
Endothelial Cells Can Repair and Regenerate Organs,.....read more
Posted in Science on 01.01.2010
Spacex says China is their main competitor for commercial.....read more
Posted in Science on 01.01.2010
Staring at Your Phone Could Be Making You Short Sighted..read more
Posted in Science on 01.01.2010
Oculus Rift virtual reality headset coming to mobile, but.....read more
Posted in Science on 01.01.2010
China is working towards a manned lunar mission in about.....read more
Posted in Science on 01.01.2010
Delivering drugs via nanoparticles to target mitochondria..read more

Recent Blog Posts

  • Posted by AlexMuller
    Scientists probe Neptune's depths to reveal secrets of icy.....read more
    Posted by AlexMuller
    New terahertz imaging approach could speed up skin cancer.....read more
    Posted by AlexMuller
    Rebutting the claim that antidepressants do not work..read more
    Posted by AlexMuller
    Artificial neural networks decode brain activity during.....read more
    Posted by AlexMuller
    Four Earth-sized planets detected orbiting the nearest.....read more

Login to your Account

Login to your PlanetTech Account here

Username:
Password:
Remember me
or

Create a New Account

You just need username and password

The following errors occured:
Username:
Email:
Password:
Verify password:
Remember me