Subscribe free to our newsletters via your
. Solar Energy News .




INTERN DAILY
Powerful tool for genetic engineering
by Staff Writers
Braunschweig, Germany (SPX) Nov 26, 2013


Streptococcus pyogenes is one of the bacteria in which the HZI scientists have studied the CRISPR-Cas system. Image courtesy HZI / M. Rohde.

Viruses cannot only cause illnesses in humans, they also infect bacteria. Those protect themselves with a kind of 'immune system' which - simply put - consists of specific sequences in the genetic material of the bacteria and a suitable enzyme. It detects foreign DNA, which may originate from a virus, cuts it up and thus makes the invaders harmless.

Scientists from the Helmholtz Centre for Infection Research (HZI) in Braunschweig have now shown that the dual-RNA guided enzyme Cas9 which is involved in the process has developed independently in various strains of bacteria. This enhances the potential of exploiting the bacterial immune system for genome engineering.

Even though it has only been discovered in recent years the immune system with the cryptic name 'CRISPR-Cas' has been attracting attention of geneticists and biotechnologists as it is a promising tool for genetic engineering. CRISPR is short for Clustered Regularly Interspaced Palindromic Repeats, whereas Cas simply stands for the CRISPR-associated protein.

Throughout evolution, this molecule has developed independently in numerous strains of bacteria. This is now shown by Prof Emmanuelle Charpentier and her colleagues at the Helmholtz Centre for Infection Research (HZI) who published their finding in the international open access journal Nucleic Acids Research.

The CRISPR-Cas-system is not only valuable for bacteria but also for working in the laboratory. It detects a specific sequence of letters in the genetic code and cuts the DNA at this point. Thus, scientists can either remove or add genes at the interface. By this, for instance, plants can be cultivated which are resistant against vermins or fungi. Existing technologies doing the same thing are often expensive, time consuming or less accurate.

In contrast to them the new method is faster, more precise and cheaper, as fewer components are needed and it can target longer gene sequences.

Additionally, this makes the system more flexible, as small changes allow the technology to adapt to different applications. "The CRISPR-Cas-system is a very powerful tool for genetic engineering," says Emmanuelle Charpentier, who came to the HZI from Umea and was awarded with the renowned Humboldt Professorship in 2013.

"We have analysed and compared the enzyme Cas9 and the dual-tracrRNAs-crRNAs that guide this enzyme site-specifically to the DNA in various strains of bacteria." Their findings allow them to classify the Cas9 proteins originating from different bacteria into groups. Within those the CRISPR-Cas systems are exchangeable which is not possible between different groups.

This allows for new ways of using the technology in the laboratory: The enzymes can be combined and thereby a variety of changes in the target-DNA can be made at once. Thus, a new therapy for genetic disorders caused by different mutations in the DNA of the patient could be on the horizon.

Furthermore, the method could be used to fight the AIDS virus HIV which uses a receptor of the human immune cells to infect them. Using CRISPR-Cas, the gene for the receptor could be removed and the patients could become immune to the virus. However, it is still a long way until this aim will be reached.

Still those examples show the huge potential of the CRISPR-Cas technology. "Some of my colleagues already compare it to the PCR," says Charpentier. This method, developed in the 1980s, allows scientists to 'copy' nucleic acids and therefore to manifold small amounts of DNA to such an extent that they can be analysed biochemically. Without this ground-breaking technology a lot of experiments we consider to be routine would have never been possible.

Charpentier was not looking for new molecular methods in the first place. "Originally, we were looking for new targets for antibiotics. But we found something completely different," says Charpentier. This is not rare in science. In fact some of the most significant scientific discoveries have been made incidentally or accidentally.

Ines Fonfara, Anais Le Rhun, Krzysztof Chylinski, Kira Makarova, Anne-Laure Lecrivain, Janek Bzdrenga, Eugene V. Koonin, Emmanuelle Charpentier; Phylogeny of Cas9 determines functional exchangeability of dual-RNA and Cas9 among orthologous type II CRISPR-Cas systems; Nucleic Acids Research, 2013, DOI: 10.1093/nar/gkt1074.

.


Related Links
Helmholtz Centre for Infection Research
Hospital and Medical News at InternDaily.com






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle








INTERN DAILY
US orders startup to halt DNA analysis kit sales
Washington (AFP) Nov 25, 2013
US health officials have ordered a startup headed by the ex-wife of a Google co-founder to halt a service of DNA testing to determine health risks. The Food and Drug Administration said in a warning letter made public Monday to the company, 23andMe, that its "saliva collection kit and personal genome service" needs to get regulatory approval. The company was co-founded by Anne Wojcicki, ... read more


INTERN DAILY
Microbiologists reveal unexpected properties of methane-producing microbe

Direvo completes lab scale development of low cost lactic acid production

Scripps Oceanography Researchers Engineer Breakthrough for Biofuel Production

Let's just harvest invasive species and the problem is solved

INTERN DAILY
Spanish scientists are designing a robot for inspecting tunnels

Penguin-inspired propulsion system

Artificial heart to pump human waste into future robots

Quantum world record smashed

INTERN DAILY
Small-Wind Power Market to Reach $3 Billion by 2020

Siemens achieves major step in type certification for 6MW Offshore Wind Turbine

IKEA invests in Canadian wind project

High bat mortality from wind turbines

INTERN DAILY
Volvo signs second loan with China Development Bank

France's Renault and Peugeot seen to profit from Iran deal

Nissan says struggling to satisfy China growth

Toyota strikes first-ever hybrid parts sharing deal in China

INTERN DAILY
Chevron alleges Ecuador fraud in oil pollution case

Iran deal 'will lead to surge of oil to Asia'

JPL to Assist in Oil and Gas Tech Development

Optimizing electronic correlations for superconductivity

INTERN DAILY
Pakistan launches largest nuclear power project

AREVA and Wroclaw University of Technology sign memorandum of understanding

Romania, China ink nuclear cooperation agreements

UN nuclear watchdog in Japan for Fukushima review

INTERN DAILY
World's top carbon emitter China expands emissions trading

Are Canadian Energy Stocks Set for a Rebound?

Climate: Gloves off between EU, developing countries

Oettinger reassures Norway on undersea grid link to Britain

INTERN DAILY
VTT introduces deforestation monitoring method for tropical regions

Philippines to plant more mangroves in wake of Typhoon Haiyan

Rising concerns over tree pests and diseases

Bait research focused on outsmarting destructive beetle




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement