Altering genes

Written by Reuters | Updated: Sep 1 2009, 05:06am hrs
Seeking ways to genetically-modify microbes to get them to do their bidding, researchers at the J Craig Venter Institute in Maryland have taken a big step toward their goal by transplanting an altered genome from one germ to another. They hope the experiment will help scientists alter bacteria to make new vaccines, clean up toxic waste and design new antibiotics. They also hope they can use the technique to try to create entirely synthetic microbes. Researchers took the entire genome out of one type of bacteria, inserted it into yeast, genetically engineered it, and then transplanted the altered gene map into another species of bacteria. Yeast is easier to manipulate in the lab and this process allowed the team to alter the genesin this case, deleting one gene not necessary for bacteria to live. They said their method might be used to tinker with the genetics of a range of bacteria that have been difficult to engineer. Many medically or industrially, important microbes are difficult to manipulate genetically. This has severely limited our understanding of pathogenesis and our ability to exploit the knowledge of microbial biology on a practical level. With their new breakthrough, researchers hope their technology could accelerate the constru- ction of live vaccine strains.

See-through display

US researchers have found a way to make large-scale flexible display screens that can be stretched to fit the contours of a bus yet are transparent enough so riders can see out windows. The thin, light screens might be used to make brake light indicators that follow the contours of a car, or health monitors or imaging devices that wrap around a patient like a blanket, said researchers at the University of Illinois. The current technology using inorganic materials produces chunky individual LED lights that need to be arranged piecemeal with a robotic arm. To solve this challenge, researchers built their LEDs on a thin layer of film later dissolved by a chemical and then affixed tiny plastic tabs on two corners to ensure the LEDs did not wash away in the chemical bath. The system works much like a rubber stamp and ink pad, using the LEDs as ink.

Sugar bug drug

Inflammatory bowel conditions like Crohns disease and ulcerative colitis affect thousands of people around the world and are notoriously difficult to treat.

However, a genetically modified bacterium that turns into a drug-delivery vehicle in the presence of a type of sugar may offer a new way to treat bowel disease, British scientists said.

The new approach uses an engineered form of Bacteroides ovatus to deliver a human growth factor called KGF-2 directly to damaged cells in the gutbut the process is only activated in the presence of xylan, a sugar that is rare in normal diet. This means patients will be able to control their medication by ingesting xylan, perhaps in the form of a drink, after swallowing the freeze-dried bacteria in capsules.

This is the first time that anyone has been able to control a therapeutic protein in a living system using something that can be eaten, said scientists at the Institute of Food Research. Going forward, the researchers aim to start clinical trials of their sugar bug drug in around 18 months, after successful tests in mice.