genetic engineering

Genetic tinkering creates obesity-resistant mice

John Carroll — Mon, 11 Aug 2008 16:07:10 -0400

A research team developed a group of transgenic mice that were unable to release a subset of GABA neurotransmitters, creating a breed of rodents that was resistant to obesity. The scientific team says the mice ate the same amount as a control group, but that they were engineered to burn energy at a much faster pace. The genetic tinkering also made the mice more resistant to the hormone ghrelin, which creates a feeling of hunger.

The researchers also helped explain the role of pro-opiomelanocortin (POMC) neurons that receive the GABA signal.

"The function of AgRP neurons is probably to reserve the energy for maintaining life," said lead study author Qingchun Tong. "So if the animal doesn't have enough food, the animal should have some strategy to preserve energy, and this group of neurons, by releasing GABA, restrains energy expenditure to maintain enough energy to survive under the conditions in which food is not readily available."

- see this report for more

Genetic engineering ‘vacuums’ Alzheimer plaque

John Carroll — Tue, 03 Jun 2008 08:41:46 -0400

A group of Yale University researchers theorized that genetic engineering used to block an immune response in cells outside the brain would accelerate the progress of Alzheimer's disease by spurring inflammation. Instead, they said, an animal study showed that the process eliminated as much as 90 percent of the amyloid plaque associated with the memory-wasting disease. "It was like a vacuum cleaner had removed the plaques." And they say there's good reason to believe that the same results will be seen in humans, paving the way to a new therapeutic approach to treat Alzheimer's.

"If results from our study in mice engineered to develop Alzheimer's-like dementia are supported by studies in humans, we may be able to develop a drug that could be introduced into the bloodstream to cause peripheral immune cells to target the amyloid plaques," said Dr Terence Town.

- read the article from the BBC

Embryo engineering breakthrough triggers criticism

Tue, 13 May 2008 06:59:59 -0400

Stem cell researchers at Cornell have genetically engineered a human embryo, a pioneering development that was immediately condemned as a big step toward designing babies. The work itself was very simple: After putting a fluorescent protein gene into an embryo all the cells in the embryo glowed after it divided, giving researchers a chance to track the changes that had been engineered. The scientists emphasized that their work was done on a nonviable embryo that could never have grown into a baby.

The work, first covered by The Sunday Times, was criticized by the Center for Genetics and Society for crossing a boundary that had never been breached. Their concern is that once researchers understand how to engineer an embryo, people can design their babies with particular attributes for appearance, intelligence or athletic ability. But the scientists say the work shouldn't be misinterpreted.

"None of us wants to make designer babies," said Dr. Zev Rosenwaks, director of the Center for Reproductive Medicine and Infertility at New York-Presbyterian/Weill Cornell Medical Center.

- read the article in the New York Times