U.S. researchers discover how electricity moves through cells

WASHINGTON, March 12, 2010 (Xinhua) --

Researchers at the University of Minnesota in the United States have created a molecular image of a system that moves electrons between proteins in cells, according to a news release from the university.

The achievement is believed to be a breakthrough for biology and could provide insights to minimize energy loss in other systems, from nanoscale devices to moving electricity around the country.

The research, led by Carrie Wilmot, an associate professor in the College of Biological Sciences, is published in the March 12 issue of Science.

"Evolution has been fine-tuning electricity in organisms for a lot longer than humans have been using it," Wilmot says. "We can learn a lot from nature about how to use it more efficiently. This new glimpse at how the body uses electricity could lead to nanotechnology to shrink electronic circuitry even further or a more efficient grid to provide power to homes and businesses."

Energy generated by intracellular movement of electrons is the fundamental power source that enables humans to exist. As electrons move within cells, energy is channeled to create complex molecules, such as protein and DNA. These are the building materials that enable organisms to grow, maintain themselves, and store energy. Wilmot's images, obtained using x-ray crystallography, will advance the effort to understand this process better.

"Obtaining a crystal structure of a complex cellular electron transfer system is like being behind stage at a magic show," says Vernon Anderson, who oversees biochemistry grants at the U.S. National Institutes of Health's National Institute of General Medical Sciences. "We have always known there was a trick, but now the Wilmot group has provided a unique view of how this extraordinary chemical feat is accomplished."

Editor: yan

U.S. scientists discover clue of origins of vision

WASHINGTON, March 12, 2010 (Xinhua) --

By studying the hydra, a member of an ancient group of sea creatures that is still flourishing, scientists at University of California, Santa Barbara (UCSB) have made a discovery in understanding the origins of human vision, the university said in a press release. The finding was published in this week's issue of the Proceedings of the Royal Society B, a British journal of biology.

Hydra are simple animals that, along with jeSanllyfish, belong to the phylum cnidaria. Cnidarians first emerged 600 million years ago.

"We determined which genetic 'gateway,' or ion channel, in the hydra is involved in light sensitivity," said senior author Todd H. Oakley, assistant professor in UCSB's Department of Ecology, Evolution and Marine Biology. "This is the same gateway that is used in human vision."

Oakley explained that there are many genes involved in vision, and that there is an ion channel gene responsible for starting the neural impulse of vision. This gene controls the entrance and exit of ions; i.e., it acts as a gateway.

The gene, called opsin, is present in vision among vertebrate animals, and is responsible for a different way of seeing than that of animals like flies. The vision of insects emerged later than the visual machinery found in hydra and vertebrate animals.

"This work picks up on earlier studies of the hydra in my lab, and continues to challenge the misunderstanding that evolution represents a ladder-like march of progress, with humans at the pinnacle," said Oakley. "Instead, it illustrates how all organisms -- humans included -- are a complex mix of ancient and new characteristics."

Editor: Li Xianzhi