The first ES cell lines were established from mice in 1981 by Martin Evans of Cardiff University, UK, who was last year awarded the Nobel Prize in Medicine or Physiology. Researchers have long been working on establishing rat ES cells, but faced technical hurdles because the conventional methods developed for the derivation of mouse cells did not work in rats.
Building on recent research into how ES cells are maintained, the USC researchers found that rat ES cells can be efficiently derived and grown in the presence of the "3i medium," which consists of molecules that inhibit three specific gene signaling components (GSK3, MEK and FGF receptor kinase). This approach insulates the stem cell from signals that would normally cause it to differentiate, or turn into specialized types of body cells. By blocking these signals, Ying and colleagues found that stem cells from rats, which have previously failed to propagate at all, could be grown indefinitely in the laboratory in the primitive embryonic state.
An accompanying study led by researchers at the University of Cambridge, U.K., reported similar findings, independently verifying that authentic ES cells can be established from rats. Both papers will be published in the upcoming issue of Cell.
"The development of rat embryonic stem cells, long sought by researchers around the world, is a major advance in biomedical science," says Martin Pera, Ph.D., director of the Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research at USC. "These new stem cell lines will make a huge contribution to basic and applied research and drug development, by providing a technology platform for facile genetic manipulation of a mammalian species that is widely used in academic and industrial labs studying physiology, pathology and pharmacology."
Until now, authentic ES cells have never been establis
|Contact: Sara Reeve|
University of Southern California