It is the first time researchers have applied methods developed in the Seoul laboratory to nonhuman primate eggs. Resulting cloned embryos progressed to the blastocyst stage, a developmental step in which the embryo resembles a hollow, fluid-filled cavity surrounded by a single layer of cells. Called the inner cell mass, this layer contains embryonic stem cells. Growth of a cloned nonhuman primate egg to the blastocyst stage is farther along the developmental spectrum than ever achieved before, Gerald Schatten, Ph.D., director of the Pittsburgh Development Center at Magee-Womens Research Institute, and his colleagues report.
Calvin Simerly, Ph.D., associate professor of obstetrics, gynecology and reproductive sciences at the University of Pittsburgh School of Medicine and the study's first author, will present the findings on Dec. 6 at Cell Biology 2004, the 44th annual meeting of the American Society for Cell Biology. Scientific sessions are Dec. 4 to 8 at the Washington Convention Center in Washington, D.C.
"We've made improvements by adapting some of the Korean methods and have been able to overcome some of the hurdles we were seeing before," said Dr. Schatten, senior author of the study and professor of obstetrics, gynecology and reproductive sciences and cell biology and physiology in Pitt's School of Medicine. "This is a significant step forward and gives us hope for eventually being able to derive embryonic stem cells through therapeutic cloning."
In therapeutic cloning, limited cell division is induced in an unfertilized egg cell to produce embryonic stem cells. In reproductive cloni