Maggie Fox, Health and Science Correspondent
WASHINGTON (Reuters) - The only researchers to publicly show that they have cloned a human embryo said on Tuesday that they had successfully repeated the experiment, growing an embryo to the 16-cell stage.
Researchers at Advanced Cell Technology of Worcester, Massachusetts, have also repeatedly created embryos using a process called parthenogenesis -- using only a human egg cell and no sperm, and without cloning.
The company says the experiments, reported in the January issue of Wired magazine, are not breakthroughs but a natural progression of its efforts to create human embryonic stem cells to use for medical treatments.
"It's not a scientific advance," ACT medical director Dr. Robert Lanza said in a telephone interview.
But he said the researchers had managed to replicate experiments reported in late 2001, in which they used cloning technology to create a human embryo that grew to the six-cell stage. They also created more advanced embryos, called blastocysts, using parthenogenesis.
http://news.yahoo.com/news?tmpl=story2&cid=570&u=/nm/20031216/sc_nm/science_clones_dc_1&printer=1