Dr. Michael West, of Advanced Cell Technology in Worcester, Massachusetts and his team have created a monkey embryo without the use of sperm that can be used to create stem cells. Through a process called parthenogenesis, stem cells were extracted from the embryo to make specialized tissues such as heart and brain material. ?These were fully developed cells that could have been used medically,? he says.
He and his colleagues used chemicals to cause a monkey egg to turn into an embryo that was allowed to grow to six cells. West says it may be possible to make human embryonic stem cells this way. Other experts say that this technique would work only with women of reproductive age who could provide the eggs and thus would not benefit males.