In what is thought to be a first for the country, New York State has announced that women who donate eggs for research can be paid up to $10,000. Obtaining human eggs for research has been a huge hurdle for scientists attempting therapeutic cloning through somatic cell nuclear transfer (SCNT), the process used to create Dolly the cloned sheep. Non-binding guidelines put forth by the National Academy of Science prohibit paying women for eggs used in stem cell research. The issue--and the science--is so highly charged that most scientists working in the field have kept quiet about the details of their research, and it's unclear how many women have come forward to donate eggs thus far.

Scientists want to use SCNT to generate cloned human stem cells. In the process, the DNA from an adult cell, such as a skin cell, is inserted into a human egg that has had its DNA removed. The fertilized egg then begins to develop similarly to a regular embryo, and scientists can harvest stem cells several days later. The resulting cells are genetically matched to the adult tissue donor, and could therefore be used for cell transplants without the risk of immune rejection.

The creation of induced pluripotent stem cells (iPS cells)--a technique developed over the last few years to make stem cells from adult tissue without the use of eggs or embryos--has to some degree pushed the issue of egg donation to one side. These cells resemble embryonic stem cells in their potential to become many different types of tissue and are also genetically matched to the cell donor. But scientists say cloning is still important; they want to compare iPS cells and cloned cells, for example. In animal research, cloned stem cells have been studied much more extensively than iPS cells, which are still relative newcomers and appear to be highly variable in their ability to differentiate and self-renew.

Paying women for egg donation has been a highly controversial issue, with some opponents saying that payment will create a financial incentive for women to donate eggs. But supporters point out that women are already paid for egg donations for in vitro fertilization. Scientists working in the field say that recruiting women for egg donation--a potentially painful process with some risk--has been unsuccessful.

According to an article in the New York Times,

"There are many questions you can only answer by studying human eggs," said Dr. George Q. Daley, a stem cell researcher at Harvard and at Children's Hospital Boston. "I think it's a gold step for New York State, and it will mean a tremendous advantage for New York." Dr. Daley's research has so far used poor-quality eggs discarded after in vitro fertilization, a process he said has yielded modest returns but no stem cells.