Japanese and U.S. researchers have transplanted human ovary tissue into rats and reported that the tissue showed early signs of being able to produce eggs, a Japanese doctor said Tuesday.
The experiment, conducted jointly by the Asahikawa Medical College and the University of Utah, could theoretically lead to the cultivation of human eggs for in vitro fertilization, according to Akiyasu Mizukami of the medical college in Hokkaido.
"Although there are ethical issues involved, it is possible that the future will see the practical application of human egg banks," he said, suggesting that the development could be a boon for people suffering from infertility.
The experiment, conducted at the U.S. university, was the first time scientists have developed human ovaries in the bodies of another species.
The ovary tissue was taken from three U.S. women, according to Mizukami. The tissue was cut into small pieces and injected into the rats' abdomens.
The rats were then injected with a growth-promoting hormone for two to three weeks, during which the researchers began to observe signs of the ovaries' growth.
That was followed by the first stage of the development of egg sacs.
The researchers terminated the experiment at that point. They said it would have taken around 90 days for the eggs to fully mature.
Mizukami plans to announce the results of the experiment at a meeting of the Japan Society of Obstetrics and Gynecology that opens in Tokushima Prefecture on April 1.