Researchers supported by the National Institutes of Health have for the first time activated mouse egg cells at the earliest stage of their development and brought them to maturity. In a related experiment, the researchers replicated the finding by also bringing human eggs to maturity in the laboratory.
Current infertility treatment techniques stimulate immature eggs so they develop to the stage at which the eggs can be fertilized, but these techniques work only on eggs at a comparatively late stage of development. These later-stage eggs are few in number and much more difficult to recover than the early-stage eggs used by the researchers in this study.
Using the new technique, the researchers brought dormant mouse eggs to full maturity within the laboratory. The eggs then were fertilized and transferred into female mice, which carried them to term.
The human eggs were not fertilized. The technique is still in its early stages, has not been sufficiently studied for human use and will require several more years of study.
According to the researchers, one day this technique could be used to treat female infertility, particularly forms of infertility in which the supply of available eggs is diminished or limited. Similarly, the technique could be combined with efforts to bank the ovarian tissue of women in need of cancer therapy that might cause infertility.
"The researchers have developed a promising new technique that may someday provide additional options for women seeking treatment for certain forms of infertility," said Alan E. Guttmacher, M.D., director of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), the NIH Institute that funded the study.
The findings appear online in the Proceedings of the National Academy of Sciences.
First author Jing Li conducted the research with Stanford University colleagues Yuan Cheng, Cynthia Klein and Aaron J.W. Hsueh; Kazuhiro Kawamura of Akita University; and Shuang Liu, Shu Liu and En-Kui Duan of the Chinese Academy of Sciences.