The possibility of one day with unlimited quantities of human eggs for use in fertility treatments is real, according to research published in Nature by Jonathan Tilly of the Vincent Center for Reproductive Biology at Massachusetts General Hospital.
Tilly's team identified and isolated stem cells responsible for production of eggs in the ovaries during the reproductive years of women: it is DDX4 protein unique to the surface of stem cells.
Scientists identify cells grown in laboratory-generated spontaneously, immature eggs (oocytes) similar to those present in the human body, and also behave like them.
They also observed that the cells matured when they were between the tissues of a living human ovary grafted into mice. And they showed that they can be fertilized with sperm to produce embryos.
New horizons in fertility
In the U.S., approximately 10% of women (6.1 million) between 15 and 44 years of age have difficulty conceiving or maintaining pregnancy, the Centers for Disease Control and Prevention (CDC) .
For Tilly, head of research, "the primary objective of the study was to prove that stem cells exist and oocytes in ovaries of women during their reproductive lives. This opens the door to development of techniques to overcome unprecedented the infertility in women, "he said.
The researcher explains that "outside the body, these cells are more likely to multiply its generating function." He added: "If we can guide the process, I think given the possibility that in the future we will have an unlimited supply of eggs."
What number of eggs produced by a woman?
As early fetal life, are owned by 6 to 7 million eggs. From that moment, no longer produced. The vast majority of eggs that are within the ovaries steadily die, until they are exhausted at menopause.
The Cleveland Clinic reports that at birth, there are approximately 1 million eggs and at the time of puberty, only be 300,000. Of these, only between 300 and 400 will be ovulated during the reproductive life course of women.
In the phase of the study of human samples, cultured stem cells in vitro and found that they differed from others that showed genetic patterns such as oocytes and had half the genetic load (23 chromosomes instead of 46) , exactly as gametes.
Furthermore, some marked stem cells implanted under the skin of rodents and these gave rise to immature human follicles.
According to Tilly, these results constitute the "proof of concept that stem cells ovocíticas, reintroduced in the adult human ovarian tissue, play the role expected to generate new oocytes are surrounded by host cells to form new hair follicles."
Could potentially lead to eggs and these form viable embryos, which have many applications in the field of assisted reproduction .
