In what could be a major breakthrough for fertility treatment, unlimited egg supply for women may be a step closer following new stem cell research.
The study, published in the journal Nature Medicine, challenges the long-held belief that women are born with a finite supply of eggs that will be exhausted by menopause.
Scientists isolated stem cells in the ovaries of reproductive age women and found they can produce immature eggs (oocytes) in laboratory conditions – and further tests on mice revealed the eggs could be fertilised.
The study is not the first to dispute the notion that a woman’s egg supply is gradually depleted, running out by middle age.
Lead researcher Dr Jonathan Tilly, from Massachusetts General Hospital, first questioned this theory in 2004 in a study that revealed mice have some egg-producing stem cells.
Dr Tilly said: “The primary objective of the current study was to prove that oocyte-producing stem cells do in fact exist in the ovaries of women during reproductive life, which we feel this study demonstrates very clearly.”
Researchers found the stem cells, which go on to produce oocytes, by searching for a protein that is unique to the surface of the stem cells.
Oocytes are immature female sex cells that mature to give rise to a fully mature egg cell.
The researchers grafted human ovarian tissue around the stem cells inside mice and found they “spontaneously generated” egg cells that looked and acted like oocytes. Read the rest of this entry »