First Road Map of Human Sex-Cell Development
The causes of infertility, which affects around 10% of couples, are often unknown, but may in some cases result from the body’s inability to produce viable gametes — also known as sperm and egg cells. The first study of the development of such ‘germ cells’ from humans could help scientists to learn how to create them in the laboratory instead.
Even though the reproductive age for humans is around 15–45 years old, the precursor cells that go on to produce human eggs or sperm are formed much earlier, when the fertilized egg grows into a tiny ball of cells in the mother’s womb. This ball of cells contains ‘pluripotent stem cells’ — blank slates that can be programmed into any type of cell in the body — and researchers are hoping to use these stem cells to treat various conditions, including infertility. In a Nature Cell Biology paper, researchers trace the development of early germ cells in human fetuses of between 6 to 20 weeks and analysed when genes were turned on or off.