According to this New Scientist report, scientists at University of Newcastle-upon-Tyne in the UK had turned bone marrow stem cells into primitive sperm cells. They obtained bone marrow stem cells from four adult men who were about to undergo bone marrow transplantation and turned them in cells that are precursors of human sperm cells. So what does that mean? Scientist believe, although it is just the start, one day we might be able to turn them into functioning sperm cells, thus helping infertile couples having babies. They even think it might be possible for women to produce their own sperm cells, making it possible for lesbian couples to have children. However, the biggest obstacle is to turn these primitive sperm cells into real functioning cells, and that will take a long time to be successful.