London - Scientists have taken a major step towards creating life in the laboratory without using sperm or eggs.
By combining two types of stem cells – special cells which have the ability to develop into different kinds of tissue – from mice, researchers were able to grow a very early stage embryo.
When the collection of fewer than 100 cells, just days old, was then implanted into a womb, it triggered chemical changes that a normal pregnancy would, although it was not able to develop any further.
Lead researcher Professor Nicolas Rivron, of Maastricht University in the Netherlands, said their breakthrough could eventually create an unlimited supply of identical early-stage embryos – hollow balls of cells known as blastocysts – that could be used for infertility research and testing the effects of new medical treatments.
He added: "This is the first time we have created structures in the lab from stem cells which have the potential to form the whole organism – the baby, placenta and yolk sac. Embryos are very precious, and it is impossible to test drugs on them as you don’t have the numbers. With artificial embryos you can open up the numbers. This will allow screening of medicines in the future."