|作者：英语点津 文章来源：China Daily 点击数82 更新时间：2017/3/15 11:06:09 文章录入：刘老师 责任编辑：liu|
Artificial human life could soon be grown from scratch in the lab, after scientists successfully created a mammal embryo using only stem cells.
Cambridge University mixed two kinds of mouse stem cells and placed them on a 3D scaffold. After four days of growth in a tank of chemicals designed to mimic conditions inside the womb, the cells formed the structure of a living mouse embryo.
The breakthrough has been described as a ‘masterpiece’ in bioengineering, which could eventually allow scientists to grow artificial human embryos in the lab without the need for a sperm or an egg.
Growing embryos would help researchers to study the very early stages of human life so they could understand why so many pregnancies fail, but is likely to prove controversial and raise ethical questions about what constitutes human life.
Currently scientists can carry out experiments on leftover embryos from IVF treatments, but they are in short supply and must be destroyed after 14 days. Scientists say that being able to create unlimited numbers of artificial embryos in the lab could speed up research while potentially removing some of the ethical boundaries.
“We think that it will be possible to mimic a lot of the developmental events occurring before 14 days using human stem cells," said Professor Magdalena Zernicka-Goetz from the Department of Physiology, Development and Neuroscience at Cambridge, who led the research.
"We are very optimistic that this will allow us to study key events of this critical stage of human development without actually having to work on (IVF) embryos. Knowing how development normally occurs will allow us to understand why it so often goes wrong."
Britain is currently leading the world in fertility research, and last year a group at the Francis Crick Institute was granted permission to genetically modify human embryos, the first time in the world such a procedure had been approved by regulators.
However such work raises important ethical questions about the sanctity of human life and whether it should be manipulated or created in the lab at all.
Critics warn that allowing embryos to be grown for science opens the door to designer babies and genetically modified humans.