Scientists develop world's first 'synthetic embryos', bypassing need for sperm, eggs and fertilisation
In a ground-breaking achievement, scientists produced the first "synthetic embryos" in the world without the need for sperm, eggs, or fertilisation. Researchers at the Weizmann Institute in Israel discovered that it was possible to get mouse stem cells to self-assemble into structures that resembled early embryos and had an intestinal tract, a developing brain, and a beating heart. The live constructs, often referred to as synthetic embryos because they are made without fertilised eggs, are anticipated to advance our understanding of how organs and tissues develop throughout the growth of natural embryos in the near future.
The breakthrough, however, may also lessen the use of animals in experiments and eventually open the door to new supplies of cells and tissues for use in human transplants, according to researchers. For instance, a leukaemia patient's skin cells might possibly be changed into bone marrow stem cells to treat their illness. The same team reported how they had created an artificial womb that allowed real mouse embryos to develop outside the uterus for a few days last year. In the most recent study, the same apparatus was used to grow mouse stem cells for more than a week—nearly half the duration of a mouse's gestation.
While some of the cells underwent chemical pretreatment to activate genetic programmes that would cause them to develop into the placenta or yolk sac, other cells naturally underwent organ and other tissue development. While the majority of stem cells failed to develop into structures resembling embryos, 0.5% of them united to create tiny balls that gave rise to unique tissues and organs. The internal structure and cell genetic profiles of the synthetic mouse embryos were 95% identical to those of real mouse embryos. The scientists could detect that the developing organs were useful.
The UK's Human Fertilization and Embryology Act does not apply to the manufacture of "synthetic" human embryos, but since they are not considered "permitted embryos," using them to induce pregnancy in a woman would be illegal.