An Israeli team led by Jacob Hanna has created the first artificial human embryo and kept it outside the womb for 14 days. A key figure. Two weeks is exactly the point at which the embryo is considered a human being with appropriate legal protection on a legal, bioethical, and scientific level. The study was published in the journal Nature.
The article was published in bioRxiv, a scientific repository, in July but did not have the review of other researchers at the time. The Nature article already includes these revisions.
The team built on previous research using synthetic mouse embryo models generated from stem cells. The scientists emphasize that neither fertilized eggs nor embryos were implanted in the uterus. They are embryos created from stem cells capable of producing any type of cell.
On the 14th day, the development of the embryonic cells into humans begins, which is closely linked to the connection to the mother and provides nourishment and protection for the following weeks. Although these embryos have been outdoors for 14 days, their condition corresponds to day 7 of a natural human embryo when it is implanted in the uterus.
Light in early stages of embryonic development
Extra-embryonic tissue is essential for the development of the embryo. The synthetic embryos in the study had all the characteristic structures and compartments of the first few weeks, including the placenta, yolk sac, and other external tissues.
Its structure resembles that of natural embryos, but not quite. However, the scientists argue that “the preserved human embryo models may provide an unprecedented opportunity for molting.” New light on the mysterious beginnings of the embryo,” said a statement from the Weizmann Institute of Sciences (Israel), the authors of the program.
After conception, the cells, which are implanted in the uterus seven days later, develop into a well-formed embryo with its organs within three weeks. “The first month is still largely a black box,” says Hanna. The study aims to unravel the mystery of the first month, when a large proportion of underdeveloped pregnancies are lost and pathologies and congenital defects develop. Therefore, the model “allows an ethical and accessible look into this ‘box’, mimicking the development of a real human embryo almost identically,” they argue.
