They create artificial human embryos without the use of eggs and sperm.

The use of embryos in research has many advantages. This may help to better understand how we develop, since we are formed by the union of two sex cells or better understand certain diseases. It also serves to study the causes that lead to abortions or malformations, For example. But, of course, for ethical reasons, this investigation is governed by many rules. For this reason, some scientists have focused their work on obtaining synthetic embryos with the same benefits, but which do not form naturally.

This has already been done with laboratory animal models. And in the case of humans, some attempts have been made. However, things never went as far as the team scientists from the University of Cambridge and the California Institute of Technology.

In their case, they obtained synthetic human embryos by stem cell programming. In addition, for the first time in our species, they managed to develop cells three different kinds. That is, they specialize in three different areas. It may have great applications; although, not even in the case of normal embryos, it may be necessary to establish new rules to fill the ethical gap that exists in this regard.

Synthetic or natural embryos, how are they obtained?

Humans reproduce with sexual reproduction. It means that egg and spermwhich are male and female sex cells, merge to form zygoteor in a process known as fertilization. It begins to divide little by little, giving rise to an increasing number of cells that first appear in one sheet and then become specialized. different cell lines. In addition, little by little the axes are established, which will give rise to each of the parts of the body of a new individual.

This is what is known as embryonic development and is the natural process by which embryos are born.

Embryo cells are known as pluripotent stem cells. That is, they have the ability to divide into more stem cells or differentiate into any type of cell. This is very helpful in regenerative medicine, as it helps to get any type of cells to repair damaged adult cells. But it also has other uses, such as obtaining new embryos without re-fertilization.

This is how those responsible for this new investigation received their synthetic embryos. They took cells from a part of the embryo called the embryonic stem and programmed them not to produce differentiated adult cells, but to step back and create a new embryo early in its development.

Thus, as the principal investigator explained, Magdalena Zhernitskaya-Goetzat the annual meeting of the Society for Stem Cell Research, allowed them to obtain synthetic embryos that continued to develop beyond 14 days.

Why is there a 14 day limit?

Obtaining embryos in the laboratory is not difficult. In fact, it is done daily in clinics. Assisted reproduction. However, the legislation of the vast majority of countries does not allow the development of these embryos outside the uterus for more than 14 days. This is done because of the ethical implications of getting people into such artificial.

However, there is a legal vacuum as to what happens if it is not a naturally occurring embryo. eggs and sperm. These scientists managed to obtain synthetic embryos, representing the stages after 14 days of development. There was no beating heart, no rudimentary brain, but there were cells that would give rise to placenta, yolk sac and embryo itself. Thus, these synthetic embryos can be very useful in analyzing how certain environmental factors affect the embryo, without the need to monitor the pregnancy.

Now what?

Before talking about what the development of synthetic embryos might entail, it should be borne in mind that this study not published yet. The procedure may be recognized as erroneous or cannot be reproduced. For this reason, for the time being, we must speak of this subject with caution.

Now, if things go the way Zernitska-Goetz described, questions about the next step will have to be asked. How far can you go? Is it possible to reach the last stages of embryonic development outside uterus?

For now, there are researchers who have gone further with animal models. For example, with mice he succeeded in reaching a beating heart and the beginnings of a developing brain. However, it does not appear that with current technology, synthetic embryos can reach the final stages of development. As explained in GuardianLast April, a team of Chinese scientists developed synthetic embryos from monkey cells and implanted them into the uterus of adult female monkeys. Thus, some of them showed signs of pregnancy, but only for a few days. Then everyone had a miscarriage very early.

That’s why, It doesn’t look like it’s technically possible.. Or maybe it’s a biological problem. One thing is clear: if the investigation continues, it may be necessary to change the legislation. After all, when it comes to human embryos, bioethics must be taken into account.