Israeli researchers have created a 14-day human embryo model without the use of gametes. An advance that should make it easier to conduct research on embryos, which is often confronted with ethics.
A 14-day-old embryo created without sperm, eggs and uterus. Although this may seem futuristic, this scientific advance was actually achieved by Israeli researchers at the Weizmann Institute.
“This is the first embryo model to show structural organization of compartments and morphological similarity to a human embryo at day 14,” said Professor Jacob Hanna, who led the study, published this week in the journal Nature. Wednesday, on the BBC.
The goal? To be able to intensify research into the first moments of human life, which are still poorly understood by scientists, without resorting to human embryos. This raises legal, ethical and technical problems.
“It’s a black box, and it’s not a cliché: our knowledge is very limited,” the professor added to British media.
Enabling advances in fertility or disease
More specifically, this would be used to investigate hereditary and genetic diseases, to prevent miscarriages, to improve the success rates of in vitro fertilization or to test the compatibility of medications with pregnancy.
For example, this study would have already made it possible to find out that certain parts of the embryo are not formed if the first cells of the placenta do not surround it.
To achieve this embryo model, which visually resembles that of a 14-day-old human, the researchers started with stem cells that can transform into different cell types. And therefore to recreate the four types of cells that are present in the early stages of the human embryo.
Of the 120 mixed stem cells, about 1% began to assemble spontaneously. However, this leads to a 99% failure.
Development of this model embryo was limited to 14 days, which is the legal limit for human embryo research in many countries.
An “embryo model” compatible with pregnancy?
If this scientific advance aims to overcome an ethical problem, it raises another question: would it be possible to achieve pregnancy using these embryo models?
The answer is no. “This embryo model would not be able to develop if transferred into the uterus because it bypasses the necessary step of attachment to the uterine wall,” said Dr. Peter Rugg-Gunn, who studies embryonic development at the Babraham Institute in the United Kingdom, told the Guardian.
However, the latter stressed that this work and other similar studies “raise important ethical considerations” and are subject to “in-depth assessment and discussion” at the international level.
Professor James Briscoe of the Francis Crick Institute, who was interviewed by the BBC ahead of this study, agrees. In his opinion, scientists must “proceed with care, caution and transparency” to avoid a “chilling effect” on the public.