Dr. Jun Wu at the University of Texas’ Southwestern Medical Center at Dallas created hollow spheres of cells that are very similar to embryos at the stage when they are usually implanted in the womb, known as blastocysts. The new embryos made in the laboratory were called “blastoids”. UT Southwestern Medical Center hide caption
UT Southwestern Medical Center
UT Southwestern Medical Center
For decades, science has tried to solve the riddles of how a single cell becomes a fully educated human and what goes wrong to cause genetic diseases, miscarriages, and infertility.
Now scientists have created living things in their laboratories that resemble human embryos. The results of two new experiments are the most complete such “model embryos” that have been developed to date.
The aim of the experiments is to gain important insights into early human development and to find new ways to prevent birth defects and miscarriages and to treat fertility problems.
However, the research, published in two separate articles in Nature Portfolio on Wednesday, raises sensitive moral and ethical concerns.
“I’m sure it makes anyone morally serious nervous when people start creating structures in a Petri dish that are so close to being early humans,” says Dr. Daniel Sulmasy, bioethicist in Georgetown.
“They’re not quite there yet, and that’s a good thing. But the more they squeeze the envelope, the more nervous, in my opinion, everyone gets that people are trying to create people in a test tube,” says Sulmasy.
Crucial periods of embryonic development are hidden in the body of women during pregnancy and therefore inaccessible. Conducting experiments on human embryos in the laboratory is difficult and controversial.
“We know a lot about animals like mice and rats. But not much about people,” he says Jun Wu, a molecular biologist at the University of Texas’ Southwestern Medical Center at Dallas who led one of the two research teams publication the results of the new experiments. “It really is a black box.”
This is how scientists have started in recent years Creation of structures that resemble human embryos in the laboratory through the use of chemical signals Getting cells to form into entities that looks like very primitive human embryos.
Well, Wu’s team and another international team of scientists have gone further than ever. They formed hollow spheres of cells that are very similar to embryos at the stage they normally implant in the uterus, known as blastocysts. The new embryos made in the laboratory were called “blastoids”.
“We’re very excited,” says Jose Polo, developmental biologist at Monash University who led the second experiment. “With this technique we can now make hundreds of these structures. In this way we can expand our understanding of very early human development. We think this will be very important.”
Some other scientists applaud the research.
“I would consider this a huge step forward in this area,” he says Jianping Fu, Ann Arbor, a professor of mechanical engineering at the University of Michigan, wrote one Commentary on research. “This is truly the first complete model of a human embryo.”
The blastoids appear to be sufficiently different from naturally formed embryos to prevent them from ever becoming a viable fetus or baby. But they seem very close.
“Which then raises a very interesting question as to when an embryo model is a real embryo,” says Insoo Hyun, bioethicist at Case Western Reserve University and at Harvard.
The two experiments started with different cells to get similar results. Wu’s group created its blastoids from human embryonic stem cells and from “induced pluripotent stem cells” made from adult cells. Polo’s group started with adult skin cells.
“This work is absolutely disturbing for a lot of people because it really challenges our tidy categories of what life is and when life begins. That’s what I call the biological-metaphysical time machine,” says Hyun.
Hyun agrees that the research is very important and could lead to many other advances. However, according to Hyun, it is important to establish clear guidelines on how scientists can be allowed to responsibly conduct this type of research.
Hyun is in favor of revising a guideline known as the 14-day rule, which prohibits experiments on human embryos in the laboratory beyond two weeks of its existence. According to Hyun, exceptions should be allowed under certain carefully verified conditions.
“I think it should be done gradually on a case-by-case basis,” says Hyun. “I’m not in favor of having a complete free-for-all. I think it should be carefully thought out here and there for exceptional cases.”
However, others are concerned about the relaxation of the 14-day rule.
That could mean, “We could just keep growing these types of people in a test tube and not even consider the fact that they’re so close to being human, right?” says Kirstin Matthews, Science and Technology Policy Fellow at Rice University. “I guess I watch too much science fiction because I find it really annoying.”
In fact, another team of scientists at the Weizmann Institute of Science in Israel discovered how mouse embryos can be grown outside of the womb – a step towards creating an “artificial womb” Report published Wednesday in the journal Nature.