A Look Inside Synthetic Human Embryos
Reproduction is one of the most important mechanisms for survival for all species, and humans are no exception. Infertility, defined as the inability to achieve pregnancy after a year of trying, currently affects 1 in 6 couples globally. Causes could be anything from genetics to lifestyle choices to pollutant exposures. Recently, scientists have created lab-engineered embryos that may be the key to better understanding human development.
The embryo model is a mass of cells created from stem cells that mimic the same properties that real embryos exhibit. This model allows scientists to study human development beyond the first week. Specifically, researchers hope to learn more about the stage where an embryo implants in the uterus. About 60% of pregnancies fail at this stage, so the model embryos serve as a tool to gain insight into the earlier stage of human development.
The models are also helpful since real embryos are in short supply for scientists to study. Donated human embryos are unique, and when researchers come across them, they are limited in the types of experiments and procedures they can conduct.
An image of a developing embryo.
Real embryos are typically only stored for 14 days within a lab due to bioethical concerns. However, implantation within the uterus occurs anywhere from 17 to 21 days after conception, resulting in this stage of pregnancy lacking research and understanding. Following this period of time, scientists use pregnancy scans to learn more about later stages of development. The synthetic models hope to fill a crucial knowledge gap when it comes to the growth of an embryo.
The model embryos are grown from a single stem cell. This stem cell began reproducing and eventually reached gastrulation, a crucial point in embryonic development. From here, the many cells began to form distinct cell lines and started to fill out the basic axes of the body. This embryonic model had previously been successful when mouse stem cells were used. Still, scientists from the University of Cambridge and the California Institute of Technology were the first to succeed in a model made out of human stem cells.
Many ethical and legal concerns have been raised about the possible uses of synthetic embryos. Many question whether it's moral for a synthetic embryo to be implanted in a woman's uterus. This procedure would also be illegal in many countries around the world. That being said, it's important to keep in mind that the model was not created for the purpose of inducing pregnancy. Instead, scientists hoped to create a synthetic embryo that would allow them to understand early human development further. With further research, model embryos could help scientists discover what drives early embryonic development, a discovery that could help start many families across the world.
