Exploring the Possibilities of Synthetic Embryos Created Using Stem Cells
Key Highlights :
Stem cell research has made incredible advances in recent years, and has now made it possible to create synthetic embryos without a sperm or an egg. This breakthrough was reported by The Guardian, and the model embryos created in the laboratory resemble natural embryos in the earliest stages of human development.
Researchers believe that these synthetic embryos could help scientists understand the impact of genetic disorders and the biological reasons behind recurrent miscarriages. However, the entities grown in the laboratory fall outside current legislation in the United Kingdom and most other countries, which raises serious ethical and legal issues.
Stem cells are cells that can regenerate or develop into many different types of specialised cells in the body, such as muscle cells, blood cells and brain cells, serve as a repair system for the body, and can divide and renew themselves over a long time.
The synthetic embryos created in the laboratory have cells which eventually form the placenta, yolk sac and the embryo itself. However, they are devoid of a beating heart or the beginnings of a brain. Professor Magdalena Żernicka-Goetz from the University of Cambridge and California Institute of Technology described the research on Wednesday at the annual meeting of the International Society for Stem Cell Research in Boston.
According to Żernicka-Goetz, human embryo-like models can be created by the reprogramming of embryonic stem cells. However, there is no near-term possibility of the synthetic embryos being used clinically, and it would be illegal to implant them into a patient's womb. It is not yet clear whether the structures will be able to mature beyond the earliest stages of development.
The motivation behind this research is to understand the "black box" period of development which occurs about 16 or 17 days after fertilisation, and more than a week after the free-floating embryo has anchored itself to the lining of the womb. Since scientists are only allowed to cultivate embryos in the laboratory up to a legal limit of 14 days, the researchers decided to conduct this study to observe what happens during the black box period.
The model structures have reached the beginning of a developmental milestone called gastrulation, an early developmental process in which an embryo transforms from a one-dimensional layer of epithelial cells, the blastula, and reorganises into a multi-layered and multidimensional structure called the gastrula. A mammalian gastrula is a three-tissue-layered organism that consists of the ectoderm, mesoderm and endoderm. The gastrula sets up the basic axes of the body.
Primordial cells called amnion and germ cells, which are the precursor cells of egg and sperm, are present in the model. However, a beating heart, intestinal tract of the beginnings of the brain are not present in a gastrula. It is not known whether the structures could theoretically grow into a living creature. For instance, while the synthetic embryos created from mouse cells appeared almost identical to natural embryos, they did not develop into live animals when implanted into the wombs of female mice.
This research is a milestone in the advancement of stem cell research and has opened up a world of possibilities. It has the potential to provide scientists with a better understanding of human development, and to help in the diagnosis and treatment of genetic disorders. However, it also raises ethical and legal issues that need to be addressed.
