Researchers at the University of Cambridge combined three types of mouse stem cells, one that normally builds the embryo itself and two that normally build supporting tissue like the placenta, and let them self-assemble without any egg or sperm involved.
The resulting structures organized themselves into a shape closely resembling a natural mouse embryo and kept developing for 8.5 days, reaching the stage where a real embryo has a beating heart-like structure, a neural tube, somites, and the beginnings of a gut, matching a Weizmann Institute model reported weeks earlier.
The model let researchers watch organ formation happen in a dish rather than inside a uterus, at a stage of development normally impossible to observe directly in a living mammal. It was not implanted and could not have developed into a live mouse, and the same groups have since pushed similar human stem-cell models further, raising separate ethical and regulatory questions of their own.
Read the original study
Amadei et al., Nature, 2022 · doi.org/10.1038/s41586-022-05246-3
A heartbeat, with no mother involved.
Source
- Amadei, G., Handford, C. E., Qiu, C., De Jonghe, J., Greenfeld, H., Tran, M., Martin, B. K., Chen, D.-Y., Aguilera-Castrejon, A., Hanna, J. H., Elowitz, M. B., Hollfelder, F., Shendure, J., Glover, D. M., & Zernicka-Goetz, M. (2022). Embryo model completes gastrulation to neurulation and organogenesis. Nature, 610(7930), 143–153. https://doi.org/10.1038/s41586-022-05246-3