Birds, especially chickens, are very useful in scientific research. They help scientists study how animals grow, fight diseases, and pass on traits. Chickens have even helped us learn more about human illnesses.
But there’s a problem: scientists don’t have many genetic tools for birds, which makes research harder. While special stem cells (called germline-competent embryonic stem cells) have been created from mice and rats, they haven’t been made from other animals yet. If scientists can overcome this challenge, it could open up new possibilities for studying many types of birds, including rare species, birds that are hard to study, and those important for farming.
Caltech scientists have created a new method to freeze and store bird stem cells, helping preserve and grow bird populations.
With this technique, stem cells are taken from very early embryos and grown in the lab for several months. These cells, capable of turning into different types of body cells, are then frozen and saved. Later, they can be thawed, grown again, and placed into an egg, which is incubated to develop into a bird.
Because working with endangered birds is risky, researchers tested their new stem cell method on more common species like quail, pheasant, turkey, goose, chicken, peafowl, duck, and ostrich.
They collected embryos from freshly laid fertile eggs at a specific early stage (EGK.X–XII), keeping the eggs at 16°C before using a filter paper technique to harvest the embryos.
In chickens, the embryonic stem (ES) cells showed strong potential, they carried key markers that allow them to turn into any type of cell in the body, including those outside the embryo. When these cells were injected into chicken embryos, they successfully formed mixed individuals (chimeras) and produced germ cells both in lab dishes and inside the eggs.
Researchers also found that the way stem cells renew themselves is similar across different bird species. This means that stem cells from many types of birds can be grown using lab methods originally designed for chickens.
By successfully creating true avian stem cells, scientists now have a powerful tool that could help with genetic research and protecting bird biodiversity, especially for rare or endangered species.
Carlos Lois, research professor of biology said, “Currently, protecting remaining individuals is our only strategy to prevent bird extinction. However, despite intensive conservation efforts, many species continue to vanish. The techniques we’re developing will enable reconstituting birds from stored cells of endangered species, even after extinction, creating a permanent repository for species restoration.”
Journal Reference:
- Chen, X., Guo, Z., Tong, X. et al. Derivation of embryonic stem cells across avian species. Nat Biotechnol (2025). DOI: 10.1038/s41587-025-02833-3
