Two research groups at Newcastle University and King's College London have today been granted the first licences to work on human-animal embryo hybrids.
After a consultation, the Human Fertility and Embryology Authority said that research can go ahead because the proposals satisfy all legal requirements and public are "at ease" with the idea.
Both groups plan to insert human DNA from adult patients and lab-grown stem cells into unfertilised animal eggs.
The Newcastle team hope to use the resultant embryos to study how DNA programs different cell types during early development.
Researchers at King's College will implant DNA from patients who suffer from genetic neurodegenerative conditions, such as Parkinson's disease. They hope to create a supply of stem cells bearing the genes, so other scientists can study such diseases.
Human embryology researchers say using animal eggs is necessary to address the shortage of human eggs left over from IVF.
Hybrid embryos created by either project will not be allowed to develop beyond 14 days, when a human embryo is a loose cluster of undifferentiated cells.
Details on both licence approvals are here. ®