A team of researchers from China has created the world’s first Pig-Monkey chimera. The scientists created the chimera by injecting monkey stem cells into the egg of a pig. The embryo was grown in vitro and later transferred to a surrogate mother. Two piglets were delivered 16 weeks later.
Chimera is a single organism that has DNA from two separate species or individuals. Here the chimeric organism is created from a pig and a monkey. In this research, they first collected the egg of a pig and was grown in the lab for 5 days for activation. They then inject embryonic stem cells (ESCs) of a monkey to the egg and were grown for another 48 hours. The embryos were then transferred to a recipient surrogate mother. Two piglets were delivered 16 weeks later. However, the two piglets survive for just 28 days due to which it was not possible to observe whether the chimera can develop into mature functional cells.
This is not the first time intergenic chimerism has been studied. In the past, there has been extensive research on chimerism using Rodents models. Japanese scientists had successfully generated an entire rat pancreas inside a mouse. The thymus of a rat has been grown in a mouse as well. However, human chimerism is more complex. The process of development is more complex as compared to rats and other lower animals. Added to that, there is a huge ethical issue in using human-animal chimera.
The ultimate goal is the generation of human-animal chimera. A human organ can be grown in another animal. Organs like the liver, pancreas or heart can be grown in a pig. This will substantially decrease the heavy demand for organ transplantation. This research will lay the foundation for the future if we are to realize the dream of growing organ in animals.
1. Domesticated cynomolgus monkey embryonic stem cells allow the generation of neonatal interspecies chimeric pigs. Protein & Cell (2019)