Monkey embryos were genetically modified to create a hybrid embryo. They deactivated certain genes that lead to the formation organs, and then injected the embryo with human stem cells.
This breakthrough experiment, which is considered an important step forward towards using animals for human organ transplants, had to take place in China to avoid legal issues.
The findings have not yet been published, but the team reported the creation of the hybrid to El País.
The embryo was destroyed at 14 days of gestation, which is dubbed the ‘red line’, meaning the embryo did not yet develop a central nervous system.
The scientist Juan Carlos Izpisúa Belmonte also hit the headlines in 2017 as he was responsible for creating the first human pig hybrid.
The 2017 experiment was less successful but his team could claim that they conducted ‘the first experiment of human and pig chimeras in the world’.
A genetic chimera, or chimerism, is a single organism composed of cells from different individuals.
University of California veterinarian Pablo Ross, Professor Izpisua’s colleague, said:
“The human cells did not take hold. We saw that they contributed very little [to the development of the embryo]: one human cell for ever 100,000 pig cells”
The team were able to more easily create chimeras between species more similar to eachother, such as the rat and the mouse, when are 5 times closer than pigs and humans.
Project collaborator Estrella Núñez described this experiment as ‘very promising’. He said:
‘We are now trying not only to move forward and continue experimenting with human cells and rodent and pig cells, but also with non-human primates. Our country is a pioneer and a world leader in these investigations’
The team will continue to experiment with human, pig, and rodent cells, as well as with non-human primates.
Source: The Independent