The world’s first ever monkey-pig hybrids have been created by Chinese scientists. A team from the State Key Laboratory of Stem Cell and Reproductive Biology in Beijing was able to produced creatures with hearts, livers, spleens, lungs and skin which contained both pig and primate cells. The research paper on the experiments have been published in Protein and Cell.
The groundbreaking experiment grew stem cells from macaque monkeys in a lab that produced a fluorescent protein, allowing the researchers to track the cells and descendant cells. These modified cells were injected into the pig embryos five days after fertilization. Of more than 4,000 implanted in sows using IVF, ten piglets were born. Two of the piglets were found to have DNA from macaque monkeys in their heart, liver, spleen, lungs, and skin.
According to the scientists, the monkey cells made up only one in 1,000 and one in 10,000 of the remaining pig cells. The scientists now want to repeat the experiments to create healthy animals with higher concentrations of monkey DNA. The eventual goal is to create animal with an organ containing only monkey DNA.
The two chimera piglets died within a week of being born at the laboratory. The scientists said it was unclear why they died, but eight other normal piglets died as well. The researchers believe that this indicates there was a problem with the IVF process rather than chimerism.
The experiments that created the monkey-pig hybrids was part of research into the growth of human organs for transplantation in animals. It is hoped the research could offer an alternative to organ donation. It is estimated that 12 people a day die in the U.S. because replacement organs cannot be found in time.
The researchers wrote that the results brought the team “one step closer to producing tissue-specific functional cells and organs in a large animal model.” This was not the first time hybrid animals have been created in a lab. A team at Stanford University in California created mice with a rat pancreas in 2010. In 2017, researchers at the Salk Institute in California created pig-human chimeras. In July, Chinese scientists proposed creating monkeys with partially human-derived brains in order to better study diseases like Alzheimer’s.