In an effort to alleviate the shortage of life-saving human transplant organs (of which not nearly enough are donated) scientists have embarked on a journey to grow human organs in the embryos of animals.
This is accomplished by introducing human stem cells to animal embryos during their formation.
Scientists have successfully reversed diabetes in mice in this fashion, using stem cells from the mice to grow pancreas glands in rats, then transplanting the organs back into the mice.
Now another experiment shows that all-purpose human stem cells (taken from the circumcised skin tissue of infant boys) can be genetically introduced to pigs and may be able grow human organs as well.
Biologists at the Salk Institute, led by Jun Wu and Juan Carlos Izpisua Belmonte, have succeeded in growing partially-human pigs or chimeras, which are animals that are composed of two different genomes.