Growing human organs inside pigs in Japan

Meiji University professor Hiroshi Nagashima is creating chimeric pigs, which carry genetic material from two different species, BBC News reports. It starts off by making what Nagashima calls “a-pancreatic” embryos. Inside the white pig embryo, the gene that carries the instructions for developing the animal’s pancreas has been “switched off.”

The Japanese team then introduces stem cells from a black pig into the embryo. What they have discovered is that as the pig develops, it will be normal except for its pancreas, which will be genetically a black pig’s.