(Nature) – The hearts started to beat in the pig–human hybrids, which survived for 21 days.

Researchers have reported growing hearts containing human cells in pig embryos for the first time. The embryos survived for 21 days, and in that time their tiny hearts started beating. The findings were presented this week at the annual meeting of the International Society for Stem Cell Research in Hong Kong.

Scientists developing human–animal chimaeras grow human cells in animal embryos, with the aim of one day generating animals with human organs that can be transplanted into people. This could provide a way to address the global shortage of organs for transplantation. (Read More)