Scientists ‘open Pandora’s box’ with human-monkey chimeric embryo

Some experts fear the discovery is marred by significant moral and ethical dilemmas, Sam Hancock writes

An image from the Salk Institute shows human cells grown in an early stage monkey embryo (Salk Institute)

Scientists in the US have sparked an ethics row after successfully growing part-human, part-monkey chimeric embryos.

Chimeras are organisms whose cells come from two or more individuals. Interspecies chimeras in mammals have been made since the 1970s, when they were generated in rodents and used to study early developmental processes.

Taking the research a step further, a team at the Salk Institute in California have now produced monkey-human chimeras – by injecting human stem cells into macaque embryos – in petri dishes.