Scientists for the First Time Produced Mixed Embryo Monkeys

Scientists for the first time produced monkeys composed of cells taken from separate embryos.   They combined cells from different embryos and implanted them into female monkeys. The cells never fuse, but they stay together and work together to form tissues and organs. The animals, which contain genetically distinct groups of cells from more than one organism, are termed as chimeras. The three rhesus monkeys born are named Chimero, Roku and Hex. These monkeys have tissues made up of a mixture of cells, which represent as many as six separate embryos.

Although Chimeras are essential for studying embryonic development, research has largely been restricted to mice. Initial efforts by the scientists to produce living monkey chimeras by introducing cultured embryonic stem cells into monkey embryos failed.