Researchers have coaxed cloned rhesus macaque embryos to grow to the blastocyst stage, a developmental benchmark in which cells form a hollow, fluid-filled ball. The accomplishment marks the furthest point that scientists have yet reached in cloning a nonhuman primate.
Scientists have long been interested in human cloning as a therapeutic tool. Unlike reproductive cloning, which is meant to create genetically identical organisms, therapeutic cloning aims to grow embryonic stem cells into tissue that matches a patient's genetic signature.
Scientists have proposed stem cells as a means to treatments for a wide range of diseases, including Parkinson's and diabetes.