The developing embryo is a human embryo inside a cow egg. We don't know what kind of creature could develop from that. There is no precedent in history. Robl says the human genes would take over and only a little bit of mitochondrial DNA from the cow would remain. Last January, Neal First and colleagues at the University of Wisconsin said he had cloned animals of several species using hollowed-out cow eggs, although none were successfully implanted into an animal and grown.
Many animals already exist that carry human genes.
Cows have been made that produce human proteins in their milk, as have sheep, pigs, rabbits and mice. All sorts of mice used in research carry human genes. But Andrews says Advanced Cell's creation is different. But by using the entire genetic makeup for a human being, what you have done is to create a potential human embryo. In many states this is already against the law.