Dogged by doubts

[摘要] Snuppy the Afghan hound was supposedly the first dog to be cloned by somatic-cell nuclear transfer. However, in the wake of controversy over the genetic cloning techniques used by his creator Woo Suk Hwang, Snuppy's credentials are being called into question. Robert Lanza, Hwangs leading competitor, claims that the technique used by Hwang may not be somatic-cell nuclear transfer, but instead a technique known as embryo splitting. This can only be proved by examining the dogs mitochondrial DNA.