It's been 20 years since the birth of Dolly the Sheep took the world by storm. Researchers led by the University of Edinburgh's Ian Wilmut cloned the sheep using DNA from an adult sheep's mammary gland and named it after country singer Dolly Parton, as they recount at Scientific American.
Many of the feared outcomes of cloning haven't come to pass, a separate Scientific American piece notes — humans haven't been cloned, no designer babies abound — but cloning has still had an effect.
One of cloning's legacies, according to Sciam, is its influence on the stem cell field. "Dolly the Sheep told me that nuclear reprogramming is possible even in mammalian cells and encouraged me to start my own project," Shinya Yamanaka, who won the 2012 Nobel Prize for his work on induced pluripotent stem cells, wrote in an email to the magazine. Meanwhile, other stem cell researchers use cloning techniques to produce embryonic stem cells, rather than collecting new samples.
In addition, the somatic cell nuclear transfer technique used is now being combined with in vitro fertilization to enable women with mitochondrial defects to use donor eggs with healthy mitochondria, but her own nucleus to have children who are at lower risk of developing that mitochondrial condition, notes Columbia University's John Loike in another Scientific American piece.
But these three-person embryos are bringing up similar ethical issues as did Dolly, he notes. He predicts, though, once a healthy baby, free of mitochondrial disease, is pictured on Facebook, then "the world will accept this technology, despite ethical concerns."