20 Years After Dolly, Where Is Cloning Heading?
WHY YOU SHOULD CARE
Because you’re still not seeing double.
Dr. Bertalan Mesko is the Medical Futurist, a health care speaker and author of The Guide to the Future of Medicine and My Health: Upgraded.
The world was stunned when scientists revealed back in February 1997 that they had successfully cloned a tiny white animal several months earlier. Dolly the sheep — named after country music legend Dolly Parton — was nothing short of an international sensation. Few had dreamed before her arrival that science could produce a cloned mammal. But the success saw science fiction writers delve into the future of cloned societies, and governments drafted legislation to ward off ethically questionable developments. But what has happened since — and are we on the cusp of resuscitating a long-extinct species, Jurassic Park style?
When Dolly developed lung disease and had to be put down at age 6 — around 40 in human years — cloning fever cooled, along with dreams of human replicas. Fears surfaced that clones could not live as long as their originals due to underlying genetic abnormalities. Seventy countries subsequently banned human cloning, citing medical and ethical challenges, not to mention dystopian fears. There also proved to be zero commercial interest in human clones.
Even if it were possible to clone deceased loved ones, why would we?
So will it ever be possible for the uber-rich to clone themselves for spare body parts, like on The Island? Or for parents who lost children in tragic accidents to have replacements? Four years ago, Nobel Prize-winning British developmental biologist Sir John Gurdon said it was conceivable, but I’m not convinced. In the very distant future, where we have solved the ethical challenges (or completely ignored them), even if it were possible to clone deceased loved ones, why would we? After all, it would take the same years for the clones to grow up as for regular human beings. Getting a clone right away who’s the same age as you exists only in science fiction.
Either way, one thing is clear: Dolly’s legacy lives on. Last year, scientists proved that the early concerns about clones’ premature aging were wrong. Researchers reported that 13 cloned sheep, including four genomic copies of Dolly, are still in good shape at between 7 and 9 years old, the equivalent of 60 to 70 in human years. And while the first hype around Dolly led to fears about human reproductive cloning, the mainstream scientific community is currently focused more on cloning for therapeutic purposes.
There is a huge difference between the two. Reproductive cloning involves creating a genetically identical being, like Dolly or, hypothetically, a deceased relative, through somatic cell nuclear transfer. But in the case of therapeutic cloning, doctors would take a cell from a patient, put its nucleus into an enucleated egg and get the cell to begin dividing and multiplying in a lab dish, eventually producing specialized cells like neurons and pancreatic beta cells. This would enable researchers to study how these cells behave. But creating human cells through this method is incredibly difficult.
Three years ago, Dieter Egli and his research group at the New York Stem Cell Foundation used a variation on the Dolly recipe to create the first disease-specific cell lines from a patient suffering from Type 1 diabetes. The donor’s DNA plus a DNA-free egg produced a line of cells Egli is using to grow insulin-producing beta cells that match the donor precisely, minimizing chances of rejection. And this is where Dolly deserves the most credit: Thanks to her, scientists have been able to start focusing on reprogramming adult cells and trying to turn them into functioning cells, like diabetes-curing beta cells. They’re not quite there yet, but promising progress is being made.
I believe this is one of the most probable future medical uses of cloning. People with heart disease, Alzheimer’s and diabetes can soon expect a medical breakthrough involving cloned stem cells, from which new and healthy tissues could be grown. Nevertheless, cloning will also be used as a molecular biology method more and more in biotechnology and for developing new pharmaceuticals. As an example, it is possible to grow cells from a cow that produces large amounts of milk and insert a gene into the DNA of these cells that codes for a drug or even a vaccine. Transferring the nucleus from one of these cells to a cow egg could result in a cow that produces the drug in its milk.
Also, hope remains when it comes to animal cloning. Dolly not only had a significant impact on medicine, but she provided hope for endangered species, too. In 2001, scientists cloned a gaur, aka Indian bison, and in 2003, a clone species of wild ox was born. Although both died within days, efforts for successfully cloning threatened species, like giant pandas, are still under way.
While I do not believe that long-extinct species will see revivals, or that clones will (or should) walk among us, I do believe that cloning — much like the revolutionary gene-editing method called CRISPR — has the potential to positively affect the future of humanity.