The Legacy of Dolly the Sheep May Be Your Future Health

The first mammal cloned from an adult cell, Dolly the sheep. In 1997, The Roslin Institute introduced Dolly to the world. It caused a frenzy of attention. In the twenty-five years since Dolly’s birth, we have cloned many more species of animals with little fanfare. In February 2021, scientists announced they’d successfully cloned the first U.S. endangered species, the black-footed ferret. The ferret is just one part of Dolly’s legacy. The other part of the legacy of Dolly the sheep may be your future health. The Life of Dolly the Cloned Sheep Born on July 5th 1996, Dolly’s white face confirmed she was a clone. The black-faced surrogate ewe who birthed her could not be her genetic mother. Scientists tested Dolly’s DNA when she was one. They discovered that her DNA telomeres (end caps) were shorter than expected. Scientists thought that since the cells used to create Dolly came from an adult sheep may have caused the abnormality. They thought the adult cells somehow prevented her telomeres from developing normally. At two, Dolly mated with a Welsh Mountain ram called David. Dolly gave birth to a female lamb in 1998,. She had twin lambs the next year and triplets in […]

When is a Clone Not a Clone

Bees do it. Lizards and snakes do it. Turkeys and Komodo Dragons can do it. Have babies without daddies, that is. It’s called Parthenogenesis. And it’s sort of when a clone isn’t a clone. Parthenogenesis a form of asexual reproduction in which growth of the embryo occurs without fertilization. The growth of the embryo begins due to a change in temperature, a mechanical action, or a chemical action. The term applies only to animals. (Botanical asexual reproduction is called something else.) And since the offspring are clones of the mother, they are usually female. This phenomenon was first observed in aphids and recorded by Charles Bonnet in the 18th century. In 1899, Jacques Loeb reported artificial parthenogenesis in sea urchins. Gregory Pincus used temperature and chemicals to induce embryonic development in rabbit eggs in 1936. Today, some sources say about 70 vertebrates can reproduce this way and if you include all organisms that number will top 2000 species. Some species are obligatory parthenogenic, in other words, they cannot reproduce sexually at all. Other species are facultatively parthenogenic, meaning they have the ability to switch between sexual and parthenogenic reproduction. There have been no known natural parthenogenic offspring in mammals. There […]