Creator of Dolly the Sheep Ian Wilmut Dies at 79, Leaves Behind Legacy in Regenerative Medicine

On September 10, British scientist Ian Wilmut died at the age of 79 years after being diagnosed with Parkinson's disease, as announced by the University of Edinburgh. Dubbed the "Titan of the scientific world', Wilmut generated news headlines and ethical debates in 1996 when he led the team that created Dolly, the first mammal cloned from an adult cell.

How Was Dolly Formed?

On July 5, 1996, Dolly the sheep was born at the Roslin Institute in Scotland. Originally known as "6LL3", the cloned lamb was named after singer and actress Dolly Parton.

Dolly was not the first animal to be cloned since the research on cloning technology has been conducted since the mid-20th century. However, she was the first example of a successful animal cloning from an adult mammal cell instead of a more malleable embryo.

In creating Dolly, researchers focused on arresting the cell cycle or the steps all cells must go through in dividing. In Dolly's case, the Roslin Institute team wanted to use the cells from the mammary gland of a pregnant sheep. They prevented the cells from dividing by starving them of nutrients for a week. In response, the cells fell into a slumbering phase like a deep hibernation.

At this point, embryologist Ian Wilmut and his colleagues used the cloning technique known as nuclear transfer. First, the nucleus of an unfertilized egg was removed, leaving behind the surrounding cytoplasm. Then, the egg was placed in the nucleus of a quiescent donor cell, followed by gentle pulses of electricity.

The pulses prompted the egg to accept the new nucleus and all the DNA it contained, taking them as its own. The process also triggered biochemical activity that initiated cell division. After a week, the growing embryo was implanted in the womb of a surrogate ewe.

The hint that this method might work came from Wilmut's success in producing live lambs from embryonic clones. The team also suffered from setbacks in carrying out this project. Out of 277 attempts, they only had 27 embryos, which only survived longer than six days. All these embryos died except Dolly, born 148 days after being implanted.

Dolly's Legacy in Stem Cell Research

Dolly's birth was publicly announced in February 1997, sparking debates about the benefits and dangers of cloning. After more than two decades, the impact of this breakthrough can still be seen in the cutting-edge science of our time.

Wilmut's goal for cloning is to prevent species from becoming extinct, but his work has also laid the foundation for stem cell research. It has provided new insights into developing early-stage cells from various tissues. This inspired scientists to study how their development can be controlled and how mature cells can return to behave once more as undeveloped cells.

Moreover, the success in creating Dolly has led to gene modification and gene editing advances. This technology has made beneficial changes to an organism's DNA, such as a plant or animal.

Check out more news and information on Cloning in Science Times.