Reveal the fate of 4 Dolly sheep cloned

Dolly had many problems and died young, but the fate of a clone was exactly the same as Debbie, Denise, Dianna, Daisy was different.

On July 5, 1996, Dolly was the first mammal to be cloned in the world. Dolly is hailed as the great achievement of science. However, this is also an example of a warning nature.

Genetic tests show Dolly's DNA has signs of aging when it is one year old. At age 5, he was diagnosed with arthritis. It is still unclear whether Dolly's problems are because it is cloned. In 2003, Dolly died when she was 6 years old - half the typical life of sheep of the same type.

Debbie, Denise, Dianna, Daisy are collectively referred to as "Dolly" because they are exact copies of Dolly's sheep gene.

Dolly's tissue samples are stored and used to create new clones of sheep. Four sheep Debbie, Denise, Dianna, Daisy were called "Dolly" because they were identical, the exact copies of Dolly's sheep died. These four "Dolly of Nottingham" are survivors from a group of 10 Dolly clones born in 2007.

Since then, researchers at the University of Nottingham have looked after them closely. At a news conference in the UK earlier this week, researcher David Gardner said: "We want to evaluate these animals physiologically to see if they are normal." They raised Dolly and nine other normal sheep to measure their metabolic, cardiovascular and musculoskeletal health.

After many years, the scientific group announced four cloned individuals (4 years old) derived from Dolly's healthy and alive cell line. Although Dolly suffered from early osteoarthritis, only one of its four copies, the sheep named Debbie, showed mild arthritis.

Veterinarians and research collaborators, Sandra Corr, told the press: "Metabolism and cardiovascular health are good, they cannot distinguish them and other sheep of the same age. We find that most The sheep is really healthy in terms of their age. "

Copies of Dolly were created using the same method of creating Dolly - somatic cell nuclear transfer technology - (Photo: Guardian).

These sheep are cloned using the same method of creating Dolly, somatic cell nuclear transfer technology. In it, scientists removed the DNA (in the nucleus of the cell) from a cell of the original animal (in this case, from the mammary gland of the original sheep), then transferred it into the nucleus of Oocytes. They stimulated the cell to divide by electric shock until it developed into the embryo. Then they implanted embryos into the womb of a third sheep. The creation of Dolly has shown that a cell is taken from special body parts that can reproduce a complete body.

According to lead researcher, Kevin Sinclair, this is the most in-depth study of health cloned copies according to the lifespan calculated to date. The good health of Dolly is a sign that clones can live long and live healthy.