Dolly (sheep)

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Dolly

Dolly with her firstborn lamb, Bonnie

Other

name

6LLS (code name)

(

)

Sex

Female

Born

5 July 1996

Died

14 February 2003

(aged 6)

Roslin Institute, Midlothian,

Scotland

Cause of

death

Resting

place

(remains on display)

Known for

First

from an

adult

Offspring

6 lambs (Bonnie; twins Sally

and Rosie; triplets Lucy, Darcy

and Cotton)

Named

after

Dolly

(5 July 1996 – 14 February 2003) was a female

sheep and the

first

that was

from an adult

. She was cloned by

associates of the

in Scotland, using the process of

from a cell taken from a

(

Her cloning

proved that a cloned organism could be produced from

a mature cell from a specific body part.

Contrary to popular belief, she

was not the first animal to be cloned.

The employment of adult somatic cells instead of

for

cloning emerged from the foundational work of

, who cloned

in 1958 with this approach. The successful cloning of Dolly led

to widespread advancements within stem cell research, including the discovery

Dolly lived at the Roslin Institute throughout her life and produced several

lambs.

She was euthanized at the age of six years due to a progressive lung

disease. No cause that linked the disease to her cloning was found.

Dolly's body was preserved and donated by the Roslin Institute in Scotland to

the

, where it has been regularly exhibited since

2003.

Genesis

Dolly was

, and colleagues at the

, part of the

, Scotland, and the

biotechnology company PPL Therapeutics, based near

. The funding for

Dolly's cloning was provided by PPL Therapeutics and the

She was born on 5 July 1996.

She has been called "the

world's most famous sheep" by sources including

and

The cell used as the donor for the cloning of Dolly was taken from a

, and the production of a healthy clone, therefore, proved that a cell

taken from a specific part of the body could recreate a whole individual. On

Dolly's name, Wilmut stated, "Dolly is derived from a mammary gland cell and

we couldn't think of a more impressive pair of glands than

's."

Birth

Dolly was born on 5 July 1996 and had three mothers: one provided the egg, another the DNA, and a third carried the

cloned embryo to term.

She was created using the technique of

, where the

from an adult cell is transferred into an unfertilized

(developing egg cell) that has had its cell

nucleus removed. The hybrid cell is then stimulated to divide by an electric shock, and when it develops into a

it is implanted in a surrogate mother.

Dolly was the first clone produced from a cell taken from an

adult mammal.

The production of Dolly showed that genes in the nucleus of such a mature

somatic

cell are still capable of reverting to an embryonic

state, creating a cell that can then go on to develop

into any part of an animal.

Dolly's existence was announced to the public on 22 February 1997.

It gained much attention in the media. A

commercial with Scottish scientists playing with sheep was aired on TV, and a special report in

Time

magazine featured

Dolly.

featured Dolly as the

. Even though Dolly was not the first animal cloned,

she received media attention because she was the first cloned from an adult cell.

Life

The

process that

produced Dolly

Dolly lived her entire life at the

in Midlothian.

There she was

bred with a

and produced six lambs in total. Her first lamb,

named Bonnie, was born in April 1998.

The following year, Dolly produced twin

lambs, Sally and Rosie; further, she gave birth to triplets Lucy, Darcy, and Cotton

in 2000.

In late 2001, at the age of four, Dolly developed

and started

to have difficulty walking. This was treated with

drugs.

Death

On 14 February 2003, Dolly was

because she had a progressive lung disease and severe arthritis.

such as Dolly has a life expectancy of around 11 to 12 years, but Dolly lived 6.5 years. A post-mortem

examination showed she had a form of lung cancer called

, also known as Jaagsiekte,

which is a fairly common disease of sheep and is caused by the

Roslin scientists stated that they

did not think there was a connection with Dolly being a clone, and that other sheep in the same flock had died of the

same disease.

Such lung diseases are a particular danger for sheep kept indoors, and Dolly had to sleep inside for

security reasons.

Some in the press speculated that a contributing factor to Dolly's death was that she could have been born with a

genetic age of six years, the same age as the sheep from which she was cloned.

One basis for this idea was the

finding that Dolly's

were short, which is typically a result of the

process.

The Roslin

Institute stated that intensive health screening did not reveal any abnormalities in Dolly that could have come from

advanced aging.

In 2016, scientists reported no defects in thirteen cloned sheep, including four from the same cell line as Dolly. The

first study to review the long-term health outcomes of cloning, the authors found no evidence of late-onset, non-

communicable diseases other than some minor examples of osteoarthritis and concluded "We could find no evidence,

therefore, of a detrimental long-term effect of cloning by SCNT on the health of aged offspring among our

cohort."

After her death Dolly's body was preserved via taxidermy and is currently on display at the

in Edinburgh.

Legacy

The

mount of Dolly on

exhibit at the

in 2009

After cloning was successfully demonstrated through the production of Dolly, many

other large mammals were cloned, including pigs,

horses

and

bulls.

The attempt to clone

(mountain sheep) did not produce viable

embryos. The attempt to clone a

bull was more successful, as were the

attempts to clone

(a form of wild sheep), both resulting in viable

offspring.

The reprogramming process that cells need to go through during cloning is not perfect and embryos

produced by nuclear transfer often show abnormal development.

Making cloned mammals was highly inefficient

back then – in 1996, Dolly was the only lamb that survived to adulthood from 277 attempts. Wilmut, who led the team

that created Dolly, announced in 2007 that the nuclear transfer technique may never be sufficiently efficient for use

in humans.

But by 2014, Chinese scientists were reported to have 70–80% success rates cloning pigs,

and in

2016,

was producing 500 cloned embryos a day.

Another Korean

company,

the firm charges $50,000 (£38,000) to clone a dog, $30,000 for a cat, and $85,000 for a horse, showing cloning economy

is getting more popular despite the cost.

Cloning may have uses in preserving endangered species, and may become a viable tool for reviving

In January 2009, scientists from the Centre of Food Technology and Research of Aragon in northern Spain announced the

cloning of the

, a form of wild mountain goat, which was officially declared extinct in 2000. Although

the newborn ibex died shortly after birth due to physical defects in its lungs, it is the first time an extinct animal

has been cloned, and may open doors for saving endangered and newly extinct species by resurrecting them from frozen

tissue.

In July 2016, four identical clones of Dolly (Daisy, Debbie, Dianna, and Denise) were alive and healthy at nine years

old.

The

Dollies, were humanely euthanised following research published in 2017, natural life

expectancy of sheep rarely extends beyond nine to 10 years, after re-examine Dolly's case, showing they were all aging

normally.

[

]

concluded in 2016 that the main legacy of Dolly has not been cloning of animals but in advances

into

research.

Gene targeting was added in 2000, when researchers cloned female lamb Diana from sheep

DNA altered to contain the human gene for

The human gene was specifically activated in the ewe’s

mammary gland, so Diana produced milk containing human

After Dolly, researchers realised that

ordinary cells could be reprogrammed to

, which can be grown into any tissue.

The first successful cloning of a

was reported in January 2018, using the same method which produced

Dolly. Two identical clones of a

monkey,

, were created by researchers in China and

were born in late 2017.

In January 2019, scientists in China reported the creation of five identical cloned

monkeys, again using

this method, and the gene-editing

technique allegedly used by

in creating the first ever gene-

modified human babies

. The monkey clones were made in order to study several medical diseases.

In popular culture

In 2003, Belgian artist

published a short comic strip about Dolly the cloned sheep with the title:

“2004 Apparition de Dolly dans la campagne anglaise”