2. Hello
Welcome everyone!!!
I am Dolly the Sheep
• I am here due to advances in animal biotechnology
• I was the first cloned mammal
• I was born on 5th July 1996
• I was euthanised on 14th February 2003 due to
progressive lung disease and severe arthritis
3.
4. Cloning
• A clone is a genetically similar organism or cell to another cell or organism
• In animal cloning, a single cell is taken from an animal (parent) and is used to
produce a genetically identical organism
• Cloning can also happen naturally—twin development from a single zygote
and asexual reproduction in certain animals
• Due to advancements in biotechnology, it is also possible to replicate the
process of animal cloning as it happens in nature
6. • The name Dolly was given after Dolly Parton, an American country singer,
actress, businesswoman and philanthropist
• It was born in the laboratory of Roslin Institute (Edinburgh University), Easter
Bush, Midlothian, Scotland
• It was created by Somatic Cell Nuclear Transfer (SCNT) from a fully
differentiated non-germ cell of an ewe born on February 1996.
• Here, the nucleus of a differentiated somatic cell with the organism’s DNA is
first taken away (donor). This nucleus is then inserted into an enucleated ovum
(recipient) of another parent
OR
The entire donor cell may be fused with the enucleated ovum
7. Procedure
• From a Finn-Dorset ewe, udder cells were taken
• These udder cells were cultured in a medium lacking important nutrients and as
a result, the cells stopped growing and dividing, i.e., got arrested in G0 phase of
the cell cycle
• An unfertilised ovum from a black-faced ewe was enucleated
• Both were fused by a tiny pulse of electricity. This kickstarts the cell division
activity
• This cleaved like a normal zygote, which was transplanted into the uterus of a
third adult black-faced ewe (surrogate mother), who gave birth to Dolly after 148
days
8.
9. • Dolly was a healthy, normal Finn-Dorset white ewe born to a black-faced ewe
• To prove the ewe was not secretly mated with someone else, a DNA
fingerprint of Dolly was taken. It exactly matched with that of the cells from the
tissue culture of the Finn-Dorset udder cells and not with that of the black-
faced ewe
• Although a great method, the success rate is too low. Out of 277 nuclei
transferred, only 29 grew to embryo. Even out of these, only 13 successfully
got transplanted to surrogate mother. Among them, only 1 grew into Dolly
10. Importance
• Dolly shattered the myth that adult cells are too specialised to generate a new
organism
• Scientists used to believe only pluripotent cells could give rise to a new
organism, but Dolly successfully proved otherwise as it was derived from a
fully differentiated cell
