Described Cloning.

1. Cloning
Bio-informatics

2. Introduction
 Cloning: Creating copies of living matter
 The term clone (from the Greek word klōn,
meaning “twig”) had already been in use
 since the beginning of the 20th century
 in reference to plants
 Clones have identical genetic makeup
 Abundant in nature
 Used by scientists to generate organisms with
valuable traits

3. Initial Efforts
 1800’s- First try of using
undifferentiated cells
 Hans Dreisch separated a sea urchin
embryo when it was just two cells
 Both cells grew to adults
 Early 1900’s- Hans Spemann extended
Dreisch’s work to salamanders
 Determined that nucleus from embryo
cell could direct the development of a
complete organism
 Published his results in 1938
 Proposed a “fantastical” experiment

4. Early Frog Experiments
 1952- Spemann’s idea
realized by Robert Briggs
and Thomas King
 Used cell nuclear transfer to
insert DNA from a frog embryo
cell into an enucleated frog egg
 Resulting embryo grew into an
adult
 Early experiments using cell
nuclear transfer were successful
only when donor DNA was
taken from an embryonic cell

5. Early Frog Experiments
(Gurdon’s Method)
 1962- John Gurdon began cloning experiments
using non-embryonic cells
 Cells from intestinal lining of tadpoles
 Exposed a frog egg to ultraviolet light, which
destroyed its nucleus
 Removed the nucleus from the tadpole
intestinal cell and implanted it in the enucleated
egg
 Egg grew into a tadpole that was genetically
identical to the DNA-donating tadpole

6. Impact of Gurdon’s Research
 Gurdon’s experiments captured the attention of
the scientific community
 Tools and techniques he developed for nuclear
transfer are still used today
 1963- J. B. S. Haldane, in describing Gurdon’s
results, became one of the first to use the word
clone in reference to animals

7. What Does It Mean: “To
Clone”?
A Collection Of Molecules Or Cells, All Identical To An
Original Molecule Or Cell.

8. “To "clone a gene" is to make many copies of it - for
example, by replicating it in a culture of bacteria.
• Cloned gene can be a normal copy of a gene (= “wild
type”).
• Cloned gene can be an altered version of a gene (=
“mutant”).
• Recombinant DNA technology makes manipulating
genes possible.
• To work directly with specific genes, scientists prepare
gene-sized pieces of DNA in identical copies, a process
called DNA cloning

9. DNA cloning
Most methods for cloning
pieces of DNA in the
laboratory share
general features, such as
the use of bacteria and
their plasmids
Plasmid:
• Are Small Circular DNA
Molecules That Replicate
Separately From The
• Bacterial Chromosome
Gene cloning involves
using bacteria to make
multiple copies of a
gene

10. Gene cloning, genetic engineering,
recombinant DNA technology
▣ Joining Together DNA
From
Different
Sources/Organisms,
Forming A Recombinant
DNA
Molecule
▣ Then put this recombinant
DNA into a host cell,
usually bacteria
▣ The host cell will then
replicate many copies
of this recombinant
DNA molecule
▣ Sometimes, we might
want to ask the host
cell to use the genetic
information in the
recombinant DNA to
make proteins

11. Why clone sheep?
1. Dolly the sheep was produced at the Roslin Institute as part of research
into producing medicines in the milk of farm animals.
2. Researchers have managed to transfer human genes that produce
useful proteins into sheep and cows, so that they can produce,
3. Inserting these genes into animals is a difficult and laborious process;
cloning allows researchers to only do this once and clone the resulting
transgenic animal to build up a breeding stock.
4. The development of cloning technology has led to new ways to
produce medicines and is improving our understanding of development
and genetics.

12. Since Dolly
 1.Since 1996, when Dolly was born,
other sheep have been cloned
from adult cells, as have cats,
rabbits, horses and donkeys, pigs,
goats and cattle. In 2004 a mouse
was cloned using a nucleus from
an olfactory neuron.
 2. Improvements in the technique
have meant that the cloning of
animals is becoming cheaper and
more reliable.

13. Since Dolly
 3. Cloning animals have led to
a potential new therapy to
prevent mitochondrial diseases
in humans being passed from
mother to child.
 4. To prevent this, genetic
material from the embryo is
extracted and placed in an
egg cell donated by another
woman, which contains
functioning mitochondria.
▣5. This is the same process as used in
cloning of embryonic cells of animals.
Without this intervention, the faulty
mitochondria are certain to pass on to
the next generation.
▣6. Moreover, the treatment is currently
not permitted for use in humans.
However, the Human Fertilization &
Embryology Authority in the UK has
reported that there is general support
in the public for legalizing the therapy
and making it available to patients.

14. “Cloning Dolly the sheep
Dolly the sheep, as the first
mammal to be cloned from
an adult cell, is by far the
world's most famous clone. A
clone has the same DNA
sequence as its parent and
so they are genetically
identical.

15. How Dolly was cloned
▣To produce Dolly, scientists used an udder cell from a six-year-old Finn Dorset white
sheep. They had to find a way to 'reprogram' the udder cells - to keep them alive
but stop them growing – which they achieved by altering the growth medium.
▣ Then they injected the cell into an unfertilized egg cell which had had its nucleus
removed, and made the cells fuse by using electrical pulses. The unfertilized egg cell
came from a Scottish Blackface ewe.
▣When the research team had managed to fuse the nucleus from the adult white
sheep cell with the egg cell from the black-faced sheep, they needed to make sure
that the resulting cell would develop into an embryo.
▣ They cultured it for six or seven days to see if it divided and developed normally,
before implanting it into a surrogate mother, another Scottish Blackface ewe. Dolly
had a white face. And finally Dolly was born after 148 days.

16. “
What happened to Dolly?

17. What happened to Dolly?
▣
• Dolly suffered from arthritis
in a hind leg joint and from
sheep pulmonary
adenomatosis, a virus-
induced lung tumour that
is common among sheep
which are raised indoors.
• Dolly’s chromosomes were
a little shorter than those of
other sheep her age and
her early ageing may
reflect that she was raised
from the nucleus of a 6-
year old sheep. Dolly was
also not entirely identical
to her genetic mother
because the
mitochondria.

18. Thanks!
Any questions?
You can find me at ador.fazlerabbi@gmail.com