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Cloning
Trekiya Brown
I. What is cloning?
Cloning is the creation of an organism that is an exact
genetic copy of another. This means that every single bit of
DNA is the same between the two!
How is cloning done?
You may have first heard of cloning when Dolly the Sheep
showed up on the scene in 1997. Cloning technologies
have been around for much longer than Dolly, though.
How does one go about making an exact genetic copy of
an organism? There are a couple of ways to do this:
artificial embryo twinning and somatic cell nuclear
transfer. How do these processes differ?
Continued…
Is cloning an organism the
same as cloning a gene?
You've heard about
cloning animals - sheep, mice,
even house pets - in the news.
From time to time, you may
have also heard about
researchers cloning, or
identifying, genes that are
responsible for various medical
conditions or traits.
What is the difference?
Cloning an animal, or any other
organism, refers to making an exact
genetic copy of that organism.
Cloning a gene means isolating an
exact copy of a single gene from
the entire genome of an organism.
Usually this involves copying the
DNA sequence of that gene into a
smaller, more accessible piece of
DNA, such as a plasmid. This
makes it easier to study the
function of the individual gene in
the laboratory.
II. Click and Clone
1.
2.
3.
4.
5.
6.
Isolate the donor cells
Remove and discard the nucleus from the egg cell.
Transfer the somatic cell nucleus into the enucleated egg
cell.
Stimulate cell division
Implant the embryo
Deliver the baby mouse clone
III. Clone Zone
Year 1996

Hello Dolly
Year 1997

Promises and Pitfalls of Human Cloning
Year 1998

To Clone or Not to Clone
Year 1999

Fibro Brings macho to Cumulina’s Arena
Year 2001

Infertility Drives Cloning Research
Year 2002

Supernatural Belief in Cloning
IV. Why Clone?
Cloning for medical purposes

Cloning animal models of disease
Much of what researchers learn about human disease comes from studying animal
models such as mice. Often, animal models are genetically engineered to carry diseasecausing mutations in their genes. Creating these transgenic animals is a time-intensive
process that requires trial-and-error and several generations of breeding. Cloning
technologies might reduce the time needed to make a transgenic animal model, and the
result would be a population of genetically identical animals for study.

Cloning stem cells for research
Stem cells are the body's building blocks, responsible for developing, maintaining and
repairing the body throughout life. As a result, they might be used to repair damaged or
diseased organs and tissues. Researchers are currently looking toward cloning as a way
to create genetically defined human stem cells for research and medical purposes.

"Pharming" for drug production
Farm animals such as cows, sheep and goats are currently being genetically engineered
to produce drugs or proteins that are useful in medicine. Just like creating animal models
of disease, cloning might be a faster way to produce large herds of genetically
engineered animals.
Continued…
Reviving Endangered or
Extinct Species
 A well-preserved source
of DNA from the extinct
dinosaur, and
 A closely related species,
currently living, that could
serve as a surrogate
mother
Reproducing a Deceased Pet

If you really wanted to, and if
you had enough money, you
could clone your beloved
family cat. At least one
biotechnology company in the
United States offers cat cloning
services for the privileged and
bereaved, and they are now
working to clone dogs. But
don't assume that your cloned
kitty will be exactly the same as
the one you know and love.
V. Clone Myth


Misconception #1: Instant Clones: Let's say you really wanted a clone
to do your homework. After reviewing What is Cloning? and Click and
Clone, you've figured out, generally, how this would be done.
Knowing what you know, do you think this approach would really help
you finish your homework...this decade
Misconception #2: Carbon Copies: Your beloved cat Frank has been a
loyal companion for years. Recently, though, Frank is showing signs of
old age, and you realize that your friend's days are numbered. You can't
bear the thought of living without her, so you contact a biotechnology
company that advertises pet cloning services. For a fee, this company
will clone Frank using DNA from a sample of her somatic cells. You're
thrilled: you'll soon have a carbon copy of Frank - we'll call her Frank
#2 - and you'll never have to live without your pal! Right?
Continued…
Explain why cc and rainbow look different even though they are clone.
Very early in her development, each of Rainbow's cells "turned off" one entire
X chromosome - and therefore, turned off either the black color gene or the
orange one. This process, called X-inactivation, happens normally in females,
in order to prevent them from having twice as much X-chromosome activity as
males. It also happens randomly, meaning that not every cell turns off the same
X chromosome. As a result, Rainbow developed as a mosaic of cells that had
one or the other coat color gene inactivated - some patches of cells specified
black, other patches specified orange, and still others specified white, due to
more complex genetic events. This is how all calico cats, like Rainbow, get
their markings. CC looks different because the somatic cell that Rainbow
donated to create her contained an activated black gene and an inactivated
orange gene. What's interesting is that, as CC developed, her cells did not
change that inactivation pattern. Therefore, unlike Rainbow, CC developed
without any cells that specified orange coat color. The result is CC's black and
white tiger-tabby coat. Rainbow and CC are living proof that a clone will not
look exactly like the donor of its genetic material.