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Cloning
What is a clone? An exact genetic
copy. Offspring are produced
asexually.
There are many different processes and
procedures that can be considered cloning.
They include…
• Natural cloning – Asexual
reproduction of offspring
by cell division. This is the
type of cloning that occurs
naturally in bacteria and
single celled protists
(amoeba, etc)
DNA cloning also called recombinant DNA technology. This
technology has been around since the 1970’s. The scientist cuts
the DNA of interest with a restriction enzyme and inserts it into a
bacterial plasmid and lets it multiply. This will generate enough of
the DNA so it can be studied.
Cloning
• Reproductive cloning – a technology used to
generate an offspring animal using genetic
material from an adult animal cell. Dolly the
Sheep was the 1st mammal cloned in this
manner. Since then cows, dogs, cats, goats and
pigs have been cloned . In 1952, the first animal
cloned was a tadpole. Before Dolly, the first
mammal cloned from the cell of an adult animal,
clones were created from embryonic cells.
Reproductive cloning-Dolly the sheep
• Dolly was created by a reproductive cloning process called
•
“somatic cell nuclear transfer” (SCNT).
– In this process the genetic material from a Somatic cell
– (any type – skin, blood, etc) is transferred to an egg that has
had its nucleus removed. It is then stimulated to produce an
embryo by chemicals or electric current. Then put into a
surrogate mother. A somatic cell ( all cell of the body except
the sperm and egg cell) is used because it has a full set of
chromosomes. Sperm and egg cells only have one set of
chromosomes.
How Dolly was cloned…
Cloning
• Therapeutic cloning – is
the production of cloned
cell for sole purpose of
harvesting stem cells.
– SCNT is performed but
the resulting zygote is not
allowed to grow past the
blastula stage. In this
manner, a patient’s skin
cell could later be
induced to grow new
tissue to replace
damaged heart, nervous,
or muscle cells.