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.