Introduction to cloning

Cloning
Definition
Cloning is the process of producing similar populations of genetically identical
individuals that occurs in nature when organisms such as bacteria, insects or
plants reproduce asexually.
Introduction to cloning
When is cloning done?
Cloning is done to amplify the DNA fragments containing the gene of interest and
ensures pure sample of gene. When the concentration of the required gene
products (proteins) is very low, the production of multiple clones makes it easy to
obtain large quantity of the gene products.
What all can be cloned?
Cloning is a powerful technique that can be implemented to obtain clones of
genes (molecular cloning), cells (cell cloning) and organisms (organism cloning).
ne cloning, which creates copies of
genes or segments of DNA Reproductive cloning, which creates copies of whole
animals Therapeutic cloning, which creates embryonic stem cells. Researchers
hope to use these cells to grow healthy tissue to replace injured or diseased
tissues in the human body
What are the requisites for cloning?
In biotechnology, cloning requires a gene of interest, a vehicle (vectors) to carry
the gene, a host to provide an environment for multiplication of genes and a
medium for growth of the host strain.
What is DNA cloning?
DNA cloning is the procedures to produce multiple copies of a single gene or
segment of DNA. A DNA fragment containing the gene of interest is isolated from
chromosomal DNA using restriction enzymes and then united with a plasmid that
has been cut with the same restriction enzymes. When the fragment of
chromosomal DNA is joined with its cloning vector in the lab, it is called a

"recombinant DNA molecule." Following introduction into suitable host cells, the
recombinant DNA can then be reproduced along with the host cell DNA.
What are the steps involved in cloning?
The major steps involved in cloning a gene are:
1. Preparation of carrier DNA (vector DNA).
2. Isolation of the desired gene.
3. Insertion of the isolated gene into the vector (which results in the rDNA).
4. Transformation of rDNA into a suitable host.
5. Expression of rDNA (cloned gene).
CLONING VECTORS-
Cloning vectors are self-replicating DNA, that is used to carry our gene of interest
into a host system where the gene is then expressed. There are many cloning
vectors used in cloning procedures. Usually, the following are used:
1) Plasmids.
2) Bacteriophages

3) Bacterial artificial chromosomes
4) Yeast artificial chromosome.
Cloning in medicine
Cloning for medical purposes has the potential to benefit large numbers of
people.
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 disease-causing mutations in their genes. Creating these transgenic animals
is a time-intensive process that requires trial-and-error and several generations of
breeding. Cloning could help reduce the time needed to make a transgenic animal
model, and the result would be a population of genetically identical animals for
study.
Cloning to make stem cells
Stem cells build, maintain, and repair the body throughout our lives. Because
these are processes that stem cells do naturally, they can be manipulated to
repair damaged or diseased organs and tissues. But stem cells transferred from
one person to another (such as in a bone marrow transplant) are seen as foreign,
and they usually trigger an immune response.
Some researchers are looking at cloning as a way to create stem cells that are
genetically identical to an individual. These cells could then be used for medical
purposes, possibly even for growing whole organs. And stem cells cloned from
someone with a diseasecould be grown in culture and studied to help researchers
understand the disease and develop treatments.
In 2013, scientists at Oregon Health and Science University were the first to use
cloning techniques to successfully create human embryonic stem cells. The donor
DNA came from an 8-month-old with a rare genetic disease.

Reviving endangered or extinct species
You might have seen the Jurassic Park movies. In the original feature film, based
on the Michael Crichton novel, scientists useDNA preserved for tens of millions of
years to clone dinosaurs. They run into trouble, however, when they realize that
the cloned creatures were smarter and fiercer than expected. Could we really
clone dinosaurs?
In theory? Yes. You would need:
 A well-preserved source of DNA from the extinct dinosaur, and
 A closely related species, currently living, that could serve as an egg donor and
surrogate mother.

In reality? Probably not.
It's extremely unlikely that dinosaur DNA could survive undamaged for such a
long time. However, scientists have been working to clone species that became
extinct more recently, using DNA from well-preserved tissue samples. A number
of projects are underway to clone extinct species, including the wooly mammoth.
In 2009, scientists had their first near-success resurrecting an extinct animal.
Using goats as egg donors and surrogates, they made several clones of a wild
mountain goat called the bucardo—but the longest-surviving clone died soon
after birth. Even if the effort eventually succeeds, the only frozen tissue sample
comes from a female, so it will only produce female clones. However, scientists
speculate they may be able to remove one X chromosome and add a Y
chromosome from a related goat species to make a male.
Cloning livestock
Programs are underway to clone agricultural animals, such as cattle and pigs that
are efficient producers of high-quality milk or meat.
A group of researchers at Utah State University led by Dr. Ken White, Dean of
College of Agriculture & Applied Science, have been able to clone steer from
slaughterhouse carcasses. Their aim isn't to produce animals for consumption—
cloning is far more labor-intensive and expensive than conventional breeding
methods. Instead, they want to use these animals as breeding stock.
The important thing to know about beef cattle is that the quality and yield of their
meat can be assessed only after they are slaughtered. And male animals are
routinely neutered when they're a few days old. That is, their testes are removed,
so they are unable to make sperm. But cells from a high-quality carcass can be
cloned, giving rise to an animal that is able, though conventional breeding
methods, to pass its superior genes to its offspring.
Scientists have also cloned mules, a reproductively sterile hybrid of a male donkey
and a female horse; dairy cows; and horses. One gelded racing horse, a male
whose testes have been removed, has a clone that is available for breeding. Some
of the cloned cows produce about twice as much milk as the average producer.
And a cloned racing mule is ranked among the best in the world.

Drug production
Farm animals such as cows, sheep, and goats are being genetically engineered to
produce drugs or proteins that are useful in medicine. As an example, scientists
could take cells from a cow that produces largeamounts of milk and grow them in
culture. Then they could insert a gene into the DNA of these cells that codes for a
drug or a vaccine. If they take the nucleus from one of these cells and transfer it
to a cow egg, it could develop into a cow that makes the drug in its milk. Since
every cell in the cow would carry the drug gene, it could pass the gene to its
offspring, creating a whole herd of drug-producing cows. Even better, we could
avoid the issueof the genetic reshuffling that happens during sexual reproduction
and simply clone our drug-producing cow.

Cloning humans
The prospect of cloning humans is highly controversial, and it raises a number of
ethical, legal, and social challenges that need to be considered.
The vast majority of scientists and law makers view human reproductivecloning—
cloning for the purposeof making a human baby—immoral. Supporters see it as a
possible solution to infertility problems. Some even imagine making clones of
geniuses, whose work could advance society. Far-fetched views describe farms
filled with clones whoseorgans are harvested for transplantation—a truly horrific
idea.
For now, risks and technical challenges—as well as laws that make it illegal—will
probably keep human reproductive cloning from becoming a reality. Even though
many species havebeen cloned successfully, theprocess is still technically difficult
and inefficient. The success rate in cloning is quite low: most embryos fail to
develop, and many pregnancies end in miscarriage.
Currentefforts at human cloning are focused on creating embryonic stem cells for
research and medicine, as described above. However, many feel that this type of
therapeutic cloning comes dangerously close to human reproductive cloning. And
once techniques become more streamlined and efficient, they fear that some may
be tempted to take that next step. From a technical and moral standpoint, before
human cloning becomes routine, we need to have a good idea of the risks
involved.

Ethical issues
Religious Belief and Control
Cloning goes against the basic belief of certain religions that only God has created
life and its various forms in nature. Humans cannot act as God. Even when
genetically identical twins are born, their embryo splits spontaneously or
randomly to give a new unique genetic combination. Cloning involves a controlled
split of the embryo to producea tailor-made genetic makeup. Ethically, it is wrong
for any human to have control over the genetic makeup of any other individual.
More so, the cloned individual would be generated for specific purposes. This in
essence is wrong wherein the purpose of an individual's life should be more than
just satisfying someone else's needs.
Relationships and Individuality
Cloning creates a new human, yet strips him off his individuality. A man, along
with his clone can never be dignified as a single identity. The uniqueness
attributed to humans from God might be at stake. The replication of an individual
is a major blow to his most distinct feature - his identity. Another fact is that we
are unsure how the cloned individual might react and behave with regards to his
family and parents.
Legal and Other Issues
Altering Gene Pool
If cloning becomes widespread, the genetic diversity of humans will go down. This
would result in the decrease in immunity of humans against diseases. Thus
making humans susceptible to epidemics and unknown diseases. Some advocate
human cloning as ethically unacceptable because it is seen as a threat to the
entire human evolution.
Illegal Cloning and Clones
Cloning could have legal implications as well. A cloned child having multiple
donors might complicate parental right issues as well as inheritance and marital
eligibility issues. Another view held by many experts, suggests that there is a
possibility of clones being developed without the concerned individual's consent.

This will definitely create legal issues not to mention violation of medical as well
as moral ethics. Many people are also concerned that clones would be produced
with a specific need and purpose in mind and such cloned individuals would be
traded or sold, amounting to human trafficking which is illegal.
Advantages of cloning
Organ Replacement
This form of cloning allows scientists to take a small amount of cells from an
organ, and harvest an entirely new, functioning one. This is extremely beneficial
because of the large amount of people that are on an organ donor waiting list.
Cloning Help Infertile Couples to Have Children
Fertility problems could also be potentially eased with the use of genetic cloning.
The child could have DNA and qualities from both parents, instead of just one.
With this cloning, somatic cells are acquired from male with female eggs and
surrogate mother. The process normally includes the extraction of nucleus in the
somatic cell. Then, somatic cells are inserted in the egg. Afterwards, the egg is
stimulated and an embryo is developed. It is also inserted in the surrogate
mother, wherein she needs to carry it for nine months.

The Benefits of Growing Eminent Persons
Very influential and historical people could possibly be recreated. People such as
Albert Einstein and Martin Luther King Jr. could, theoretically, be brought back to
life to educate and help people in today’s world.
Disadvantages of cloning
Human can live on the Earth relies on the diversity of genes. And the diversity of
genes comes fromparents having different sets of genes. The mosthorrendous
part of identical genes is that it will weaken our power and adaptations, which
make us subjected to great diseases easily. In addition, human cloning is just
copying the identical genes, which means it will decrease the diversity of genes.
Furthermore, the beauty of humanity lies in the differences we see in each other.
Cloning would eliminate surprise and predict expectancy.
As mentioned above, in human cloning, all human beings will be identical.
Which means that entire human is at a risk of getting infected by the same type
of pathogen. In scientific point of view, if everyone has the same type of genes
and they are closed to each other they may not defend against the same kind of
serious disease. Then cloning will be detrimental in terms of a great disaster.
Another negative effect of cloning is inbreeding, as everyone has the same
genotype and keep reproducing among themselves. This would lead us to our
own extinction finally.

Introduction to cloning

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Introduction to cloning