What We Know:
- Gene cloning, also called DNA cloning, creates copies of genes, or segments of DNA.
- Reproductive cloning makes duplicates of whole animals.
- Therapeutic cloning creates embryonic stem cells, which are used to create tissues that can repair or replace damaged tissues. – https://www.livescience.com/58079-cloning-facts.html
1952 – Scientists demonstrate they can remove the nucleus from a frog’s egg, replace it with the nucleus of an embryonic frog cell, and get the egg to develop into a tadpole.
Do clones ever occur naturally?
Yes. In nature, some plants and single-celled organisms, such as bacteria, produce genetically identical offspring through a process called asexual reproduction. In asexual reproduction, a new individual is generated from a copy of a single cell from the parent organism.
Natural clones, also known as identical twins, occur in humans and other mammals. These twins are produced when a fertilized egg splits, creating two or more embryos that carry almost identical DNA. Identical twins have nearly the same genetic makeup as each other, but they are genetically different from either parent. – https://www.genome.gov/25020028/cloning-fact-sheet/
How are genes cloned?
Researchers routinely use cloning techniques to make copies of genes that they wish to study. The procedure consists of inserting a gene from one organism, often referred to as “foreign DNA,” into the genetic material of a carrier called a vector. Examples of vectors include bacteria, yeast cells, viruses or plasmids, which are small DNA circles carried by bacteria. After the gene is inserted, the vector is placed in laboratory conditions that prompt it to multiply, resulting in the gene being copied many times over. – https://www.genome.gov/25020028/cloning-fact-sheet/
How are animals cloned?
In reproductive cloning, researchers remove a mature somatic cell, such as a skin cell, from an animal that they wish to copy. They then transfer the DNA of the donor animal’s somatic cell into an egg cell, or oocyte, that has had its own DNA-containing nucleus removed.
Researchers can add the DNA from the somatic cell to the empty egg in two different ways. In the first method, they remove the DNA-containing nucleus of the somatic cell with a needle and inject it into the empty egg. In the second approach, they use an electrical current to fuse the entire somatic cell with the empty egg.
In both processes, the egg is allowed to develop into an early-stage embryo in the test-tube and then is implanted into the womb of an adult female animal.
Ultimately, the adult female gives birth to an animal that has the same genetic make up as the animal that donated the somatic cell. This young animal is referred to as a clone. Reproductive cloning may require the use of a surrogate mother to allow development of the cloned embryo, as was the case for the most famous cloned organism, Dolly the sheep. – https://www.genome.gov/25020028/cloning-fact-sheet/
What animals have been cloned?
Over the last 50 years, scientists have conducted cloning experiments in a wide range of animals using a variety of techniques. In 1979, researchers produced the first genetically identical mice by splitting mouse embryos in the test tube and then implanting the resulting embryos into the wombs of adult female mice. Shortly after that, researchers produced the first genetically identical cows, sheep and chickens by transferring the nucleus of a cell taken from an early embryo into an egg that had been emptied of its nucleus.
It was not until 1996, however, that researchers succeeded in cloning the first mammal from a mature (somatic) cell taken from an adult animal. After 276 attempts, Scottish researchers finally produced Dolly, the lamb from the udder cell of a 6-year-old sheep. Two years later, researchers in Japan cloned eight calves from a single cow, but only four survived.
Besides cattle and sheep, other mammals that have been cloned from somatic cells include: cat, deer, dog, horse, mule, ox, rabbit and rat. In addition, a rhesus monkey has been cloned by embryo splitting. – https://www.genome.gov/25020028/cloning-fact-sheet/
Do cloned animals always look identical?
No. Clones do not always look identical. Although clones share the same genetic material, the environment also plays a big role in how an organism turns out.
For example, the first cat to be cloned, named Cc, is a female calico cat that looks very different from her mother. The explanation for the difference is that the color and pattern of the coats of cats cannot be attributed exclusively to genes. A biological phenomenon involving inactivation of the X chromosome (See sex chromosome) in every cell of the female cat (which has two X chromosomes) determines which coat color genes are switched off and which are switched on. The distribution of X inactivation, which seems to occur randomly, determines the appearance of the cat’s coat. – https://www.genome.gov/25020028/cloning-fact-sheet/
Have humans been cloned?
Despite several highly publicized claims, human cloning still appears to be fiction. There currently is no solid scientific evidence that anyone has cloned human embryos.
In 1998, scientists in South Korea claimed to have successfully cloned a human embryo, but said the experiment was interrupted very early when the clone was just a group of four cells. In 2002, Clonaid, part of a religious group that believes humans were created by extraterrestrials, held a news conference to announce the birth of what it claimed to be the first cloned human, a girl named Eve. However, despite repeated requests by the research community and the news media, Clonaid never provided any evidence to confirm the existence of this clone or the other 12 human clones it purportedly created.
In 2004, a group led by Woo-Suk Hwang of Seoul National University in South Korea published a paper in the journal Science in which it claimed to have created a cloned human embryo in a test tube. However, an independent scientific committee later found no proof to support the claim and, in January 2006, Science announced that Hwang’s paper had been retracted.
From a technical perspective, cloning humans and other primates is more difficult than in other mammals. One reason is that two proteins essential to cell division, known as spindle proteins, are located very close to the chromosomes in primate eggs. Consequently, removal of the egg’s nucleus to make room for the donor nucleus also removes the spindle proteins, interfering with cell division. In other mammals, such as cats, rabbits and mice, the two spindle proteins are spread throughout the egg. So, removal of the egg’s nucleus does not result in loss of spindle proteins. In addition, some dyes and the ultraviolet light used to remove the egg’s nucleus can damage the primate cell and prevent it from growing. -https://www.genome.gov/25020028/cloning-fact-sheet/
‘Cloning may make it possible to save endangered species from becoming extinct.
The first successfully clones animal was Dolly, a sheep that was born in 1996, in Edinburgh, Scotland, at the Roslin Institute under the guidance of Ian Wilmut and his colleagues. There were 277 attempts before Dolly was successfully cloned.
Plants such as strawberry plants have been cloning themselves for billions of years. Strawberry plants clone by shooting out a runner, which then grows its own root and begins to produce strawberries. Onions, potatoes, and even grass clones in a similar manner.
People have been cloning plants since the beginning of agriculture. This is done by taking a clipping of a plant and growing it into a new plant.
Tissue culture propagation is done by breaking up specialized roots and growing the root cells in a rich culture. The plants that grow are identical to the originals.
Some creatures in the wild are able to clone, including some worms, frogs, lizards, and fish, under the right conditions. This type of cloning is referred to as parthenogenesis.
Identical twins are a type of natural occurring cloning process. The children are not clones of their parents but they are clones of each other.
Cloned animals have shown to have health issues such as defects in the heart, liver, and brain, as well as increased birth size. They also age faster, and have immune system issues. Dolly the sheep only lived to be 6 years old when the normal life span of a sheep if 12 years.
Embryonic stem cells can be used to generate healthy tissue in a laboratory, which may help to heal sick and dying people. These stem cells can be produced through embryonic cloning but there is a moral debate about its use as well as other concerns about its safety.
Cloning might help sterile couples have genetic offspring. Cloning of humans however carries many issues in society and religion about human life and identity. It is an ongoing debate.
Species that have been cloned include tadpoles, carp, mice, sheep, rhesus monkeys, pigs, guar, cattle, mules, horses, dogs, wolves, water buffalo, camels, and others.
There have been many movies made about the possibilities cloning may provide, such as Jurassic Park. Star Wars Clone Wars, The Island, and Resident Evil. – http://www.softschools.com/facts/science/cloning_facts/3204/
1. The first cloning of an animal was done in the 1880s by German biologist Hans Driesch who cloned a sea urchin from an embryo cell.
2. In 1952, Robert Briggs and Thomas King cloned northern leopard frogs…
3. …but it was not until 1963 that biologist JBS Haldane coined the term “clone”.
4. The reproductive cloning of humans is banned under the EU Charter of Fundamental Rights.
5. Dolly the Sheep, the first mammal to be cloned from an adult cell, was born on July 5, 1996. The cell was taken from a mammary gland…
6. She was named ‘Dolly’ as, in the words of the project leader: “We couldn’t think of a more impressive pair of glands than Dolly Parton’s.”
The reproductive cloning of humans is banned under the EU Charter of Fundamental Rights
7. The first dog to be cloned was born in South Korea on April 24, 2005, and was named Snuppy.
8. Snuppy was named as Time Magazine’s most amazing invention of 2005.
9. The team that produced Snuppy went on to create the world’s first cloned sniffer dogs in 2007.
10. The six dogs, all named Toppy, started work for South Korea’s customs service in 2009. – https://www.express.co.uk/life-style/top10facts/424095/Top-10-facts-about-clones
Pros and Cons
Cloning a human being is a big step. Right since the cloning of Dolly, the interest in cloning a human being has been on the rise in the scientific community. But we need to know its pros and cons before we can form an opinion about its rationality.
- Infertility Treatment: Human cloning could be a blessing for infertile couples, as reproductive cloning does not involve the fusion of the sex cells.
- Treating Diseases: As already discussed, therapeutic cloning can be used to treat a number of degenerative diseases like those of the nervous system, spinal cord injury, and organ failure. Also who knows, it could also be used to regenerate whole limbs. This would provide a life-changing line of treatment for amputees.
- Replacing Defective Genes: Defective genes would cause sickness in an individual, irrespective of how healthy a lifestyle he leads. Advances in human cloning will help him to replace the defective genes with healthy ones.
- Cosmetic Treatment: Relieving individuals of the diseases that are caused due to plastic or cosmetic surgery is another benefit of the cloning process.
- Low Success Rate: Cloning technology is still at an infant stage. Experiments with animals show that the success rate of animal cloning is quite low. More than 90% of the efforts to produce a viable offspring in animals have failed.
- Disorders in Off-springs: Cloned animals tend to have a weak immune system due to which they are prone to infections. Such organisms often show tumorous growth, other disorders, and tend to die young. For example, a group of Japanese scientists who had cloned a dozen mice reported that the animals died early.
- Expensive and Extensive Procedure: Cloning Dolly involved 277 eggs. Out of them, only 30 started to divide and 9 induced pregnancy. Only 1 out of them survived.
These attempts with grave consequences cast a cloud of doubt over the rationality of cloning human beings. – https://biologywise.com/human-cloning-facts
What We Don’t Know:
Should people be allowed to clone themselves?
Is it okay to introduce non-human DNA in our genome?
Should parents be allowed to design their babies?
What are the most important areas of scientific research?
Should people be forced to die once indefinite lifespans are achieved?
Speculation And Theory:
Some People Believe This Technology Is Alot Farther Along Than The General Public Is Aware Of: