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Medical Video: Could we clone humans? | Earth Lab
Cloning is the process of taking genetic information from one living creature to create identical copies of it. Maybe you can imagine cloning as a color photocopy. Genetics have succeeded in cloning cells, tissues, genes, and even living animals. Will later human cloning be possible?
Check out a number of interesting facts below about cloning that you might never know before.
1. Dolly the Sheep is not the first cloned animal in the world
The history of cloning actually began more than 50 years ago. The animal that was first cloned was a sea urchin in 1880 by a researcher named Hans Driesch.
A few years later, the first cloned live mammals were finally exhibited to the public in 1997. Who doesn't know Dolly the Sheep? Dolly was actually born on July 5, 1996 in Scotland. Dolly was cloned using a single cell taken from a donor sheep. Finn Dorset sheep has a life span of up to 12 years, but Dolly was forced to die in 2003 due to chronic lung disease and premature arthritis. However, Dolly's cloned siblings: Debbie, Denise, Dianna, and Daisy are still alive today.
Seeing the success of Dolly's cloning, more and more researchers are competing to create cloned animals. A group of research teams produced cows, sheep, chickens, all three of which had identical genetic codes by transferring cell nuclei taken from donor embryos to eggs that had been emptied from the core. In North Korea, researchers managed to clone a cell from Chase, a state-owned retired sniffer dog, and produced a force of six powerful sniffer dogs to work in the police force since 2009.
2. Oranges are cloned fruit
Some plants and single-celled organisms such as bacteria produce genetically identical offspring through the process of asexual reproduction. In asexual reproduction, new individuals are produced from copies of a single cell from the parent organism.
Did you know that orange is a cloned fruit? One orange variety called the navel has a bulge in the base of an orange, which is similar to a human navel. This bulge is actually the second remaining growth of fruit. All navel oranges are cloned from each other. Navel oranges are not seeded, which means they cannot reproduce themselves. That means navel oranges only need to be transplanted from each other to make new trees.
3. The results of cloning don't always look like twins
Cloning doesn't always look the same. Although the results of cloning share the same genetic material with donors, the environment also plays a large role in how organisms eventually form.
For example, the first cloned cat, Cc, is a Calico race female cat that has a very different appearance from its mother. This is because the color and pattern of cat fur is not directly affected by genetics. The phenomenon of X chromosome deactivation in female cats (which have two pairs) determines the color of their feathers - for example orange, or black and white. Distribution of X chromosome deactivation that occurs randomly throughout the body then determines the overall appearance of the fur pattern. For example, the cat has dark orange fur on some sides while also having bright white or orange stripes all over its body.
4. But, twins are the result of human cloning
Human cloning is often said to be an impossible thing to do, at least for the next several decades. But this is not really true. Cloning is basically individuals who have identical genetic codes. Identical twins are the result of cloning because they share DNA chains and almost identical genetic codes.
Usually, after sperm and egg cells meet, the fertilized cell will begin to divide in one group into two, four, eight, 16, and so on. These cells gradually develop into organs and organ systems that produce one fetus in one pregnancy. Sometimes, after the first division, these two cells continue to separate themselves and then grow into two individuals with the same genetic code - identical twins, aka clones.
The process of human cloning experienced by identical twins is the will of nature that cannot be contested, even though it is still unknown what the cause is. So, what about artificial human cloning, which must go through laboratory procedures? Is this possible?
5. Human cloning, can it be done?
In December 2002, the first human clone, a baby girl named Eve, was claimed to have been successfully created by Clonaid. Clonaid also claimed to have succeeded in creating the first baby boy through cloning, whose tissue was allegedly taken from a child killed in a car accident. But even though it was constantly pushed by the research community and the media, Clonaid was never able to prove the existence of these two babies or the other 12 human clones that were said to be made.
In 2004, a research group led by Woo-Suk Hwang of Seoul National University in South Korea published a paper in the journal Science where he claimed to have created cloned human embryos in test tubes. However, the independent scientific committee later found no evidence to support the claim and in January 2006, the journal Science announced that Hwang's paper had been withdrawn.
From a technical point of view, cloning of humans and other primates will be more difficult than mammals. One reason, in primate egg cells, there are two important proteins for cell division known as spindle proteins. The spindle protein is located very close to the chromosomes in primate eggs. As a result, removing the egg core to make room for the donor nucleus will also eliminate spindle proteins. This disrupts the process of cell division.
In other mammals, such as cats, rabbits, or mice, two protein spindles are spread throughout the egg cell. So, removal of the egg nucleus does not result in loss of spindle protein. In addition, some dyes and ultraviolet light used to lift the egg nucleus can damage primate cells and prevent them from growing.
