When a whole organism is reproduced from the parent organisms’ single cell and in a genetically identical manner, then animal cloning is said to have taken place. The cloned animal is thus an exact copy of the parent organism owing to the same exact DNA structure and composition. Cloning happens in nature at times. The development of twins who come from a single fertilized egg is a classical example of cloning. Biological technology has developed over the years and as such, it has become possible to clone animals artificially. With this advancement in technology, there are advantages and disadvantages of cloning.
For a long time, scientists struggled to clone animals, but it all hit dead ends. Sometimes the clones did not make it to adulthood. However, it brought the technology closer to its success. A good example is that of cloning tadpoles from frogs. The cloning was done through nuclear transfer. The cloning was almost successful until the tadpoles died before growing to maturity. By employing the same technique, scientists produced clones of mammals but then again, they did not make it to maturity. The scientists did not give up hope and after several attempts; a successful cloning took place in that of Dolly the sheep. Dolly, the sheep grew to maturity and actually reproduced naturally. With this great step in animal cloning, scientists went ahead and cloned a variety of animals including pigs, rats, cats and horses.
Animal cloning has advanced since the time of the Dolly sheep. Initial attempts involved using embryonic cells. First, extraction of the DNA nucleus from an embryonic cell was done then entrenched into an unfertilized egg. This unfertilized egg must be free from a nucleus hence the nucleus had to be removed prior to the inclusion of the DNA nucleus. An electric shock is what stimulated fertilization. Sometimes, chemicals were used to facilitate fertilization. After the artificially induced union led to the development of cells, the cells were then transferred and implanted into a host mother. What came out of this process was an organism that looked exactly the same in make up as the original cell. Since the time of Dolly the sheep, animal cloning has moved from clones of just embryonic cells to clones of non embryonic cells. Animal cloning is now done not just for reproductive purposes but for non reproductive purposes as well. In non reproductive case, cloning is done for recreating damaged cells or healing damaged organs; actually the intention is not to copy the whole organism.
Animal cloning has brought about many advantages. In the earlier years of cloning, the desire to have useful and outstanding characteristics was the in thing. Nowadays, farmers would like to do animal cloning to reduce the time and effort that were previously needed to select and propagate the best of the herds. The success of propagating from ancient times was only 2% hence with cloning in place; everyone was looking forward to applying the biological technology which was a sure way to success. There is still a brighter future for cloning. Farm animals can be cloned and used as a large scale source of medically vital proteins. An example is Polly, who produces milk rich in factor IX that is a protein deficient in hemophiliacs. Polly is a lamb that was produced by cloning.
In as much as scientists take pride in the achievements made so far with animal cloning, some people are quite uncomfortable with this biological technology for what they term as valid reasons. Animal cloning has failed in some instances and led to the birth of animals with defects. In other instances, the pregnancy fails even before the organism is born. A case in point is where a cow gave birth to a two-faced calf due to cloning.
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