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Insights Into Human Cloning and Technologies Involved
#1
This is post no. 1 under the main topic.
Two technologies possible for human cloning include Artificial embryo twinning and Somatic Cell Nuclear Transfer.

Cloning is the developing of an organism that has a complete genetic makeup of another. The two organisms, the clone and the original organism could be explained better by a scenario of identical twins. Identical twins have similar composition of all their genes therefore, giving them the characteristic of similarity. Over years, clones of different organisms like mice, frogs and pets have been developed. Actually, cloning is dated back to early 1970’s. The cloning of these organisms some of which include mammals has given insight to a notable ability to develop human clones. Actually the prospect of human cloning first came to lame light after the successful cloning of Dolly the lamb in 1997. The implementation of human cloning has not been done due to imbalance in its pros and cons. Nevertheless, clones of numerous other organisms have been developed.

Many clones and the technology itself have proved beneficial and have been accepted in the society. Clones have provided disease models. When infected with disease causing agents they are efficiently used in acquiring insight of the disease. Clones of stem cells have been sufficiently used in repairing of tissues that are damaged. Cloning again has enabled to generate great numbers of transgenic organisms. These are organisms that produce commercially viable products such as proteins. Another applicable advantage of cloning would be in reviving extinct organisms and sustaining species that face danger of extinction. However, reviving the extinct organisms would rather be theoretical than practical, unless undamaged and properly kept DNA samples of the organism are available.

Two technologies possible for human cloning include artificial embryo twinning and Somatic Cell Nuclear Transfer. Artificial embryo twinning technique is similar to the natural procedure of formation of identical twins. Naturally, a zygote divides into two or more cells in the same embryo. Each cell then develops resulting to identical individuals since they are genetically similar. The major difference between artificial embryo twinning and natural procedure lies in the environment used in developing the embryo. The latter occurs in a mother’s body while artificial embryo twinning is done in a Petri dish. Twinning is then done to the embryo resulting to two cells which are then allowed to grow individually in surrogate mother. The developed individuals are genetically identical since they originate from the same zygote.

Somatic cell nuclear transfer yields similar results to artificial embryo twinning although it makes use of ultimately different procedure. Somatic cells are all cells apart from the reproductive cells, the egg and sperm. The nucleus of a somatic cell is isolated and transferred to an egg cell whose nucleus is also removed prior. The egg cell, with its new nucleus develops into an embryo which is placed in surrogate mother for development. The resulting individual or the clone is genetically similar to the nucleus donor. However, it should be noted that the number of chromosomes inherited by the clones in both technologies is different. In artificial embryo twinning, both the sperm and egg donate a chromosome each. The embryo inherits two chromosomes and therefore, the clone ends up with two chromosomes. In somatic nuclear cell transfer, the nucleus of the recipient egg is removed prior to introduction of a new nucleus. Therefore the clone bears only a single chromosome.

These procedures give insight in the ability and possibility of developing human clones. However, the ultimate decision to clone human depends on the pros and cons of the same, which are discussed below. Human cloning would greatly help in medical research by providing absolutely actual environments to study certain medical conditions that have been of concern over years such as, growth of tumors and cancer. The study of cells would again give an insight to human aging. The study of human genetics would be easier and probably more effective, given that models similar to their counterparts are used. Considered a great benefit of this technology would be the ability to replace deceased underage humans, especially children. Children who die in accidents and acute diseases could be replaced. Using the somatic cell nuclear transfer method, nucleus of a somatic cell of the deceased could be isolated and used in developing a clone. Equally, celebrities and people who made great contributions in this world could be sustained by developing clones and therefore, help sustain talents and man power. Infertile couples would be able to bear children of their own kind through Somatic cell nuclear transfer. Again the bearing of twins would be out of human will other than nature. From an unbiased point of view, these benefits outwit the disadvantages of human cloning.

Challenges related to human cloning include; high chances of failure, problems during a later stage in development and abnormal expression of genes. These could probably be fixed as practice goes on. The chances of failure could be attributed to; first, incompatibility between a nucleus and the host egg cell. Secondly, it is not guaranteed that an egg induced with a foreign nucleus could definitely divide. Thirdly, failure could occur in introducing an embryo to the surrogate mother and/or further development in the surrogate mother could fail. Assuming that a certain clone is delivered, its normality cannot be predicted. Most clones suffer from “Large Offspring Syndrome’’. This is a condition whereby, a clone at birth will have larger organs than their natural counterparts. Organ malformations are also rampant hence severe complications later in life. Another challenge is that a clone could fail to express a required gene at the right place and in the right time. Failure to express the right gene at the right place and time could cause complications such as untimely aging and death. Therefore, there is never any estimated lifespan of a clone.

Prospects in human cloning face several challenges which include; legal, social and ethical issues. However, any technology that relieves human pain and trauma would be much welcome to the society. As the technology become successful, human would probably drop criticism and embrace it. It is recommended that, before arguing against human cloning and terming it as impunity, the positive impacts of this technology should be considered.
 
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#2
This is post no. 2 under the main topic.
I would like to discuss more closely the chromosome division issue in both techniques taking human model as an example. During artificial embryo twinning technique, the process begins with creating a zygote, the fertilized egg cell which contains 46 chromosomes (23 acquired from egg nucleus and 23 from spermatozoid nucleus). Before the zygote divides, the genetic material (DNA) replicates, providing both daughter cells with the same amount of genetic material (46 chromosomes). If we then separate the cells, and grow one of them in a Petri dish, we will get a cloned human with the same genetic material as the other, naturally born human.

The other technique, somatic cell nuclear transfer, is more complex, more artificial, and accompanied with more side effects. Namely, the genetic material (nucleus) is removed from the somatic cell, and inserted in emptied egg cell. Now the egg cell becomes the first cell of a new, cloned organism. The only correction I would suggest is that the number of chromosomes is not reduced using this technique, as the nucleus of somatic cell has 46 chromosomes, unlike the nucleus of egg cell and sperm cell (23 chromosomes). The clone developed by using this technique would have the exact same properties as the human from whom the somatic cell nucleus is taken, and his biological parents would be the parents of that human.

There are many issues concerning cloning of living organisms as suggested in the above article. A high incidence of failed cloning is possibly due to reprogramming of somatic cell DNA in the egg cell environment, although this process is not yet uncovered. That results in DNA changes and subsequent discoordinations during the complex process of organism development.

It is well established that mitochondrial DNA plays an important role in human organism and its defects are involved in broad range of neurological and other diseases. During the process of somatic cell nuclear transfer, the mitochondria are not being transferred, so the egg cell mitochondria take action. That can cause different problems, but this issue has not yet been well investigated.
Sasa Milosevic
 
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