The Science Behind The Cloning Of The Monkeys Free Essay Example

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The Breakthrough

The successful cloning of primates for the first time is an extremely significant scientific breakthrough. On January 24th, 2018, the Cell Journal reported the news to the Western world that a Chinese research team at the Chinese Academy of the Sciences, located in Shanghai, and led by Dr Ming Poo, had cloned two healthy macaque monkeys through the utilisation of the somatic cell nuclear transfer method (SCNT); the same method used to clone Dolly the sheep in 1996. The application of the method on mammals has been scientific commonplace over the past two decades, due to the cloning of many animals, such as domesticated dogs, though it is the application of SCNT to clone primates which represents a great expansion upon this knowledge.

For years the cloning of primates has been a notorious process, as many scientists have attempted a failed, though a resolution to the failure could not be found. As described when interviewed for an article, researcher Calvin Simerly (2003) said, “When cells divide, there are just basic things that are supposed to happen, and they just didn’t”

Fortunately, two decades of research came into fruition and the Chinese research team overcame this through experimental trial and error, though the process is not flawless; a total of 63 surrogates combined for 28 pregnancies, yielding four babies, though only two of these were healthy and survived long-term.

Background

The science behind the breakthrough is highly complicated, as demonstrated by the stumping of many top scientists over the past twenty-years. To begin, somatic cell nuclear transfer must be fully understood. It relies upon the principles of how a cell functions. Found in the middle of the animal cell is a nucleus which contains the genetic makeup of the animal, through molecules of DNA and is accountable for the cell division and production of proteins. To produce a clone of a desired animal, the DNA is necessary, therefore the nucleus of the animal is needed. Commencement of the somatic cell nuclear transfer process begins with removing a section of healthy tissue from the monkey that is intended to be replicated. From the tissue a cell will be removed; this cell has to be a somatic cell and not a reproductive cell because somatic cells are the building blocks of mammals as they are responsible for the composition of the skin, blood, connective tissue and organs. Researchers use this somatic cell as the grounds for the creation of the clone. From the somatic cell the nucleus (containing the genetic makeup of the desired monkey) is removed. Meanwhile, scientists also remove the nucleus from an egg cell which is classed as ‘immature’; an oocyte. This means that the egg cell is halted at the beginning of its’ first cell divisions, and by taking away its nucleus the cell is stripped of its’ DNA. This allows the scientists to inject the original nucleus of the desired monkey inside of the bare oocyte. With the egg cell now containing a nucleus, development can continue once again. The normal process of the cell division occurs, as the cell begins to form a structure that is consistent with every mammal in the first stages of development known as a blastocyst. Within this blastocyst a mass of cells will begin to form (known as an inner cell mass). This mass of cells within the blastocyst will is what provides the structure of the fetus within the egg cell. It is from this that scientists are able to produce the embryonic stem cell. These embryonic stem cells are implanted into the mother for surrogacy, and live birth is given as if it was under normal circumstances.

Unsuccessful cloning of monkeys has been a staple of many scientists work since 1996. Although, in 1999 a rhesus macaque named Tetra was ‘cloned’, this breakthrough is significantly more important as the researchers at Primate Research Center based in Oregon, used a method called ‘embryo-splitting’, in which the embryo the split into identical embryos – more of a method of artificial twinning instead of cloning. That method allows several different clones to be created at once, whereas SCNT theoretically can produce an infinite amount. Inspiration derived from the cloning of Dolly through SCNT inspired the successful cloning of many mammals, though those who attempted the cloning of primates failed, not knowing why they were failing. A large breakthrough occurred in 2003 when Calvin Simerly’s team of researchers could finally put reasoning behind their failures, though it still took fifteen more years to resolve the issues. In an article from the Scientific American in 2003, research of the failures from the University of Pittsburgh’s Medical School was published. The team created 716 different monkey embryos, studying their development around the clock, though only thirty-three were placed into their surrogate mothers once they had begun the process of cell division. These cells were seemingly developing as intended, but when not a single embryo gave the result of a pregnancy, researcher Calvin Simerly decided to carefully inspect their progress. Upon inspection, they were surprised to see that everything was not as it seemed; the eggs were very highly abnormal. A decision was made to utilise antibody tags, as this would allow them to carefully monitor the development of the cells, observing both the DNA and proteins. The observation of the cells brought them to the conclusion that the mitotic spindles, which are vital for dividing chromosomes, during mitosis, into their daughter cells, were not operating as expected. This left many cells with an overload, or lack, of chromosomes. This was due to loss of two proteins inside of the spindles during the process of removing the nucleus; other mammals had succeeded as they contained several of these proteins within the nucleus. Furthermore, several other trials of cloning monkeys discovered that the DNA was bunching up, tagging and spooling. Through a combination of these many factors, monkey cloning remained impossible; until this year.

Dr Poo’s research team trialed many solutions to the problem, before eventually finding one that produced two healthy babies. With the new advancements in technology, the team successfully removed the nucleus without losing the spindle proteins. The team also injected the embryos with KDM4d mRNA (an RNA-dependent enzyme, that is encoded in humans by the gene KDM4D) in order to remove the presence of H2K9me3 from the egg. Furthermore, they placed the eggs into trichostatin A, in an attempt to bathe them to stop the bunching of the DNA. Inside of the trichostatin A, the eggs were also prodded, producing enzymes which in turn unlocked genes in the embryo by removing chemical tags. This greatly increased the team’s success, as it improved the development of the blastocyst, enhancing the pregnancy rates within the surrogates. Moreover, the two healthy babies were part of a batch which had fibroblasts from fetus’ added to them – this supposedly aided with the stromal tissues of the monkeys.

The Future

As research into cloning ever increases, as does the success rate, the future of cloning may look extremely positive to scientist, though unfortunately research could possibly become halted, as society and the government begin to look at the ethics of creating ‘artificial’ monkeys. Currently though, the Chinese research team holds several aspirations for the utilisation of this cloning breakthrough. As humans and monkeys are both primates, they hold a significant biological similarity. So similar, that in a report of a study from the University of Washington, St. Louis, Caroline Arbanas (2007) states, “that the three primate species [macaque monkeys, chimps and humans] share about 93 percent of the same DNA”.

This is notable, as the research team performed the cloning on the Macaca fascicularis, more commonly known as the ‘crab-eating macaque’.As of now, the research team intends to use this breakthrough to generate an entire population of monkeys that hold an identical genetic makeup. With outbreaks of diseases occurring quite frequently, this population of monkeys leaves scientists with viable test subjects for potential cures. Due to the identical genetic makeup, scientists will have to overcome less variables as hypothetically they would respond to these cures in the same manner, or at least in a similar fashion. This can decrease the time taken to create and test a cure, increasing the chances of saving many human lives. Moreover, the monkeys will allow scientists to create living disease models, in an attempt to speed up creation of treatments for complex diseases such as Parkinson’s, Alzheimer’s and cancer. Scientists currently use mice as disease models, though several times a therapy has worked on mice but completely failed on humans, due to a lack of genetic similarity between a mouse and a human. Unlike mice, monkeys share a high genetic similarity to humans, and therefore they will be the perfect solution to the live disease model issue. Through the use of gene editing techniques, researchers intend to produce monkeys with the genetic defects or mutations that result in cancer, Alzheimer’s and Parkinson’s. This allows them to create a highly accurate (to a human) model of an affected brain, that can be studied and tested upon. Although this may be immoral, it could potentially save thousands of lives. Furthermore, future research may be directed towards the cloning of human beings. Though this the ethics of this are extremely questionable as many would oppose the cloning of humans, and it would have to be passed through government as legislation. So, currently, the chances of future research occurring are slim. Though researchers do have the exciting opportunity to manufacture human life. While cloned humans may be detrimental to society, it would allow scientists to produce human stem cells which could in turn be used to create human tissue or organs, or to repair damaged organs. More, a report on the ‘justification of human cloning’ by Debashis Singh (2004) quoting Dr Wilmut says, “Human cloning promises such great benefits that it would be immoral not to do it”. He goes on to argue that cloning is crucial in the prevention of a hereditary, genetic diseases. Families who know that they place their child of danger of gaining a hereditary disease could screen an embryo, once generated through the process of vitro fertilisation, and take stem cells from it. These stem cells could then be “corrected” if there is a presence of an abnormality and placed into the womb of the mother. For, this allows parents the ability to give their child a higher quality of life, instead of placing them at a disadvantage. So, while the research of the Chinese team may be called out for being unethical, their work has the chance to aid many people – either through the testing of cures on a population of monkeys, or the manufacturing of humans to produce stem cells. This may mean the end of the line for the research team.

Evaluation

Personally, while I do believe the ethics of the work may need serious consideration from the government and legal system, this breakthrough may be one of the largest, and most important, scientific breakthroughs in the field of biology in recent memory. This breakthrough completely eclipses the cloning of Dolly the sheep, due to the ramifications that it holds on both society and biomedicine. Scientists have clearly been enticed by the potential medical successes it could produce, as they continually attempted to clone monkeys (which was impossible for over two decades) despite the cost of US$50,000 for each macaque. Though, I believe this cost to be completely justified; if the cloning is not to be banned. As mentioned before, the breakthrough can potentially save millions of human lives; testing of cures can occur on an identical population of primates, babies can be saved from obtaining hereditary diseases and more accurate live diseases models can be produced. Further, we finally have the opportunity to manufacture human life. While nobody should play the role of God, this signifies just how large and important a breakthrough this truly is. So, I believe that this discovery is extremely important due to the large level of difficulty scientists have experienced in their attempts and now has been overcome (signifying a large expansion upon our knowledge), and because of the impacts it can potentially have on the biomedical field.