Insertion of foreign genes and Cloning

Genetic engineering requires modern and advance technology thus it is going to widely used and dependent in the future when science has been further enhanced. It has already been explore in the last century and in the initial stages of implementation and usage in the twenty first century, mostly in research and development sector and science. There are four different aspects of genetic engineering which is cloning, insertion of foreign genes in an organisms mainly animals, genetically modified food and for research in the medical sector.

Firstly, the insertion of foreign gene(s) into animals’ genome is known as transgenic. These animals created from transgenesis are useful as disease models, animals which are genetically manipulated to display disease symptoms so that effective treatment can be studied.

As a result, transgenic animals are created: transgenic pigs that will serve as a source of transplanted human organs for humans, transgenic cattle, such as the first transgenic cow, Rosie in 1997, to produce milk enriched with particular human proteins to help in some treatments of diseases, and the list goes on. To date, there are three basic methods of producing transgenic animals: DNA microinjection, Retrovirus-mediated gene transfer and embryonic stem cell-mediated gene transfer. However, the success rate of producing transgenic animals individually by these methods is very low and thus, it is probably more efficient to use cloning techniques to increase their numbers.

Transgenic process is preferred to over selective breeding, as the development of traits in animals is made possible in a shorter time and with more precision, resulting in the breeding of large number of offspring of a certain species and the increase in yield for livestock farmers, especially to meet the rising demands of food consumption.

Moreover, the insertion of foreign gene into animals’ genome can also be used in gene therapy, where it can help treat certain diseases or slow down the progression of the disease such as the lung disease, cystic fibrosis. In cystic fibrosis, as the bronchial tubes produce mucus that blocks up the respiratory system, making it difficult to breathe, this disease can be treated by replacing defective genes in damaged airway cells with healthy genes, with the use of vectors.

However, as there are two sides to the coin, inserting foreign gene(s) into animals will also give rise to disadvantages. Nature is an extremely complex inter-related food web consisting of many species, resulting the loss of genetic diversity should the favourable traits inserted be the same. Moreover, insertion of the same favourable genes may lead to the whole species being wiped out if the genes inserted are not resistant to an unknown potent virus, which may be introduced into the environment. Introducing genetically modified genes may have an irreversible effect with consequences yet unknown. Also, the consumption of such animals may pose unknown health and medical risks to the consumers. In gene therapy, if a gene inserted in the body cells find its way into the ova or sperms, and mutates, it may affect the offspring of the patient.

In conclusion, transgenesis shall be our last resort if the alternative measures to meet the demands of the population have been exhausted and were not successful.

Secondly, cloning brings the possibility to clone organs that could be use for organ transplant thus donors are not needed. Moreover, cloning technology enables scientist and researchers to find out more about disease causing genes and how to cure them with the different types of cloning technology like DNA cloning, reproductive cloning and therapeutic cloning. However they do not realize the social implications on the cloned individual as well to the society. In addition to those implications is the difficulty to clone an organism as the scientific knowledge to know what their initial stages of development are and the technology used still requires improvements. The most well known cloned animal is Dolly the sheep, a successful experiment but most do not realise that among the 276 experiments conducted only Dolly came out a success. This indicates that cloning technology is still pretty unreliable and not yet dependable in the present. However the negative impacts are far-reaching with long-term effects. One of the risks are that it interferes with evolution as it removes independent assortment process as well as cross-linking that is carried out to form gametes with different genetic material than their parents. As a result, it could distort generation lines and family relationships, limit genetic differentiation that allows us to adapt to changes in our environment and ensures human life is unique. Ethical issues arise as ‘spare parts’ for their original counterpart instead of as unique individuals and the process of cloning is unnatural, thus they are taken seriously by the public especially by religious body.

Furthermore, reproductive cloning is expensive and highly inefficient evident from the low success rates as well ascomplications with the clone state of health. Cloned animals tend to have more compromised immune function, higher rates of infection, tumour growth and other disorders. Moreover, they have been known to die mysteriously from the extensive research conducted and the sudden death of Dolly as an example. Therefore this technology still requires further development before it is used in large scale and the social issues are not as severe once the public accepts clones into their society.

By: Tan Wan Ting and Nur Afiqah Bte Dzulkifley 10S01

1 comment:

K Loh said...

What caught my attention about this article was subject on insertion of foreign genes and cloning. The technology advanced enough to manipulate our gene structure was made available in the last century, making this feat recent. Today, as students we learn about the technicality of cross breeding and insertion of gene but to see or rather hear of it being done by scientists is a totally new and exciting thing.

The article showed the pros and cons of gene transfusion such as using it to treat certain diseases and the disruption of the natural balance of the world. I think that as with all sort of issue, there will always be pros and cons but to maximize the pros is something that we should aim for in this area of research. The fact that scientists are able to extract DNA from a species and inject it into another has opened new doors for other researches to improve our lives on earth. It might not be accepted by some but then again, if everyone would be accepting, there wouldn’t be war and violence. However, while I think that injecting foreign genes is beneficial to us, cloning is an issue which I think need to be looked at seriously. By cloning, I shall interpret it as mass manufacturing of identical identity from the original thing. Be it human or animal or plants, evolution occurs when there is change in our ability to adapt to the current environment. Cloning takes out the change factor, dimming our evolution prospect. Hence, it might be detriment to our society if we practice cloning

On the bright side, transfusion of genes looks promising and further study into might produce results that will help us in the future. In Singapore, due to a lack of both natural resources and space, we need to produce the best goods using technology without wasting space. Hence, this method might be useful for us to be self sustainable in the future. From the article, I quote “Transgenic process is preferred to over selective breeding, as the development of traits in animals is made possible in a shorter time and with more precision, resulting in the breeding of large number of offspring of a certain species and the increase in yield for livestock farmers, especially to meet the rising demands of food consumption”. This shows that the process can shorten breeding time as well as double the yield, an ideal situation for a small country with a large population like Singapore. As such, we should learn to accept some parts of it in our lives and expand our research on it to being more benefits to our daily lives.

By Ang Hong 10S01