What do You Understand by Recombinant DNA Technology?

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What do You Understand by Recombinant DNA Technology?

Discuss the Moral, Ethical, Social, Economic and Environmental Issues Associated with the Technology, giving your views.

There are two essential substances found inside bacterial cells required before the process can begin. Present in the cytoplasm of a bacterial cell are a number of small circular pieces of DNA known as plasmids. Also present within the bacterial cell are restriction enzymes which cut DNA molecules at specific sites. By selecting the correct restriction enzyme, DNA molecules from different organisms can be cut at predictable sites to extract specific genes from lengths of DNA.

The first task in the process is to isolate the required gene. This can be done in three different ways; working backwards from the protein, using messenger RNA, or using DNA probes. Once the gene has been isolated, the next step is to cut the gene from its DNA chain. This is done using the restriction enzymes (restriction endonucleases). Now we have the required gene the next stage is to insert it into a vector which will be used to produce the required protein. This is where the plasmids described earlier come in (this could also be done using a virus as a vector). The plasmid is cut using the same restriction enzyme as was used to cut the gene out. In a process called ligation (controlled by the ligase enzyme) the ends of the gene and those of the plasmid join together. The new molecule contains genes from the plasmid and from another organism and is thus called recombinant DNA. This DNA is then introduced into the host cell and, using antibiotics the cells containing the recombinant DNA are selected. The genes which have been spliced into the vector continue to produce the same protein as they did in their original cells. The vectors then multiply and produce many genetically identical daughter cells which also produce the required protein. There are many different methods of genetic engineering, but the outcome is the same, DNA from one species is inserted into a different species and made to produce its normal proteins.

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Firstly I will consider the moral and ethical issues. It is hard to find any moral objection to the use of this technology in the treatment of diseases and improving food production. However, developing new therapeutic techniques may involve testing on animals. A laboratory animal’s genes may be altered so that it suffers from a human genetic disease, and then they could be used to try out a new gene therapy which could be beneficial to humans. Another ethical problem is the possibility of introducing favourable characteristics into human zygotes and thus creating “designer babies”. However, at present it ...

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