Question

Some scientists are concerned that genetic engineering allows humans to tamper with evolution. Discuss some of the advantages and disadvantages of recombinant DNA technology.

Answer 1

Recombinant DNA technology (r-DNA technology) or genetic engineering is a branch of biotechnology in where the products of living cells like restriction enzymes, DNA ligases and DNA molecules (e.g. plasmids) are used to construct the new DNA molecules which carry the new combination of genes.

Advantages of Recombinant DNA technology:

1. The r-DNA technology allows the identification and repair of mutated genes in most of the genetic diseases, such as cystic fibrosis, Sickle cell anemia, and Huntington’s disease are due to the mutations in the genes. By cloning the normal copies of mutated genes by r-DNA technology methods allow the replacement of mutated copies of these genes with the normal copies of the gene.
2. By identifying the differentially regulated genes in cancer cells it is possible to treat cancer. Modification of these differentially regulated genes of cancer cells by r-DNA technology allows us to stop the uncontrolled proliferation of the cancer cells in the body.
3. By using r-DNA technology it is possible to produce new vaccines which are more efficient than the vaccines produced by the traditional methods. The r-DNA technology produced two types of vaccines 1) subunit recombinant vaccines: which have the components of pathogenic organisms. E.g. Hepatitis B vaccine 2) attenuated recombinant vaccines: produced by the medication of genetic material of diseases causing organisms. E.g. V. cholera vaccine.
4. r-DNA technology methods promoted the generation of new plant varieties, which increased the crop production drastically. The transgenic plants produced by this method showing high resistance towards the insects (e.g. cowpea trypsin inhibitor expressing plants), herbicides (e.g. expression of EPSPS enzyme), bacteria, viruses and various environmental conditions (salt stress, oxidative stress).
5. Various metabolic diseases are treated by the use of products which are developed by the r-DNA technology methods. For example, Diabetes is a metabolic disease in which high sugar levels are observed and it is treated with the insulin, a peptide hormone. The recombinant insulin generated by the r-DNA technology methods is exactly similar to the human insulin and allow the diabetic patients to maintain their normal bold sugar levels in their body.

Disadvantages:

1. Production of genetically engineered products is very expensive and highly technically trained persons are required.
2. Introduction of new species which are produced by the r-DNA technology can eradicate the native species and which can have a drastic effect on ecological balance. The disturbance due to the newly introduced species responsible for the complete extinction of other native species from that geographical region.
3. The genetically produced normal genes have antibiotic resistance gene which acts as a marker gene. When such marker gene having normal genes introduced into cancer cells to treat cancer, the cancer cells develop resistance towards various disease-causing organisms.
4. The continuous exposure of proteins (that control the insects) produced by the genetically engineered insect-resistant plants can introduce mutations in the targeted insects and after few generations, the insects will develop resistance against these proteins and making them very difficult to control.
5. Ethical and health issues will be raised against the use of foods which are produced by the genetic engineering methods.