Genetic engineering refers to the use of biotechnology to directly manipulate an organism’s DNA. It encompasses a multitude of techniques for altering the genetic material of cells. It includes a gene transfer inside and between different species, in order to create better or novel organisms. New DNA is created by extracting and duplicating the genetic material of interest using recombinant DNA technologies or by synthesising it chemically. 

History of genetic engineering 

Originally, the term genetic engineering referred to a variety of approaches for altering or manipulating organisms via heredity and reproduction. As a result, the term encompassed both artificial selection and all biological interventions, including artificial insemination, in vitro fertilisation, cloning, and gene manipulation. 

However, by the late twentieth century, the word had come to apply more explicitly to recombinant DNA technology (or gene cloning), in which DNA molecules from two or more sources are merged either within cells or in vitro and then placed into host species where they can multiply.

The discovery of restriction enzymes by Swiss scientist Werner Arber in 1968 paved the way for recombinant DNA technology. The very next year, American microbiologist Hamilton O. Smith isolated type II restriction enzymes, which were shown to be necessary for genetic engineering because of their capacity to cleave a specific location inside DNA (as opposed to type I restriction enzymes, which cleave DNA at random sites).

What are genetic engineering techniques?

Most recombinant DNA technologies require the insertion of foreign genes into the plasmids of typical laboratory bacteria strains. 

• Plasmids are tiny DNA rings that are not part of a bacterium’s chromosome (the organism’s major reservoir of genetic information). 
• They are capable of protein synthesis and, like chromosomal DNA, are replicated and passed on to the bacterium’s descendants. 
• Also, if the inserted gene is functional the transformed bacteria will create the protein that the foreign DNA specifies.

Gene editing was the focus of the wave of genetic engineering techniques that arose in the early twenty-first century. 

• Researchers may tailor a living organism’s genetic sequence by making exact changes to its DNA using gene editing.
• Genome editing is based on the CRISPR-Cas9 technology. 
• Gene editing offers a wide range of uses, including crop plant and livestock genetic alteration, as well as laboratory model organisms.

The ability of gene editing to fix genetic mistakes linked to disease in animals suggests that it could be used in human gene therapy. 

• Gene therapy involves inserting a healthy gene into another person’s genome to correct a mutation that could cause a hereditary disease. 
• When a normal gene is put into a mutant nucleus, it will most likely integrate into a chromosomal position other than the defective allele. 
• While this may correct the mutation, if the normal gene integrates into another functional gene, a new mutation may arise. 
• There’s a chance that if the normal gene replaces the mutant allele, the transformed cells will multiply and create enough normal gene product for the entire body to be restored to its pre-diseased state.

Applications of genetic engineering 

Many theoretical and practical aspects of gene function and organisation are in use today thanks to genetic engineering. 

• Bacteria capable of manufacturing human insulin, human growth hormone, alpha interferon, a hepatitis B vaccine, and other therapeutically important compounds have been developed using recombinant DNA technology. 
• Plants can be genetically modified to fix nitrogen, and genetic illnesses can be treated by replacing faulty genes with ones that work normally. 
• Toxin-producing genes have been inserted into various plant species, including corn and cotton. 
• Crop plants have also been inoculated with bacterial genes that give herbicide resistance. 
• Other attempts at plant genetic engineering have tried to improve the plant’s nutritional value.

Challenges of genetic engineering

The concept of genetic engineering is debatable in terms of bioethics, with proponents and detractors arguing about the right to alter or mould nature to suit our purposes. 

• The development of genetically altered creatures may have unintended consequences and cause undesirable outcomes. 
• The introduction of a genetically modified creature into one environment for the desired outcome may cause biodiversity to be distorted.
• Genetically modified crops can have negative health consequences.

Conclusion

Multiple techniques can be used to carry out genetic engineering. Before a genetically modified organism (GMO) is generated, a series of stages must be completed. Before they may insert, edit, or delete a gene, genetic engineers must first decide which gene they want to implant, modify, or delete. It can be used in multiple ways for advancing agriculture and various other fields but must be carefully used. The concept of genetic engineering is debatable in terms of bioethics, with proponents and detractors arguing about the right to alter or mould nature to suit our purposes. The development of genetically altered creatures may have unintended consequences and cause undesirable outcomes.