What is Genetic Engineering?

Genetic Engineering, also known as Genetic Modification, is the process of altering the DNA in an organism’s genome. This could mean extracting DNA from another organism’s genome and combining it with the DNA of that individual organism. Other ways of altering DNA includes changing one base pair (A-T or G-C) in the DNA, introducing an additional copy of a gene or deleting a whole region of DNA. Genetic Engineering is usually done to enhance or modify certain characteristics of an individual organism.

To understand Genetic Engineering, we must first understand how DNA works.

Double helix structure of DNA

Like how there is recipe for cookies, we have the recipe for life which is known as DNA (deoxyribonucleic acid). DNA is a double stranded molecule, made up of subunits called nucleotides. Each nucleotide contains a deoxyribose sugar, a phosphate group and one of the four nitrogenous base: Adenine (A), Guanine (G), Cytosine (C) and Thymine (T). The bases are paired up with their complementary bases, A with T and G with C, via hydrogen bonding. How these bases are sequenced will spell out different instructions for the cells to make proteins.

 

5 Steps of Genetic Engineering (Agriculture application)

Transformation of plant cells.

DNA Extraction

DNA is extracted from the desired organism containing gene of interest by undergoing a series of steps.

Gene Cloning

A small portion of the DNA which contains the gene of interest is isolated and made thousand copies of it.

Gene Design

Using enzymes – restriction endonucleases (molecular scissors) and DNA ligase (glue), certain parts of the gene is being cut away and replaced with the desired gene.

Transformation (Gene Insertion)

The new gene is then inserted into a cell, followed by multiplication of the cell. For agriculture applications, tissue culture is used to propagate masses of undifferentiated plant cells called callus. This is due to the fact that plants contains millions of cells. Therefore, the new gene is inserted into some of those cells via different techniques such as gene gun, agrobacterium or electroporation. Ultimately, the aim is to transport the new gene and deliver them into the nucleus of a cell without killing it. The transformed plant cells are then regenerated into transgenic plants.

Backcross Breeding

The transgenic plants are crossed with elite breeding lines using traditional plant breeding methods to combine the desire traits of elite parents and the transgene into a single line.

References

AgBiosafety at UNL – Biotech Basic The Preocess of Plant Genetic Engineering. (2017). Agbiosafety.unl.edu. Retrieved 21 March 2017, from http://agbiosafety.unl.edu/education/summary.htm

Genome Research Limit,. (2016). double helix structure of DNA. Retrieved from http://www.yourgenome.org/sites/default/files/illustrations/diagram/dna_double_helix_yourgenome.png

Transformation of plant cells. Retrieved from https://ib-biology2010-12.wikispaces.com/file/view/transformation_in_plants.gif/327852588/447×376/transformation_in_plants.gif

UNL’s AgBiosafety for Educators. (2017). Agbiosafety.unl.edu. Retrieved 29 February 2017, from http://agbiosafety.unl.edu/basic_genetics.shtml

What is genetic engineering?. (2017). Yourgenome.org. Retrieved 17 February 2017, from http://www.yourgenome.org/facts/what-is-genetic-engineering