Genetic Engineering

13.1

Genetic Engineering

Introduction to Genetic Engineering

Genetic engineering is a gene manipulation technique to genetically modify an organism to form new gene combinations.
Organisms whether animals, plants or microorganisms produced through recombinant DNA technology are known as genetically modified organisms or genetically modified organisms (GMOs).
Genetic engineering involves the transfer of DNA segments from one organism to another through recombinant DNA technology.
By using techniques and procedures in recombinant DNA technology, biologists can reconstruct the DNA or genome (a complete set of DNA) of an organism.

Genetically Modified Organism (GMO)

Genetically modified organisms (GMOs) are organisms that contain recombinant DNA.
Through recombinant DNA technology, new combinations of genes are produced in an organism.
Organisms that contain recombinant DNA are known as transgenic organisms.
Example of enetically modified organisms (GMOs):
- Genetically modified cow produces milk which does not contain β-lactoglobulin, a type of protein that causes allergy among some children.
- Genetically modified goat possesses the human gene which codes for a blood clotting factor. This blood coagulation factor is found in the goat’s milk and can be purified and used to treat haemophilic patients.

Genetically Modified Food (GMF)

Recombinant DNA technology has successfully produced many crops (rice, oil palm, pineapple, corn and soybeans) as well as livestock (salmon, cattle and goats) that have the desired characteristics.
Genetically modified foods (GMF) have DNA from other plant or animal species.
Intake of GMF by humans is likely to have a variety of still unknown health implications.

Advantages and Disadvantages of GMF

Advantages of GMF

Overcome worldwide food shortage by producing high quality transgenic crops amd livestock.
Reduce cost of food production.
Increase nutritional value of crops.
Reduce problems of crops related to pests.
Reduce usage of pesticides.
Increase in production reduces price of food,thus increase food availabilty.

Disadvantages of GMF

Endangered natural species.
There is a slight possibility that the foreign gene in GMF may be transferred to humans,for example, antibiotic-resistance gene.
May have adverse effects on human health and genetic material.

Examples of GMF

Corn

A Bacillus thuringiensis gene is inserted into corn to increase its resistance against insect pest.

'Super Salmon'

'Super Salmon' is a genetically modified fish which is approved by the Food and Drug Administration (FDA) as a safe food for consumption in United States of America and Canada.
It is modified by inserting a growth hormone gene from a Chinook salmon into the genome of an Atlantic salmon.
Hence, a Super Salmon is created which grows at a faster rate and can be produced throughout the year.

Insulin

The hormone insulin plays an important role in controlling blood sugar levels.
In the past, insulin was extracted from the pancreas of cattle or pigs to treat patients with diabetes mellitus.
Now, insulin can be obtained from genetic engineering techniques and can be produced commercially for the use of diabetics
In addition to insulin, hepatitis B vaccine, blood clotting factors and growth hormone have been successfully genetically engineered.