Genetically Modified Organisms: Overview, Advantages, Examples

Have you heard of Bt-cotton or Bt-brinjal? Are these naturally obtained plant products or man-made? These are represented or referred to as Genetically Modified Organisms that involve transgenic plants and animals. These are modified, and the modifications usually involve specific intervention in the genotype of the organism.

In this article, we will discuss about GMOs definitions, examples, advantages and much more. Let us dive into the article to know more about Genetically Modified Organisms.

What are Genetically Modified Organisms?

Genetically modified organisms (GMOs) are organisms in which the genetic material (DNA) has been altered or artificially manipulated in a way that does not occur naturally by mating or natural recombination.
The genetic modification of organisms or ‘genetic engineering’ involves technology such as ‘gene technology’ or ‘recombinant DNA technology’, and the resulting organism is said to be ‘genetically modified’, ‘genetically engineered’ or ‘transgenic’.
The term “transgenic” refers to the transfer of genetic material from one species to another. A transgenic organism is an organism in which DNA is manipulated to possess and express an extra (foreign) gene from a different species.

Fig: Genetically Modified Organisms

What are Genetically Modified Plants?

i. Crops that have their DNA altered through genetic engineering techniques are known as genetically modified crops. These are also known as transgenic crops.
ii. The main purposes of GM crops generally include resistance to certain pests, diseases, or environmental conditions, or resistance to chemical treatments (e.g. resistance to a herbicide).
iii. A plasmid from the soil bacteria Agrobacterium tumefaciens is commonly used to introduce additional genes into plant cells. This is the plasmid Ti (tumour inducing plasmid). It got its name because it causes tumours in broadleaf plants in nature.
iv. Researchers have removed the tumour-causing characteristics of Ti plasmid while maintaining its capacity to transfer DNA into plant cells in order to use it as a vector. 
v. As a result, Agrobacterium strains with tumour-forming genes are created for genetic engineering objectives. 
vi. Plant cells can still be infected by these altered bacteria. T-DNA refers to the portion of the Ti plasmid that is transferred into plant cell DNA.
vii. This T-DNA with the desired DNA spliced into it is introduced into the host plant’s chromosomes, where it creates copies of itself by randomly migrating from one chromosomal location to another. 
viii. After that, the plant cells are cultivated and encouraged to proliferate and differentiate into plantlets. 
ix. After being transplanted into the soil, the plantlets mature into full plants that carry the foreign gene, which is expressed by the new plant.

Examples of GMO Crops

The examples of GMO Crops are listed below:

Bt Crops

Bt Crops are transgenic plants that generate the same toxin as the Bacillus thuringiensis bacteria in the plant cell, protecting the plants against pests. The Bt toxin gene was cloned from bacteria and produced in plants to offer insect resistance without the use of pesticides, resulting in a bio-pesticide.
Example: Bt-cotton
i. Some strains of Bacillus thuringiensis produce protein crystals in a specific phase of their growth.
ii. The crystals consist of a toxic insecticidal protein that kills specific insects such as lepidopterans, coleopterans (beetles), and dipterans (flies, mosquitoes).
iii. However, the toxin does not kill the Bacillus as the Bt-toxin protein exists as inactive proteins. Still, once the insect ingests the inactive toxin, it is then modified into an active form of toxin owing to the alkaline pH of the gut, which ultimately solubilizes the crystals.
iv. The activated toxin binds to the surface of midgut epithelial cells and creates pores that lead to cell swelling and lysis, resulting in the death of the insect.
v. The toxin is coded by a gene denoted as ‘cry.’
vi. There are multiple genes functioning against the insects. For example, the proteins encoded by the genes cryIAc and cryIIAb control the cotton bollworms, whereas cryIAb controls corn borer.
vii. Specific Bt-toxin genes are isolated from Bacillus thuringiensis depending upon the crop and the targeted pest, which is then incorporated into a number of crop plants.

Fig: Bt-cotton

Golden Rice

Golden Rice is also known as vitamin A enriched rice.
To produce vitamin A enriched rice, two genes from daffodil and another one from the bacterium Erwinia uredovora were inserted into the rice genome. These three genes produce the enzymes essential to produce provitamin A. When golden rice is ingested, the human body splits the provitamin A for making vitamin A. As this newly invented rice is in light yellowish colour, it is named Golden Rice.

Fig: Golden Rice

Advantages and Disadvantages of GM Crops

The advantages and disadvantages of GM crops are given below:

Genetically Modified Animals

Transgenic animals are animals whose DNA has been altered to allow them to possess and express a foreign gene. Transgenic rats, rabbits, pigs, sheep and other animals are examples.
The gene of interest is genetically changed in the embryo of these animals, and the resultant animal produces more milk, meat, and prevents illnesses etc.
Some of the common reasons for the production of transgenic animals:
I. Study of disease: Most animals that are GMOs are produced for use in laboratory research. These are specially made to serve as models to study the function of specific genes and, typically, how the genes are related to health and disease.
II. Transgenic Animals in Agriculture: Some GMO animals, however, produced for human consumption have the opportunity to significantly improve human health, enhance nutrition, protect the environment, increase animal welfare, and decrease livestock disease. For example, Salmon fish has been genetically engineered to produce growth hormones and can be sold as a full-size fish after \(18\) months instead of \(3\) years.
III. Biological products: Transgenic animals are produced to create useful biological products that can be created by the introduction of the portion of DNA (or genes) which codes for a particular product such as Rosie, the transgenic cow produced human protein-enriched milk. 
IV. Safety of Vaccines:  Transgenic mice have been developed for use in testing the safety of vaccines before they are used on humans, and if found reliable, they could replace the use of monkeys. These genetically modified animals are specifically designed to allow the study of how genes are regulated and how they affect the normal functions of the body and its development.

GMOs in Medicine

I. GMOs are used to produce insulin, growth hormones, various antibodies and many medicines and vaccines that help treat or prevent diseases.
II. Development of vaccines by inserting specific genes from disease-causing viruses and/or bacteria into harmless viruses. These modified viruses potentially allow the body to develop immunity to the original, infectious virus or bacterium.
III. Insulin used for diabetes was earlier extracted from pancreas slaughtered cattle and pigs, but some patients developed allergies due to it. Bacterial cells can be genetically modified so that they have the gene for producing human insulin, and the first genetically engineered, synthetic “human” insulin was produced in \(1978\) using E. coli bacteria.

Summary

Genetically Modified Organisms are the organisms in which the genetic material, usually DNA, has been altered in such a way as to get the required quality. Through this article, we understood how disease-resistant crops are being produced against pests and how they are useful in the development of agricultural yield. Many transgenic animals are created to help us better understand how genes contribute to disease development. Despite the benefits of genetically modified foods, there are still hazards to be aware of, and we must take precautions. Many individuals believe that genetic engineering is the way of the future and that we cannot afford to ignore a technology with so many potential benefits.

FAQs on Genetically Modified Organisms

Q.1. What was the first genetically modified animal?
Ans: Rudolf Jaenisch generated the first genetically engineered mammal, a mouse. 

Q.2. What are 5 genetically modified organisms?
Ans: The five genetically modified organisms are Corn, Soybean, Cotton, Potato and Dolly.

Q.3. What are the negative effects of GMOs?
Ans: The negative effects of GMOs are allergic reactions, toxicity, Antibiotic Resistance, Loss of Nutrition, cancers, etc.

Q.4. Why are genetically modified organisms important?
Ans:  The genetically modified organisms are important because of the following reasons:
I. Increased crop yields
II. Lower food and drug production costs
III. Reduced the usage of pesticides
IV. Improved nutrient composition and food quality
V. Pest and disease resistance
VI. Greater food security
VII. Medical benefits to the world’s growing population.

Q.5. Does Golden Rice help with vitamin A?
Ans: Golden rice is a genetically engineered grain designed to boost vitamin A levels in the diet. A vitamin A inadequacy can cause blindness and death at a young age. The human body divides provitamin A to make vitamin A when golden rice is consumed.

We hope this detailed article on Genetically Modified Organisms helps you in your preparation. If you get stuck do let us know in the comments section below and we will get back to you at the earliest.