Biotechnology
Table of Contents
Biotechnology refers to a way of manipulating living organisms to provide desirable products for human use. The term was coined by Karl Ereky.
UN Convention on Biological Diversity defines biotechnology as any technological application that uses a biological system, a living organism or derivatives thereof to make a modified product or process for a specific use.
1 Introduction
1.1 Milestones in Biotechnology in India
| 1978 | First biotechnology company Biocon established. |
| 1982 | National Biotechnology Board formed |
| 1986 | Department of Biotechnology created under Ministry of Science & Technology |
| 1997 | Shantha Biotech launched first recombinant vaccine – a Hepatitis B vaccine |
| 2002 | Genetic Engineering Approval Committee (GEAC) approved Bt cotton. |
1.2 Orgasations related to Biotechnology
| National Dairy Research Institute | Karnal |
| Central Food & Technology Research Institute | Mysore |
| Central Drug Research Institute | Lucknow |
| Centre for Cellular and Molecular Biology | Hyderabad |
| National Institute of Nutrition | Hyderabad |
2 Recombinant DNA Technology
Recombinant DNA Technology (RDT) is the umbrella term that encompasses all experimental protocols by which bits of DNA from one source is stably integrated into another DNA destination. Such transfer can take place between any two kinds of species (i.e. across any taxonomic distance) be they bacteria, fungi, plants or animals.
Stanley Cohen and Herbert Boyer were pioneers of this technology.
Two enzymes find application in RDT:
- Restriction endonuclease – to cut DNA at specific points.
- DNA ligase – to join two segments of DNA
3 Applications of RDT
3.1 Agriculture
- for developing GM plants which yield more while consuming less resources and in less time in order to improve food security.
3.2 Health
- development of safe, cost-effective vaccines
- manufacturing important proteins such as insulin, interferone (destroys viruses)
- production of specific enzymes like those that help in dissolving a blood clot
3.3 Industry
- production of different acids and alcohols, e.g. lactic acid
- mass production of vitamins, antibiotics, steroids, etc.
3.4 Environment
- GM bacteria to clear oil spills by digesting hydrocarbons
- Bioindicator organisms that are sensitive to environmental pollution
3.5 Bioremediation
- removal of harmful and toxic elements from environment
- conversion of biodegradabke wastes into bigoas
4 Transgenic Plants
These are genetically engineered plants whose chromesomes are incorporated with foreign genes (i.e. foreign DNA) from another species.
4.1 Applications
- To create disease resistant varieties.
- To create more tolerance towards adverse environment conditions
- Increase shelf-life of fruits and vegetables
- Modification of flower colour
- Produce pharmaceutically important compounds like hormones, ezymes, etc.
4.2 Bt Crops
Crops that are genetically engineered and carry gene from a species of bacteria called Bt (Bacillus thuringienesis). The bacteria produces a protein that is toxic towards pests but non-toxic towards human beings and other mammals. Crops containing Bt gene are able to produce this toxin and ensure protection for themselves. e.g. Bt cotton, Bt brinjal, Bt mustard, Bt corn, etc.
Bt has also been used by WHO to fight mosquitoes. It has also been used in organic farming.
4.2.1 Benefits of Bt crops
- Better quality
- Higher nutrition
- Inexpensive foods
- Greater shelf life
- Medicinal benefits (edible vaccines)
- Potentially better for environment (as decresae in pesticide use)
4.2.2 Risks
- pesticide-resistance insects may evolve
- Tendency to produce allergic reactions
- antibiotic resistance may develop
- crop contamination – plants bioengineered for pharmaceutical purposes may contaminate food crops
- possible monopolisation of world food market by MNCs that control distribution of GM seeds
- New GM organisms could be patented which has ethical concerns – treating life as commercial property
- using genes from animals in plants can produce ethical/religious concerns
- without proper and long-term testing, the effects of GM foods cannot be ascertained properly.
5 Gene Therapy
Experimental branch of medicine that incorporates techniques of genetic engineering to correct inherited disorders.
Dr. W. French Anderson is often called the father of gene therapy.
In gene therapy the flawed gene is identified and copies of its normal version are produced in lab by cloning. The suitable host cells are selected from patient's body and genetic engineering is used to transfer copies of the normal version of the gene into it.
It is used in correction of genetic disorders like haemophilia and colour blindness.
5.1 Cloning
A clone refers to a number of identical genes, cells, or organisms all derived from a common ancestor.
The process of producing genetically similar genes, cells or organisms from a common ancestor is called cloning.
Clones of bacteria, protozoa and plants can be easily obtained by asexual or vegetative reproduction, but cloning of animals is possible by chemically removing the nucleus of some parent cell and then transferring them into key nucleated eggs. The egg is activated by an electric impulse it begins the dividing and developing process.
5.1.1 Types of clones
- Gene cloning
- Cell cloning
- Organism cloning
Ian Wilmut & Others in 1997 produced the world's first cloned mammal – a sheep called Dolly – at Roslin Institute, Edinburgh.
5.1.2 Benefits of Cloning
- cloning for organ transplant
- improving livestock pedigree (superior breeds)
- improve population of endangered species can be increased, e.g. Hangul (Kashmiri Stag)
5.2 Examples of Cloned Animals
National Dairy Research Institute, Karnal has produced several cloned animals over the years.
| Name | Animal | Significance, if any |
|---|---|---|
| Garima | Buffalo | |
| Samrupra | Water buffalo | |
| Noori | Pashmina goat | |
| Swaran | Buffalo | male |
| Purnima | Buffalo | female |
| Rajat | Buffalo | male |
| Lalima | Buffalo | female |
| Karishma | Buffalo | daughter of Garima, world's first cloned baby |
| Deepasha | Wild water buffalo | state animal of Chhatisgarh |
6 Stem Cells
They are biological cells found in all multicellular organisms that can divide and differentiate into diverse specialised cell types and can self-renew to produce more stem cells.
6.1 Unique properties
- self-renewal: capable of dividing and renewing themselves for long periods
- unspecialised: does not have any tissue-specific structures that allow it to perform specialised functions
- potency: give rise to specialised cells, that process is called differentiation
6.2 Some terms
- totipotent: ability to differentiate into all possible cell types. (not found practically yet)
- pluripotent: ability to differentiate into almost all types of cells except placenta
- multipotent: ability to differentiate into a closely-related family of cells
- unipotent: ability to differentiate into cells of their own type only
6.3 Types of Stem Cells
- embryonic:
- derived from few-day old embryos
- pluripotent
- difficult to manipulate
- ethically contentious (embryo is destroyed in obtaining these cells)
- foetal stem cells:
- from aborted human foetuses
- limited availability
- multipotent
- ethically contentious
- adult:
- found in all humans
- form a limited number of cell types
6.4 Applications
- in drug delivery
- bone grafting
- arthiritis treatment
- helping body regrow tissue and cartilege
- can be engineered into HIV-fighting cells
6.5 Controversy
- debate centered on research involving the creation, usage and destruction of human embryo.