Biotechnological applications

1. BIOTECHNOLOGICAL
APPLICATIONS
(AGRICULTURE)

2. Genetically modified organisms (GMO) –
Plants,Bacteria,Fungi & animals whose
genes have been altered by manipulation.
Genetic modifications has-
- Made crops more tolerant to cold,- Made crops more tolerant to cold,
drought,salt,heat.
- Pest-resistant crops.
- Reduce post-harvest losses.
- Increased efficiency of mineral usage.
- Increased nutritional value of food eg.
Vitamin A enriched rice.

3. Bt-Cotton
Bacillus thuringiensisBacillus thuringiensis produce crystals of proteins thatproduce crystals of proteins that
kill certain insects for eg.kill certain insects for eg. LepidopteransLepidopterans (tobacco(tobacco
budworm, armyworm),budworm, armyworm),ColeopteransColeopterans (Beetles) &(Beetles) &
dipterans flies,mosquitoes).dipterans flies,mosquitoes).
Why does this toxin not kill BacillusWhy does this toxin not kill Bacillus??
-- BtBt--toxin protein exist as inactivetoxin protein exist as inactive protoxinsprotoxins & it& it-- BtBt--toxin protein exist as inactivetoxin protein exist as inactive protoxinsprotoxins & it& it
becomes active due to alkaline pH of gut whichbecomes active due to alkaline pH of gut which
dissolve the crystals.dissolve the crystals.
-- Activated toxin create pores in midgut epithelial cellsActivated toxin create pores in midgut epithelial cells
causing swelling & lysis and death of insect.causing swelling & lysis and death of insect.
-- Toxin is coded by a geneToxin is coded by a gene crycry which are of a no. ofwhich are of a no. of
types like cryIAc , cryIIAb control Cotton bollworms &types like cryIAc , cryIIAb control Cotton bollworms &
cryIAb controls corn borer.cryIAb controls corn borer.

4. Pest resistant plants
A nematode Meloidegyne incognitia infects roots of
tobacco plants causing huge loss of yield.
CONTROL-By RNA interference (RNAi)
RNAi involves silencing of specific mRNA
due to a complementary ds-RNA(doubledue to a complementary ds-RNA(double
stranded RNA) which binds & prevent
translation of m-RNA.
-Source of complementary ds-RNA are-
1.An infection by virus with RNA genome
2.TRANSPOSONS- mobile genetic elements which
replicate through RNA intermediates.

5. Applications in medicine
GENETICALLY ENGINEERED INSULIN
Insulin consists of two short polypeptide chains-Chain
A & Chain B linked together by disulphide bridges.
In mammals Insulin is synthesized as a pro-hormone
containing an extra stretch of C-peptide. At
maturation of Insulin C-peptide is removed.maturation of Insulin C-peptide is removed.
In 1983 ELI LILLY COMPANY (USA) prepared two DNA
sequences (chain A & chain B) & produced them
separately using plasmid of E.coli and combine them
by disulphide bonds to form human insulin.

7. Gene therapy
It is a correction of a gene defect that has been
diagnosed in a child or embryo through delivery of a
normal gene.
First Gene therapy-1990-A 4 year old girl with ADA
(Adenosine deaminase) deficiency. ADA is essential
for functioning of immune system.for functioning of immune system.
Lymphocytes from blood grown in a culture –a
functional ADA-cDNA introduced & returned to the
patient. (not a permanent cure as Lymphocytes die
after some time).
If Gene producing ADA is isolated from bone marrow
cells is introduced in cells at early embryonic stages.
It could be a permanent cure.

8. Molecular Diagnosis
PCR
(Polymerase chain reaction)
-A very low concentration of a bacteria or Virus can be
detected by amplification of their DNA/RNA by PCR.
-PCR is also used to detect mutations in genes in suspected
Cancer patients.
AUTORADIOGRAPHYAUTORADIOGRAPHY
-Single stranded DNA or RNA is tagged with a radioactive
molecule (PROBE).
-It is hybridised to its complementary DNA in a clone of cells.
-Clone having mutated gene will not appear on the
photographic film as probe do not have complementarity
with mutated gene.
ELISA
-It is based on the principle of antigen-antibody interaction.

9. TRANSGENIC ANIMALS
Animals whose DNA is manipulated to possess & express an extra
(foreign) gene.
Reasons of production
1.To study how genes are regulated - Eg.-Study of complex factors
involved in growth such as insulin like growth factor by
introducing genes from other species.
2.To study how genes contribute to the development of disease –
Eg.- Transgenic models exist for human diseases like Cancer,Eg.- Transgenic models exist for human diseases like Cancer,
Cystic fibrosis, Rheumatoid Arthritis, Alzheimer’s.
3.Biological products –Eg-(i) Human protein (α-1-antitrypsin)
used to treat Emphysema. (ii)-First transgenic cow Rosie produced
human protein enriched milk (human alpha- lactalbumin) 2.4
gms/litre.
4.Vaccine safety – Transgenic mice are used to test the safety of
the Polio vaccine.
5.Chemical safety testing – Transgenic animals are made that
carry genes which make them more sensitive to toxic substances.

10. ETHICAL ISSUES
-In India GEAC (Genetic Engineering approval
Committee) make decisions regarding validity of GM
research and the safety of introducing GM-organisms
for public services.
-Problems of Patents –
1.An American company got patent rights on Basmati
rice in 1997 as a new variety. This new variety was
1.An American company got patent rights on Basmati
rice in 1997 as a new variety. This new variety was
actually derived from Indian farmer’s varieties.
2.Several attempts are made to patent Turmeric , Neem.
-BIOPIRACY –
It is the use of bio-resources by multinational companies
and other organizations without proper authorisation
from the countries & people concerned without
compensatory payments.