Biotechnology and its Applications — Short Notes
Biotechnology has three main application areas: agriculture, medicine, and environmental management.
Biotechnological Applications in Agriculture
Three ways to enhance farming: agrochemical use, organic farming, genetically engineered crops.
GM (Genetically Modified) Plants
- Plants whose DNA has been altered by genetic engineering.
- Also called transgenic plants.
- Benefits:
- Resistance to abiotic stresses (cold, drought, salt).
- Reduced dependence on chemical pesticides.
- Reduced post-harvest losses.
- Increased efficiency of mineral usage.
- Enhanced nutritional value.
Bt Cotton
- Bacillus thuringiensis makes Cry proteins (Bt toxin) that kill certain insects.
- Bt toxin is inactive protoxin in bacterium; becomes active only in alkaline pH of insect gut → binds gut wall → kills insect.
- Bt gene isolated and introduced into cotton → Bt cotton — resistant to bollworms.
- Cry genes:
- cryIAc, cryIIAb — cotton bollworms.
- cryIAb — corn borer.
Pest-Resistant Plants (RNA Interference — RNAi)
- Nematode Meloidogyne incognita infests tobacco.
- Approach: introduce nematode-specific dsRNA into tobacco via Agrobacterium vector.
- Host produces siRNA that silences the parasite's mRNA → parasite cannot survive.
- Basis: RNA interference (RNAi) — post-transcriptional gene silencing by complementary dsRNA.
Biotechnological Applications in Medicine
Recombinant Insulin
- Diabetes is treated with insulin.
- Traditional source: cow/pig pancreas — caused allergic reactions.
- Human insulin: A (21 aa) and B (30 aa) chains joined by disulfide bridges.
- In humans, insulin is made as preproinsulin → proinsulin → mature insulin by removal of C-peptide.
- In 1983, Eli Lilly produced humulin using E. coli — synthesised A and B chains separately, then combined by disulfide bonds.
Gene Therapy
- Corrects a genetic defect by introducing a normal gene into cells.
- First successful gene therapy: 1990, SCID (Severe Combined Immunodeficiency) caused by ADA (adenosine deaminase) deficiency.
- ADA gene inserted into lymphocytes → returned to patient. Not permanent — must be repeated.
- Ideal cure: insert into bone marrow stem cells (permanent).
Molecular Diagnosis
- Diagnose diseases at DNA/RNA level, before symptoms appear.
- Tools: PCR, ELISA, DNA probes.
- Applications:
- PCR detects HIV, TB (mycobacterium), mutations in cancer.
- ELISA — detects antigens/antibodies (HIV testing).
Transgenic Animals
Animals with foreign genes.
- Uses:
- Study normal gene regulation & disease development.
- Biological products — human α-1 antitrypsin from transgenic sheep for emphysema.
- Vaccine safety — transgenic mice replace monkeys for polio vaccine testing.
- Chemical safety testing — toxicity in transgenic animals.
- First transgenic cow Rosie (1997) — produced human α-lactalbumin-enriched milk (2.4 g/L) — nutritionally more balanced for human babies.
Ethical Issues
- GEAC — Genetic Engineering Approval Committee (India) — reviews GMO safety and validity for public use.
Biopiracy
- Use of bio-resources by MNCs and organisations without authorisation or compensation to source countries.
- Rich nations tap the biodiversity of poor nations.
- Example: Turmeric, Basmati rice, Neem — patents granted (later revoked) in USA on traditional Indian knowledge.
- India has passed the Indian Patents Bill (Second Amendment) to prevent unauthorised exploitation.
Take-aways
- Genetic engineering has produced Bt cotton, RNAi tobacco, humulin insulin, gene therapy, transgenic animals.
- GEAC oversees GMO safety in India.
- Biopiracy is a major ethical issue — needs national laws to protect biodiversity.
Biotechnology and its Applications — Short Notes
Biotechnology has three main application areas: agriculture, medicine, and environmental management.
Biotechnological Applications in Agriculture
Three ways to enhance farming: agrochemical use, organic farming, genetically engineered crops.
GM (Genetically Modified) Plants
- Plants whose DNA has been altered by genetic engineering.
- Also called transgenic plants.
- Benefits:
- Resistance to abiotic stresses (cold, drought, salt).
- Reduced dependence on chemical pesticides.
- Reduced post-harvest losses.
- Increased efficiency of mineral usage.
- Enhanced nutritional value.
Bt Cotton
- Bacillus thuringiensis makes Cry proteins (Bt toxin) that kill certain insects.
- Bt toxin is inactive protoxin in bacterium; becomes active only in alkaline pH of insect gut → binds gut wall → kills insect.
- Bt gene isolated and introduced into cotton → Bt cotton — resistant to bollworms.
- Cry genes:
- cryIAc, cryIIAb — cotton bollworms.
- cryIAb — corn borer.
Pest-Resistant Plants (RNA Interference — RNAi)
- Nematode Meloidogyne incognita infests tobacco.
- Approach: introduce nematode-specific dsRNA into tobacco via Agrobacterium vector.
- Host produces siRNA that silences the parasite's mRNA → parasite cannot survive.
- Basis: RNA interference (RNAi) — post-transcriptional gene silencing by complementary dsRNA.
Biotechnological Applications in Medicine
Recombinant Insulin
- Diabetes is treated with insulin.
- Traditional source: cow/pig pancreas — caused allergic reactions.
- Human insulin: A (21 aa) and B (30 aa) chains joined by disulfide bridges.
- In humans, insulin is made as preproinsulin → proinsulin → mature insulin by removal of C-peptide.
- In 1983, Eli Lilly produced humulin using E. coli — synthesised A and B chains separately, then combined by disulfide bonds.
Gene Therapy
- Corrects a genetic defect by introducing a normal gene into cells.
- First successful gene therapy: 1990, SCID (Severe Combined Immunodeficiency) caused by ADA (adenosine deaminase) deficiency.
- ADA gene inserted into lymphocytes → returned to patient. Not permanent — must be repeated.
- Ideal cure: insert into bone marrow stem cells (permanent).
Molecular Diagnosis
- Diagnose diseases at DNA/RNA level, before symptoms appear.
- Tools: PCR, ELISA, DNA probes.
- Applications:
- PCR detects HIV, TB (mycobacterium), mutations in cancer.
- ELISA — detects antigens/antibodies (HIV testing).
Transgenic Animals
Animals with foreign genes.
- Uses:
- Study normal gene regulation & disease development.
- Biological products — human α-1 antitrypsin from transgenic sheep for emphysema.
- Vaccine safety — transgenic mice replace monkeys for polio vaccine testing.
- Chemical safety testing — toxicity in transgenic animals.
- First transgenic cow Rosie (1997) — produced human α-lactalbumin-enriched milk (2.4 g/L) — nutritionally more balanced for human babies.
Ethical Issues
- GEAC — Genetic Engineering Approval Committee (India) — reviews GMO safety and validity for public use.
Biopiracy
- Use of bio-resources by MNCs and organisations without authorisation or compensation to source countries.
- Rich nations tap the biodiversity of poor nations.
- Example: Turmeric, Basmati rice, Neem — patents granted (later revoked) in USA on traditional Indian knowledge.
- India has passed the Indian Patents Bill (Second Amendment) to prevent unauthorised exploitation.
Take-aways
- Genetic engineering has produced Bt cotton, RNAi tobacco, humulin insulin, gene therapy, transgenic animals.
- GEAC oversees GMO safety in India.
- Biopiracy is a major ethical issue — needs national laws to protect biodiversity.