Pocket Notes — Biotechnology and its Applications
Three application areas
- Agriculture (GM plants, Bt crops, RNAi).
- Medicine (recombinant insulin, gene therapy, molecular diagnosis).
- Environment (transgenic animals, product manufacturing).
Bt cotton essentials
- Bt toxin genes: cryIAc, cryIIAb (bollworms); cryIAb (corn borer).
- Toxin is inactive protoxin in bacterium; activated in insect gut's alkaline pH.
- Introduced into cotton — resistant to cotton bollworm.
RNA Interference (RNAi)
- Silencing of specific mRNA by complementary dsRNA / siRNA.
- Example: nematode Meloidogyne incognita on tobacco.
- Vector: Agrobacterium tumefaciens.
Recombinant insulin
- Structure: A chain (21 aa) + B chain (30 aa), joined by disulfide bonds.
- Made as pre-proinsulin → proinsulin → insulin (C-peptide removed).
- Humulin (1983, Eli Lilly): chains synthesised separately in E. coli, then joined.
Gene therapy landmarks
- 1990 — first gene therapy: SCID due to ADA deficiency.
- Adenosine deaminase gene inserted into lymphocytes → returned to patient.
- Permanent cure requires bone-marrow stem cell insertion.
Molecular diagnosis tools
| Method | Detects |
|---|
| PCR | HIV, cancer mutations, TB |
| ELISA | Antigens/antibodies (HIV) |
| DNA probes / hybridisation | Specific mutations |
Transgenic animals — key examples
| Animal | Product / purpose |
|---|
| Rosie (transgenic cow, 1997) | Milk with human α-lactalbumin (2.4 g/L) |
| Transgenic sheep | α-1-antitrypsin (treats emphysema) |
| Transgenic mice | Testing polio vaccine safety |
Ethical body
GEAC — Genetic Engineering Approval Committee (India) — approves GMOs.
Biopiracy hot examples
- Turmeric patent in USA (revoked).
- Basmati rice patent in USA (revoked).
- Neem patent in Europe (revoked).
- India — Indian Patents Bill (Second Amendment) to counter biopiracy.
Cry protein specificity
- cryIAc, cryIIAb: cotton bollworm.
- cryIAb: corn borer.
Quick MCQ traps
- Which insulin chain has 21 aa? — A chain.
- Which chain has 30 aa? — B chain.
- What links A and B? — Disulfide bridges.
- What is C peptide? — connecting peptide removed during processing.
- Where does Bt toxin get activated? — Alkaline gut pH of insect.
- Who is Rosie? — First transgenic cow with humanised milk.
- First disease treated by gene therapy? — SCID (ADA deficiency).
Pocket Notes — Biotechnology and its Applications
Three application areas
- Agriculture (GM plants, Bt crops, RNAi).
- Medicine (recombinant insulin, gene therapy, molecular diagnosis).
- Environment (transgenic animals, product manufacturing).
Bt cotton essentials
- Bt toxin genes: cryIAc, cryIIAb (bollworms); cryIAb (corn borer).
- Toxin is inactive protoxin in bacterium; activated in insect gut's alkaline pH.
- Introduced into cotton — resistant to cotton bollworm.
RNA Interference (RNAi)
- Silencing of specific mRNA by complementary dsRNA / siRNA.
- Example: nematode Meloidogyne incognita on tobacco.
- Vector: Agrobacterium tumefaciens.
Recombinant insulin
- Structure: A chain (21 aa) + B chain (30 aa), joined by disulfide bonds.
- Made as pre-proinsulin → proinsulin → insulin (C-peptide removed).
- Humulin (1983, Eli Lilly): chains synthesised separately in E. coli, then joined.
Gene therapy landmarks
- 1990 — first gene therapy: SCID due to ADA deficiency.
- Adenosine deaminase gene inserted into lymphocytes → returned to patient.
- Permanent cure requires bone-marrow stem cell insertion.
Molecular diagnosis tools
| Method | Detects |
|---|
| PCR | HIV, cancer mutations, TB |
| ELISA | Antigens/antibodies (HIV) |
| DNA probes / hybridisation | Specific mutations |
Transgenic animals — key examples
| Animal | Product / purpose |
|---|
| Rosie (transgenic cow, 1997) | Milk with human α-lactalbumin (2.4 g/L) |
| Transgenic sheep | α-1-antitrypsin (treats emphysema) |
| Transgenic mice | Testing polio vaccine safety |
Ethical body
GEAC — Genetic Engineering Approval Committee (India) — approves GMOs.
Biopiracy hot examples
- Turmeric patent in USA (revoked).
- Basmati rice patent in USA (revoked).
- Neem patent in Europe (revoked).
- India — Indian Patents Bill (Second Amendment) to counter biopiracy.
Cry protein specificity
- cryIAc, cryIIAb: cotton bollworm.
- cryIAb: corn borer.
Quick MCQ traps
- Which insulin chain has 21 aa? — A chain.
- Which chain has 30 aa? — B chain.
- What links A and B? — Disulfide bridges.
- What is C peptide? — connecting peptide removed during processing.
- Where does Bt toxin get activated? — Alkaline gut pH of insect.
- Who is Rosie? — First transgenic cow with humanised milk.
- First disease treated by gene therapy? — SCID (ADA deficiency).