Biotechnology and its Applications

• Biotechnological Applications in Agriculture

  • Bt Cotton
    • Source organism: Bacillus thuringiensis
    • Mechanism: Produces cry proteins (crystal proteins)
    • Target pests: Lepidopteran insects (cotton bollworms)
    • Action: Inactive toxin ingested $\rightarrow$ activated in alkaline gut $\rightarrow$ epithelial cell lysis $\rightarrow$ insect death
  • Pest-Resistant Plants
    • RNA Interference (RNAi) mechanism
    • Target: Parasitic nematodes (e.g., Meloidegyne incognita)
    • Process: Silencing of specific mRNA using dsRNA
  • Other Applications
    • Increased nutritional value (e.g., Golden Rice rich in Vitamin A)
    • Tolerance to abiotic stresses (cold, drought, salt, heat)
    • Reduced reliance on chemical pesticides

• Biotechnological Applications in Medicine

  • Genetically Engineered Insulin (Humulin)
    • Problem: Animal-sourced insulin caused allergies
    • Solution: Recombinant DNA technology in E. coli
    • Structure: Two polypeptide chains (A and B) linked by disulfide bonds
  • Gene Therapy
    • Definition: Correction of gene defects in children/embryos
    • Example: Treatment of ADA deficiency (Adenosine deaminase)
    • Permanent cure: Introduction of functional gene into bone marrow cells at early embryonic stages
  • Molecular Diagnostics
    • PCR (Polymerase Chain Reaction): Detects very low concentrations of pathogens/mutations
    • Recombinant DNA Technology: Identifies mutated genes in cancer/genetic disorders
    • ELISA (Enzyme-Linked Immunosorbent Assay): Based on antigen-antibody interactions (detects HIV)

• Transgenic Animals

  • Definition: Animals with manipulated DNA to express foreign genes
  • Purposes of Transgenic Animals
    • Study of normal physiology and development: How genes are regulated and affect body functions
    • Study of diseases: Models for human diseases (cancer, cystic fibrosis, Alzheimer's)
    • Biological products: Production of human proteins (e.g., Alpha-1 antitrypsin for emphysema, Alpha-lactalbumin enriched milk)
    • Vaccine safety: Testing safety of polio vaccines before use on humans
    • Chemical safety testing: Toxicity testing with reduced animal harm

• Ethical Issues and Biopiracy

  • GEAC (Genetic Engineering Appraisal Committee)
    • Function: Makes decisions regarding validity of GM research and safety of introducing GM-organisms for public services
  • Biopiracy
    • Definition: Use of bio-resources by multinational companies without proper authorization/compensatory payment
    • Target: Traditionally rich biodiversity countries (e.g., developing nations like India)
    • Controversies: Patenting of Indian Basmati rice, Turmeric, and Neem by foreign corporations
  • Indian Patent Act
    • Modifications made (e.g., Second Amendment) to prevent unauthorized biopiracy and protect indigenous knowledge systems