Transgenic Animals 🧬

A transgenic animal carries and actively shows an extra (foreign) gene that scientists add to its DNA. Mice make up over 95 % of all such animals, but researchers have also created transgenic rats, rabbits, pigs, sheep, cows, and even fish. :contentReference[oaicite:0]{index=0}

Why Do Scientists Create Them? 🤔

  1. Understand Normal Body Functions 🔬
    By adding or tweaking specific genes, researchers watch how the body grows and works—for example, how insulin-like growth factor guides growth. This reveals which genes switch on (or off) during everyday life. :contentReference[oaicite:1]{index=1}
  2. Model Human Diseases 🧑‍⚕️
    Specially bred animals mimic disorders such as cancer, cystic fibrosis, rheumatoid arthritis, and Alzheimer’s disease. Doctors then test new treatments in these living “practice grounds” before moving to human trials. :contentReference[oaicite:2]{index=2}
  3. Produce Life-Saving Bioproducts 💉
    Inserting human genes lets animals make helpful proteins, e.g. α-1-antitrypsin for emphysema therapy. In 1997, the cow Rosie 🐄 gave milk enriched with human α-lactalbumin (≈ 2.4 g L⁻¹), offering a more balanced infant feed than ordinary cow’s milk. Similar projects aim to help phenylketonuria (PKU) and cystic fibrosis patients. :contentReference[oaicite:3]{index=3}
  4. Check Vaccine Safety 💉🛡️
    Transgenic mice test vaccines (for instance, the polio vaccine) before doctors give them to people, potentially replacing monkey testing. This shortens the path from lab bench to clinic. :contentReference[oaicite:4]{index=4}
  5. Study Chemical Safety (Toxicity) ☠️
    Some animals receive genes that make them extra-sensitive to toxins. When exposed, they show harmful effects quickly, giving faster and clearer safety data on new chemicals or medicines. :contentReference[oaicite:5]{index=5}

High-Yield Ideas for NEET 🔑

  • Definition of a transgenic animal and common species used (focus on mice). :contentReference[oaicite:6]{index=6}
  • Five major applications—physiology & development, disease models, bioproducts, vaccine testing, toxicity testing. :contentReference[oaicite:7]{index=7}
  • Real-world example: Rosie the transgenic cow producing human protein-rich milk. :contentReference[oaicite:8]{index=8}
  • Therapeutic protein examples like α-1-antitrypsin for emphysema. :contentReference[oaicite:9]{index=9}
  • Use of transgenic mice to ensure vaccine safety (e.g., polio) before human use. :contentReference[oaicite:10]{index=10}

✨ Happy studying! ✨