Definition:

• Animals manipulated to possess and express foreign genes termed transgenic animals.
• Commonly produced in rats, rabbits, pigs, sheep, cows, fish, with mice dominating over 95% of transgenic animals.

Purposes and Benefits:

• 1. Normal Physiology and Development:

  • Design Specificity: Engineered to study gene regulation impact on normal body functions and development.
  • Example: Introduction of genes altering insulin-like growth factor formation for in-depth biological role exploration.

• 2. Study of Disease:

  • Understanding Genetic Contributions: Transgenic animals serve as models for human diseases, aiding investigation of new treatments.
  • Existing Models: Models for cancer, cystic fibrosis, rheumatoid arthritis, Alzheimer’s, facilitating disease mechanism exploration.

• 3. Biological Products:

  • Medicine Production: Creation of transgenic animals producing valuable biological products.
  • Examples: Production of human proteins like α-1-antitrypsin for treating emphysema; efforts for treating phenylketonuria (PKU) and cystic fibrosis.
  • Landmark Achievement: Rosie, the first transgenic cow (1997), produced human protein-enriched milk, nutritionally superior for human babies.

• 4. Vaccine Safety:

  • Reliable Testing: Development of transgenic mice for pre-human vaccine safety testing.
  • Example: Transgenic mice used to test polio vaccine safety, potentially replacing monkey testing.

• 5. Chemical Safety Testing (Toxicity/Safety Testing):

  • Accelerated Results: Transgenic animals designed to be more sensitive to toxic substances for faster toxicity testing.
  • Efficiency: Facilitates quicker toxicity results compared to non-transgenic animals.