Artificial clones in animals

• Natural cloning in animals

  • Cloning must start with cells that are totipotent
  • Reproductive cloning is used to produce large numbers of genetically identical animals
• Totipotent


  Can differentiate into anything
• Embryo splitting

  1. after fertilisation, the 8 cell embryo is collected
  2. The 8 cell embryo is split into 4 2-cell embryos
  3. Each new embryo is implanted into a surrogate cow and grows into a calf

  • calves will be genetically identical
  • calves not identical to parents
• Non-reproductive cloning 


  Therapeutic cloning - stem cells used to replace cells, tissues or organs which may be used to treat diseases (tissue culture)
• Somatic cell nuclear transfer (SCNT)

  
• Reproductive cloning

  
• Animal cloning

  1. A sheep’s udder cell has the nucleus removed - it is enucleated
  2. The nucleus is removed from the sheeps egg cell
  3. The udder cell nucleus is inserted into enucleated egg cell
  4. An electric shock is given to the egg cell which stimulate it to start dividing
  5. The developing embryo is inserted into the surrogate mother
  6. The foetus is a clone of the udder cell donor organism
• Advantages

  • Genetically modified animals can be produced quickly
  • Rare animals cloned to preserve populations
  • High value animals can be cloned in large numbers
• Disadvantages

  • Unclear whether cloned animals remain healthy in the long term
  • Genetic uniformity
  • High value animals usually produced with little regard to animals welfare
  • Technology opposes teachings of the church and that god created all life