Cloning Notes

Who Discovered Cloning?

• Ian Wilmut at the Roslin Institute in Scotland.

• Created the first mammal clone, Dolly the sheep.

Historical Background on Cloning

• First suggested by German embryologist Hans Spemann in 1938.

• Prior experiments in artificial twinning had been conducted.

Definition of Cloning

• Cloning refers to creating exact copies of an organism.

• Three main types of cloning:

  • Gene Cloning

  • Therapeutic Cloning

  • Reproductive (Embryo) Cloning

Gene Cloning

• Definition: Making identical copies of a gene or DNA segment.

• Key Terms:

  • Vector: Carrier transferring genetic material.

  • Ligation: Joining of 2 DNA molecules.

  • Plasmid: Circular DNA where the target gene is inserted.

  • Transformation: Introducing plasmid into bacteria.

• Process:

  1. DNA Extraction

  2. Ligation

  3. Transformation

  4. Colonial Expansion

  5. Selection of Recombinant Clones

  6. Gene Expression and Analysis

Therapeutic Cloning

• Clones only one cell to create stem cells independent of fertilized eggs.

• Process involves:

  1. Nucleus removal from an unfertilized egg.

  2. Nucleus removal from a donor cell.

  3. Injecting the donor nucleus into the egg.

  4. Stimulating division into a blastocyst.

  5. Extracting stem cells.

• Ethical concerns regarding human therapeutic cloning.

Reproductive/Embryo Cloning

• Involves cloning the whole organism from an early embryo.

Example of Cloning: Dolly the Sheep

• First mammal cloned from an adult somatic cell using somatic cell nuclear transfer (SCNT).

Identical Twins Comparison

• Not clones but similar; arise from one fertilized egg splitting.

Applications of Gene Cloning

• Production of insulin in labs for diabetes.

Pros and Cons of Cloning

• Pros:

  • Medical advancements.

  • Scientific research possibilities.

• Cons:

  • High failure rates.

  • Health risks.

  • Loss of genetic diversity.