Science - Cloning

Cloning

• A clone is an organism that was made by exactly copying the genetic sequence of another organism. Cloning occurs in nature. Examples of natural cloning include mitosis and banana plants.
• Types of cloning:
  • Nuclear Transfer Cloning:
    • Somatic: any cell that is not a sperm or egg.
    • The nucleus of one somatic cell and egg cell is taken out and the somatic cell’s nucleus is implanted into the egg’s empty space where its nucleus used to be
    • Eventually the egg begins to divide (this does not always happen, and is why Nuclear Transfer Cloning is not very efficient), and becomes a full organism
  • Therapeutic Cloning: An embryo is cloned in the normal way, but instead of letting it develop into a fetus/organism, it’s interrupted at the blastocyst stage (when it’s still just a ball of cells) and used to repair cellular damage to a patient.
    • This is useful because the cells in a blastocyst are “stem cells”: they have not yet differentiated, so they can become any kind of tissue needed.
    • Therapeutic

Dolly the Sheep

Dolly the Sheep was the first ever mammal to be cloned

• 1/400 attempts successful
• around 300 embryos used
• Dolly died at 6 years old (most sheep die at around 12) due to a lung disease, NOT cloning
• First step towards human cloning
• Cloning the best cattle for meat and milk production
• Embryonic stem cells for medical use
• Clones as “spare parts” for humans
• Negatively affected stem cell research by association
• Cloning research moved to countries with less restrictions (Such as China and Japan)