GE In-Depth GE In-Depth
     

GE Basics
Locating Genetic Information

Timeline of GE

Processes
Recombinant DNA:
How Genes Are Transferred

   

Recombinant DNA: Example Using Insulin

Cloning:
How To Make Identical Genomes

 

 

  Cloning: How To Make Identical Genomes
 

Cloning is a process used to create an exact copy of a mammal by using the complete genetic material of a regular body (somatic) cell. These steps describe the basic process used to clone Dolly the sheep. This was the first successful cloning of a mammal.

Move you mouse over each picture to see how cloning happens.

  1. Isolate donor nucleus
  2. Get unfertilized eggs
  3. Remove the egg's nucleus
  4. Insert donor nucleus
  5. Place the egg into womb

1. Isolate donor nucleus

Isolate the nucleus from a somatic (non-reproductive) cell of a adult donor sheep. The nucleus contains the complete genetic material of the organism. This step is repeated many times to gather many cell nuclei. A very small needle and syringe (suction device) is used to poke through the cell membrane to capture the nucleus and remove it from the cell.

2.Get unfertilized eggs

Retrieve unfertilized egg cells (reproductive) from a female sheep. Many eggs are needed since not all of them will survive the various steps of cloning.


3. Remove the egg's nucleus

Remove the egg cell's nucleus, which contains only one-half of the sheep's genetic material. A very small needle and syringe (suction device) is used to poke through the cell membrane to capture the nucleus and remove it from the cell.

4. Insert donor nucleus

Insert the nucleus, with its complete genetic material, isolated from the donor mammal in Step 1 into the egg cell that has no nuclear material. The egg's genetic material now contains all traits from the donor adult. This egg is genetically identical to the donor adult.

5. Place the egg into womb

Place the egg into a female sheep's womb. Only a small percentage of eggs placed in the womb will start to mature. Those eggs that survive will continue to develop into embryos. The egg matures in the womb. When the offspring is born, it is a clone (genetically identical) of the donor sheep.


Explore More: Genetic Engineering
Copyright 2004, Iowa Public Television
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