Cloning Explained

Probably the most famous sheep is Dolly.  She was cloned in 1998 by the Roslin Institute near Edinburgh.  The cloning process involved removing a body cell from a sheep and extracting the cell nucleus.  This was then placed next to an egg cell which had it's own nucleus removed.  A small electric shock then caused the egg cell to take in the new nucleus.  The egg cell was then inserted into the host sheep where it grew into a lamb. 

Step 1 - harvest a body (somatic cell) and extract the nucleus

Step 2 - harvest an egg cell

Step 3 - remove the nucleus from the egg cell 

Step 4 - place the empty egg beside the extracted nucleus and give a small electric shock  

Step 5 - another shock encourages the new egg to divide and grow 

Step 6 - the growing embryo is transplanted into a host sheep where it grows into a lamb