How egg cloning works (in vitro gametogenesis)

1. Nucleus is removed from donor egg and replaced with a nucleus extracted from a parent’s skin cell

2. The donor egg discards half of its chromosomes, leaving a single set

Nucleus

Nucleus

Skin cell

Donor egg with

nucleus removed

Egg with a single

set of chromosomes

3. The egg can then be fertilised with sperm

4.The fertilised egg has an equal number of chromosomes from both parents

Sperm

1. Nucleus is removed from donor egg and replaced with a nucleus extracted from a parent’s skin cell

2. The donor egg discards half of its chromosomes, leaving a single set

3. The egg can then be fertilised with sperm

4.The fertilised egg has an equal number of chromosomes from both parents

Sperm

Nucleus

Nucleus

Skin cell

Donor egg with

nucleus removed

Egg with a single

set of chromosomes