Men's Eggs, Women's Sperm: Stem Cell Science May Change How We Reproduce

In theory, a skin cell from a man could be turned into an egg and a skin cell from a woman can become a sperm.

It may soon be possible to coax human skin cells into becoming functional eggs and sperm using a technique known as “in vitro gametogenesis”. This involves the creation (genesis) of eggs and sperm (gametes) outside the human body (in vitro).

In theory, a skin cell from a man could be turned into an egg and a skin cell from a woman can become a sperm. Then there's the possibility of a child having multiple genetically-related parents, or only one.

Some scientists believe human applications of in vitro gametogenesis are a long way off.