By using embryonic stem cells and skin cells, artificial human eggs and sperm have been created by researchers for the first time. Scientists from Cambridge University have achieved the feat by doing so with humans as it was previously done only with rats. Details of the study have been published in the journal Cell.

The sperm and eggs are not working ones, but are so-called germ cells that are capable of becoming viable for fertility. "Germ cells are 'immortal' in the sense that they provide an enduring link between all generations, carrying genetic information from one generation to the next", said Azim Surani, professor of physiology and reproduction at the University of Cambridge.

After a sperm fertilizes an egg, it divides into a group of cells called a blastocyst. After this, it develops into a fetus or the placenta.

Some cells become stem cells and have the tendency of developing into any cell in the body. Some of these become germ cells and eventually turn into either sperm or eggs.

The scientists said that SOX17 is a gene that decides which cells become sperm and egg cells. Scientists harvested these cells by culturing human embryonic stem cells for five days. But this does not imply that men and women can donate any cells instead of sperm and eggs when they visit a fertility clinic. Scientists are optimistic that the experiment will help in getting further insight into the study of human genetics.

Scientists have also come across a new way through the study to examine how genes are impacted by the environment, like behavioral factors, including smoking and what we eat.

Epigenetics is a terminology used for the study that looks into how genes are affected by environmental factors. Scientists are of the belief that it will help them get a better understanding of cancer and other age-related illnesses.