Infertility

The cells that eventually turn into either eggs or sperm – known as germ cells – are identical in male and female embryos.

“Whether a germ cell develops into an egg or a sperm depends on the time at which meiosis begins,” Professor Koopman said.

“In females, meiosis begins before birth and eggs are produced, whereas in males, meiosis begins after birth and the result is sperm.” Professor Koopman and his team found that retinoic acid, a derivative of Vitamin A, causes germ cells in female embryos to begin meiosis, leading to the production of eggs.

They also discovered an enzyme present in male embryos that wipes out retinoic acid and so suppresses meiosis until after birth, resulting in sperm production.

“This is an extremely important process that nobody has been able to figure out until now,” Professor Koopman said.

“It is textbook science and it should provide the basis for a number of practical applications.” Knowledge of what triggers and suppresses meiosis may allow researchers to improve fertility, for example in the case of an infertile couple wanting a baby, or suppress it, in the case of pest management.

Professor Koopman also suggested that an ...

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