Genetic Switch Changes Eggs to Sperm that Create Viable Offspring

Scientists may have discovered a genetic switch that determines whether germ cells become sperm or eggs. The findings may tell researchers a bit more about reproduction.

The gene itself is named foxl3, which was first identified using a small fish called medaka. In medaka, without the gene's functionality, sperm would be produced in the ovaries of females. In fact, the sperm act normally and can produce normal offspring.

In females lacking functional foxl3 genes, the small fish's body appearance is still completely female. However a large number of sperm are formed in the ovaries, and a small number of eggs are formed at the same time. In addition, females lacking the function of foxl3 functional sperm can be obtained in a shorter period of time than in normal males.

"In spite of the environment surrounding the germ cells being female, the fact that functional sperm has been made surprised me greatly," said Toshiya Nishimura, one of the researchers, in a news release. "That this sexual switch is present in the Germ Cells is independent of the body's sex is an entirely new finding."

It turns out that this genetic switch can decide whether germ cells become egg or sperm. This, in turn, may have further implications for vertebrates and their reproduction in the future.

The findings are published in the journal Science.

Related Stories

Menopause: Culture May Influence Symptoms

Pheremones: Female Mice Can Only Mate When They Smell Their Partners

For more great science stories and general news, please visit our sister site, Headlines and Global News (HNGN).