Scientists unlock the secret to virgin birth in animals

A team of scientists has induced a virgin birth in an animal which usually reproduces sexually, and discovered the exact genetic cause for the phenomenon.

The unusual discovery was published on July 28 in the peer-reviewed Journal Current Biology, after the team from the University of Cambridge carried out research on the fruit fly Drosophila melanogaster.

“We’re the first to show that you can engineer virgin births to happen in an animal – it was very exciting to see a virgin fly produce an embryo able to develop to adulthood, and then repeat the process,” said Dr. Alexis Sperling, a researcher at the University of Cambridge.

She added: “In our genetically manipulated flies, the females waited to find a male for half their lives - about 40 days - but then gave up and proceeded to have a virgin birth.”

Six years of research into fly genetics

The research involved over 220,000 virgin fruit flies and took six years to complete.

The scientists first sequenced the genomes of two strains of another species of fruit fly, one of which needs males to reproduces, while the other only reproduces through a virgin birth. Then they identified the strands that were turned on or switched off when the flies reproduced without males present.

After they identified the relevant genes, the scientists then altered the corresponding genes in the model fruit fly, which then suddenly began reproducing without male involvement.

Dr. Sperling will continue her research in the Cambridge Crop Science Centre to investigate the reason why virgin births in certain insects are seemingly growing more common, particularly in pest species.

“If there’s continued selection pressure for virgin births in insect pests, which there seems to be, it will eventually lead to them reproducing only in this way. It could become a real problem for agriculture because females produce only females, so their ability to spread doubles,” said Sperling.

The rare phenomenon of virgin births in the animal kingdom isn't confined to flies but can also happen to birds, lizards and snakes. The females of some egg-laying animals can naturally switch to give birth without male presence, but this is mostly observed in female zoo animals which have been isolated for a long time.