DISCOVERIES
Virgin birth gene identified in Cape bees
All the month’s biggest science news. This issue: rare, doughnut-shaped galaxy discovered; virgin birth in bees; heart’s nervous system mapped; SpaceX’s Dragon capsule successfully docks with ISS.
The Cape bee is a subspecies of honeybee that’s native only to the southern tip of South Africa. What makes it different from other honeybees is that the female worker bees are able to lay eggs that develop into other female bees. These eggs are not fertilised (worker bees are unable to mate), so this is a form of asexual reproduction, known as ‘thelytoky’. The Cape bees are essentially creating a clone.
In Cape bees, this cloning trick only develops once the colony’s queen bee dies. By producing female bees, they can give birth to the colony’s new queen, ensuring that the colony survives.
In other honeybee subspecies, if the queen is lost the worker bees will occasionally lay unfertilised eggs, but these only develop into males, leading to the eventual collapse of the colony.
The Cape bee’s ability comes at a cost, though. “Instead of being a cooperative society, Cape honeybee colonies are riven
with conflict because any
worker can be genetically reincarnated as the next queen,” said study leader Prof Benjamin Oldroyd at the University of Sydney, Australia. “When a colony loses its queen, the workers
fight and compete to be the
mother of the next queen.”
By comparing the genetic sequences (‘genomes’) of
Cape bees to those of other honeybee subspecies,
Oldroyd and colleagues were able to identify the gene that causes these births, called ‘GB45239’. “It is extremely exciting,” said Oldroyd. “Scientists have been looking for this gene for the last 30 years. Now that we know it’s on chromosome 11, we have solved a mystery.”
According to Oldroyd, continued research into the Cape honeybees could help us understand two major evolutionary transitions: the origin of sex and the origin of animal societies.
Furthermore, the scientists think that if they could decipher exactly how the gene works, it could raise the possibility of controlling a switch that allows animals to reproduce asexually, which could have important implications for agriculture and other fields.