Researchers retrieve spermathecal fluid from the abdomen of a female ant - this fluid controls how long rival male's ejaculates continue to damage each other.
Credit: Boris Baer/UWA
SYDNEY: The queen of a social insect colony has one sexual encounter during her life, which involves many males, then controls which sperm will die off, researchers said.
A social insect queen only experiences a single day of sexual activity in her lifetime yet she must obtain all the sperm necessary to create an entire colony within that time frame. This means that social insect females store a large amount of sperm in their storage organ.
"A honeybee queen mates with many more males than she has to, thereby collecting much more sperm than she actually needs," said Boris Baer, from the University of Western Australia in Crawley.
Rival sperm fight
After males have transferred their ejaculates to the female, the ejaculates start competing and damaging each other. This competition is beneficial to some extent because it ensures that the best quality sperm will be stored and used to sire offspring, said Baer.
Baer, together with collaborators from the University of Copenhagen in Denmark, looked at two species of corbiculate bees and three species of fungus growing ants. They used an in-vitro sperm survival assay to test the effects of an ant's own accessory gland (AG) secretion - this secretion is the main contributor of seminal fluid and ensures reproductive success by protecting sperm cells after ejaculation.
The researchers also looked at the AG secretion of other males, and queen spermathecal fluid on individual sperm survival.
Queen manipulates male sperms
The researchers discovered that the female has the ability to stop the ejaculates from competing and dying in her abdomen by using spermathecal secretions, Baer said.
In Atta leafcutter ants, the queen's sperm storage organ inhibits the negative affects of male sperm upon one another, suggesting that the queen manipulates competition between the different male ejaculates, said Baer, who published his findings in the journal Science.
Baer concluded that mixtures of spermathecal fluid from the queen and the seminal fluid of a potential rival male preserve sperm survival of a focus male at normal levels. This provides evidence that spermathecal fluid has the ability to subdue damaging male AG secretions of rival males.
A strange little universe
A truly fascinating subject from a strange little world where males were surely taught their proper place in life.
A very well written article.