Leafcutter ant queens shut down male-male sperm competition

Washington, March 19 (ANI): Leafcutter ant queen that mates with many males can stop the battle between competing sperm in her reproductive tract, a new research has found.

Queens of ants and bees normally obtain a lifetime supply of sperm on a single day of sexual activity, and sperm competition is expected to occur in lineages where queens receive sperm from multiple males.

Danish researchers who have studied ants at the Smithsonian Tropical Research Institute in Panama since 1992 discovered that in both ant and bee species, a male's seminal fluid favours the survival of its own sperm over the other males' sperm.

However, once sperm has been stored, leafcutter ant queens neutralize male-male sperm competition with glandular secretions in their sperm-storage organ.

"Two things appear to be going on here. Right after mating there is competition between sperm from different males. Sperm is expendable. Later, sperm becomes very precious to the female who will continue to use it for many years to fertilize her own eggs, producing the millions of workers it takes to maintain her colony," said Jacobus Boomsma, professor at the University of Copenhagen and Research Associate at STRI.

With post-doctoral researchers Susanne den Boer in Copenhagen and Boris Baer at the University of Western Australia, professor Boomsma studied sperm competition in sister species of ants and bees that mate singly-each queen with just one male-or multiply-with several males.

The results showed that the ability of a male's seminal fluid to harm the sperm of other males only occurs in species that mate multiply, and that their own seminal fluid does not protect sperm against these antagonistic effects.

The study has been published this week in the prestigious journal, Science. (ANI)