Featured Research

from universities, journals, and other organizations

Females shut down male-male sperm competition in leafcutter ants

Date:
April 26, 2010
Source:
Smithsonian Tropical Research Institute
Summary:
Danish researchers who have studied ants in Panama since 1992 discovered that in both ant and bee species in which queens have multiple mates, a male's seminal fluid favors 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.

Leafcutter ant workers carry leaf pieces down into underground nests where they use them as fertilizer for their fungus garden. Ants eat the fungus, not the leaves.
Credit: STRI

Leafcutter ant queens can live for twenty years, fertilizing millions of eggs with sperm stored after a single day of sexual activity.

Danish researchers who have studied ants at the Smithsonian Tropical Research Institute in Panama since 1992 discovered that in both ant and bee species in which queens have multiple mates, a male's seminal fluid favors 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," explains Jacobus Boomsma, professor at the University of Copenhagen and Research Associate at STRI. "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."

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.

Their results, published in the journal Science, show 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.

"Females belonging to many species -- from vertebrates to insects-- have multiple male partners. Seminal products evolve rapidly, probably in response to the intense male-male competition that continues even after courtship and mating have taken place," said William Eberhard, Smithsonian staff scientist. "This study continues the STRI tradition of looking at post-copulatory selection in a very biodiverse range of organisms, following in the footsteps of people like Bob Silberglied, who asked why butterflies and moths have two kinds of sperm in the 1970's."

Similar sperm competition systems appear to have evolved independently in ants and in bees. Researchers now aim to discover how genes that control sperm recognition in bees and ants may differ, thus continuing to elucidate the details of a process key to reproduction and evolution.

A grant from the Danish National Research Foundation and an Australian Research Council Fellowship supported this work. Permits for ant collection and export were issued by Panama's Autoridad Nacional de Ambiente (ANAM).


Story Source:

The above story is based on materials provided by Smithsonian Tropical Research Institute. Note: Materials may be edited for content and length.


Journal Reference:

  1. Susanne P. A. den Boer, Boris Baer, and Jacobus J. Boomsma. Seminal fluid mediates ejaculate competition in social insects. Science, 2010: 1506-1509 DOI: 10.1126/science.1184709

Cite This Page:

Smithsonian Tropical Research Institute. "Females shut down male-male sperm competition in leafcutter ants." ScienceDaily. ScienceDaily, 26 April 2010. <www.sciencedaily.com/releases/2010/03/100318141555.htm>.
Smithsonian Tropical Research Institute. (2010, April 26). Females shut down male-male sperm competition in leafcutter ants. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/2010/03/100318141555.htm
Smithsonian Tropical Research Institute. "Females shut down male-male sperm competition in leafcutter ants." ScienceDaily. www.sciencedaily.com/releases/2010/03/100318141555.htm (accessed July 28, 2014).

Share This




More Plants & Animals News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Sea Turtle Hatchlings Emerge from Nest

Raw: Sea Turtle Hatchlings Emerge from Nest

AP (July 27, 2014) A live-streaming webcam catches loggerhead sea turtle hatchlings emerging from a nest in the Florida Keys. (July 27) Video provided by AP
Powered by NewsLook.com
Trees Could Save More Than 850 Lives Each Year

Trees Could Save More Than 850 Lives Each Year

Newsy (July 27, 2014) A national study conducted by the USDA Forest Service found that trees collectively save more than 850 lives on an annual basis. Video provided by Newsy
Powered by NewsLook.com
What's To Blame For Worst Ebola Outbreak In History?

What's To Blame For Worst Ebola Outbreak In History?

Newsy (July 27, 2014) A U.S. doctor has tested positive for the deadly Ebola virus, as the worst-ever outbreak continues to grow. Video provided by Newsy
Powered by NewsLook.com
The New York Times Backs Pot Legalization

The New York Times Backs Pot Legalization

Newsy (July 27, 2014) The New York Times has officially endorsed the legalization of marijuana, but why now, and to what end? Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins