Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Symbiotic fungus does not depend on fungus-farming ants for reproduction, researchers say

28.06.2006
Fungus-farming ants around the world cultivate essentially the same fungus and are not as critical to the reproduction of the fungi as previously believed, biologists at The University of Texas at Austin have discovered.

Fungus-farming ants are dependent on cultivating fungus gardens for food, and it has been widely believed the fungi also evolved dependence on the ants for their dispersal and reproduction. When young ant queens establish new colonies, they take a start-up crop of fungi with them from their parental garden.


A leaf-cutting ant queen (Acromyrmex coronatus) is sheltered in a chamber deep inside of her fungus garden, made of leaf fragments and strands of a symbiotic fungus. The garden was grown from a few strands brought by the queen on her mating flight from the maternal garden. After the mating flight, the queen never leaves her garden metropolis. Credit: Alexander Mikheyev and Barrett Klein

Graduate student Alexander Mikheyev and Dr. Ulrich Mueller, professor of integrative biology, have now found that the fungi reproduce sexually and disperse widely without the aid of their ant farmers.

Different genera of the ants, it turns out, are essentially cultivating the same fungus across wide geographical areas.

The scientists' finding provides a new perspective on coevolutionary processes. Coevolution, like that between honeybees and the flowers they pollinate, occurs when two or more species influence each other's evolution over time. Mikheyev says that two species don't necessary need to have a very specific, one-to-one relationship in order to coevolve.

"This shows that coevolution can proceed without specificity at the species level," said Mikheyev. "It has been believed that mutualistic interactions, as well as parasitic ones, are very specific and one-to-one. We are beginning to realize that this is not necessary for long-term coevolutionary stability, with the leaf-cutting ants being a dramatic example."

The research was published June 26 in Proceedings of the National Academy of Sciences.

"Previously, the fungi were thought to be passive players, moved around by the ants," said Mikheyev. "We show that the power of fungal dispersal is probably beyond ant control."

Observations of the fungi reproducing sexually--producing a fruiting body or mushroom--deep inside an ant nest are extremely rare. So the scientists, in collaboration with Dr. Patrick Abbot at Vanderbilt University, read the signatures of sexual reproduction in the fungal genes. They studied fungi cultivated by leaf-cutting ants, well known fungus farmers that bring pieces of leaves back to their nest to use as a growth medium for their fungi.

Genetic analysis revealed that the fungi are still using the cellular machinery necessary for sexual reproduction, which would have been lost or changed had the fungi become completely dependent on asexual, clonal reproduction through their ant farmers.

Studying the fungus gardens of an introduced population of leaf-cutting ants on the French Caribbean island of Guadeloupe, the scientists also found that the fungal genes have been recombining, a sign they are reproducing with one another.

"The fungi are not completely domesticated and under the strict control of the ants," said Mueller. "Instead, the fungi occasionally have a life of their own, dispersing independently of the ants and exchanging genes with other ant-cultivated fungi."

Mikheyev, Mueller and Abbot also compared leaf-cutter ants and their fungal crops from Cuba to populations of ants and fungi from Central and South America. Though the Cuban ants have been isolated from mainland populations for many years, genetic analysis showed their fungal crops have been exchanging genes with mainland fungi populations.

"The fungi are able to cross geographical boundaries too great for the ants, intermingling genes between mainland and Cuban populations, possibly through airborne spores," said Mikheyev.

Ulrich Mueller | EurekAlert!
Further information:
http://www.utexas.edu

More articles from Life Sciences:

nachricht Two Group A Streptococcus genes linked to 'flesh-eating' bacterial infections
25.09.2017 | University of Maryland

nachricht Rainbow colors reveal cell history: Uncovering β-cell heterogeneity
22.09.2017 | DFG-Forschungszentrum für Regenerative Therapien TU Dresden

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Highest-energy cosmic rays have extragalactic origin

25.09.2017 | Physics and Astronomy

Two Group A Streptococcus genes linked to 'flesh-eating' bacterial infections

25.09.2017 | Life Sciences

NASA'S OSIRIS-REx spacecraft slingshots past Earth

25.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>