Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Antarctic and Arctic Insects Use Different Genetic Mechanisms to Cope With Lack of Water

13.03.2013
Genomic techniques facilitate discovery that gene expression causes disparity
Although they live in similarly extreme ecosystems at opposite ends of the world, Antarctic insects appear to employ entirely different methods at the genetic level to cope with extremely dry conditions than their counterparts that live north of the Arctic Circle, according to National Science Foundation- (NSF) funded researchers.

Writing in the Proceedings of the National Academy of Sciences, the researchers concluded, "Polar arthropods have developed distinct... mechanisms to cope with similar desiccating conditions."

The researchers noted that aside from the significance of the specific discovery about the genetics of how creatures cope in polar environments, the new finding is important because it shows how relatively new and developing scientific techniques, including genomics, are opening new scientific vistas in the Polar Regions, which were once thought to be relatively uniform and, relatively speaking, scientifically sterile environments.

"It's great to have an Antarctic animal that has entered the genomic era," said David Denlinger, a distinguished professor of entomology at Ohio State University and a co-author of the paper. "This paper, which analyzed the expression of thousands of genes in response to the desiccating environment of Antarctica, is just one example of the power that the genomic revolution offers for advancing polar science. "

The collaborative research--which included contributions from scientists at Ohio State University, the Centre National de la Recherche Scientifique (National Center for Scientific Research) in France, Catholic University of Louvain in Belgium, Stanford University, and Miami University in Ohio--was supported in part by the Division of Polar Programs in NSF's Geosciences Directorate.

Polar Programs manages the U.S. Antarctic Program, through which it coordinates all U.S. research on the southernmost continent and aboard ships in the Southern Ocean as well as providing the necessary logistical support.

The finding also adds to the developing picture of the Polar Regions as having similarities and yet subtle and perhaps very important differences, previously undetected by science. NSF-funded scientists late last year, for example, published research indicating that differing contributions of freshwater from glaciers and streams to the Arctic and Southern oceans may be responsible for the fact that the majority of microbial communities that thrive near the surface of the Polar oceans share few common members.

Although Antarctica's surrounding oceans and coastal margins are home to a variety of large creatures such as seals, penguins and whales, insect life is rare, except on the Antarctic Peninsula.

There, the Antarctic midge, Belgica antarctica, occupies its unique ecological niche.

The research team that produced the new findings collected specimens for their research from offshore islands near NSF's Palmer Station on Anvers Island in the Peninsula region.

Surrounded by an ocean, the Antarctic continent is a polar desert where creatures have adapted to life with infrequent access to liquid water. The researchers note that Antarctic midge larvae, for example, "are remarkably tolerant of dehydration, surviving losses of up to 70 percent of their body water."

They also note that, in general, "insects, in particular, are at high risk of dehydration because of their small body size and consequent high surface-area-to-volume ratio."

Among Antarctic insects, the ability to tolerate dehydration is an important evolutionary development, allowing the creatures to successful survive the cold and dry southern winter.

"The loss of water enhances acute freezing tolerance," they write. "In addition, overwintering midge larvae are capable of undergoing another distinct form of dehydration, known as cryoprotective dehydration.

Cryoprotective dehydration is a mechanism in which a gradual decrease in temperature in the presence of environmental ice "creates a vapor pressure gradient that draws water out of the body, thereby depressing the body fluid melting point and allowing larvae to remain unfrozen at subzero temperatures."

The researchers compared the midge's strategy to those of other terrestrial arthropods that cope with prolonged periods when water is lacking, including the Arctic springtail Megaphorura arctica and Folsomia candida, which are more widely distributed across the globe; both species are members of a group of arthropods, which are closely related to insects, known as Collembola.

The differences, they concluded, lie in the way that various genes express themselves.

After a detailed analysis of gene expression in the various species, the researchers concluded that "although B. antarctica and M. arctica are adapted to similar environments, our analysis indicated very little overlap in expression profiles between these two arthropods."

They add that "these differences in expression patterns may reflect different strategies for combating dehydration; whereas B. antarctica shuts down metabolic activity and waits for favorable conditions to return, F. candida [instead] relies on active water-vapor absorption to restore water balance during prolonged periods of desiccation."

They further add that because of the taxonomic difference between the Antarctic midge and the collembolan species with which gene expression was compared, more work is needed "to better understand the evolutionary physiology of dehydration tolerance in this taxonomic family."

Media Contacts
Peter West, NSF (703) 292-7530 pwest@nsf.gov
Program Contacts
Diana Nemergut, NSF (703) 292-7448 dnemergu@nsf.gov
Principal Investigators
David Denlinger, Ohio State University (614) 292-6425 denlinger.1@osu.edu
Richard E Lee Jr., Miami University (513) 529-3141 leere@miamioh.edu

The National Science Foundation (NSF) is an independent federal agency that supports fundamental research and education across all fields of science and engineering. In fiscal year (FY) 2012, its budget is $7.0 billion. NSF funds reach all 50 states through grants to nearly 2,000 colleges, universities and other institutions. Each year, NSF receives over 50,000 competitive requests for funding, and makes about 11,000 new funding awards. NSF also awards nearly $420 million in professional and service contracts yearly.

Peter West | EurekAlert!
Further information:
http://www.nsf.gov

Further reports about: Antarctic Predators Arctic Ocean Genetic clues NSF Polar Day Water Snake insects

More articles from Ecology, The Environment and Conservation:

nachricht Northeast-Atlantic fish stocks: Recovery driven by improved management
04.02.2019 | Johann Heinrich von Thünen-Institut, Bundesforschungsinstitut für Ländliche Räume, Wald und Fischerei

nachricht New mathematical model can help save endangered species
14.01.2019 | University of Southern Denmark

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: Regensburg physicists watch electron transfer in a single molecule

For the first time, an international team of scientists based in Regensburg, Germany, has recorded the orbitals of single molecules in different charge states in a novel type of microscopy. The research findings are published under the title “Mapping orbital changes upon electron transfer with tunneling microscopy on insulators” in the prestigious journal “Nature”.

The building blocks of matter surrounding us are atoms and molecules. The properties of that matter, however, are often not set by these building blocks...

Im Focus: University of Konstanz gains new insights into the recent development of the human immune system

Scientists at the University of Konstanz identify fierce competition between the human immune system and bacterial pathogens

Cell biologists from the University of Konstanz shed light on a recent evolutionary process in the human immune system and publish their findings in the...

Im Focus: Transformation through Light

Laser physicists have taken snapshots of carbon molecules C₆₀ showing how they transform in intense infrared light

When carbon molecules C₆₀ are exposed to an intense infrared light, they change their ball-like structure to a more elongated version. This has now been...

Im Focus: Famous “sandpile model” shown to move like a traveling sand dune

Researchers at IST Austria find new property of important physical model. Results published in PNAS

The so-called Abelian sandpile model has been studied by scientists for more than 30 years to better understand a physical phenomenon called self-organized...

Im Focus: Cryo-force spectroscopy reveals the mechanical properties of DNA components

Physicists from the University of Basel have developed a new method to examine the elasticity and binding properties of DNA molecules on a surface at extremely low temperatures. With a combination of cryo-force spectroscopy and computer simulations, they were able to show that DNA molecules behave like a chain of small coil springs. The researchers reported their findings in Nature Communications.

DNA is not only a popular research topic because it contains the blueprint for life – it can also be used to produce tiny components for technical applications.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Global Legal Hackathon at HAW Hamburg

11.02.2019 | Event News

The world of quantum chemistry meets in Heidelberg

30.01.2019 | Event News

Our digital society in 2040

16.01.2019 | Event News

 
Latest News

Gravitational waves will settle cosmic conundrum

15.02.2019 | Physics and Astronomy

Spintronics by 'straintronics'

15.02.2019 | Physics and Astronomy

Platinum nanoparticles for selective treatment of liver cancer cells

15.02.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>