Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Endangered lemurs' genomes sequenced

27.03.2013
Three populations of aye-ayes on Madagascar studied

For the first time, the complete genomes of three populations of aye-ayes--a type of lemur--have been sequenced and analyzed. The results of the genome-sequence analyses are published this week in the journal Proceedings of the National Academy of Sciences (PNAS).

The research was led by George Perry, an anthropologist and biologist at Penn State University; Webb Miller, a biologist and computer scientist and engineer at Penn State; and Edward Louis of the Henry Doorly Zoo and Aquarium in Omaha, Neb., and Director of the Madagascar Biodiversity Partnership.

The aye-aye--a lemur that is found only on the island of Madagascar in the Indian Ocean--was recently re-classified as "Endangered" by the International Union for the Conservation of Nature.

"The biodiversity of Madagascar is like nowhere else on Earth, with all 88 described lemur species restricted to the island, but with less than 3 percent of its original forest remaining," said Simon Malcomber, program director in the National Science Foundation's (NSF) Division of Environmental Biology, which in part funded the research.

"It's essential to preserve as much of this unique diversity as possible," Malcomber said.

Added Perry, "The aye-aye is one of the world's most unusual and fascinating animals."

"Aye-ayes use continuously growing incisors to gnaw through the bark of dead trees. They have long, thin, flexible middle fingers to extract insect larvae, filling the ecological niche of a woodpecker.

"Aye-ayes are nocturnal, solitary and have very low population densities, making them difficult to study and sample in the wild."

Perry and other scientists are concerned about the long-term viability of aye-ayes as a species, given the loss and fragmentation of forest habitats in Madagascar.

"Aye-aye population densities are very low, and individual aye-ayes have huge home-range requirements," said Perry.

"As forest patches become smaller, there's a risk that there won't be sufficient numbers of aye-ayes in an area to maintain a population over multiple generations.

"We were looking to make use of new genomic-sequencing technologies to characterize patterns of genetic diversity among some of the surviving aye-aye populations, with an eye toward the prioritization of conservation efforts."

The researchers located aye-ayes and collected DNA samples from the animals in three regions of Madagascar: the northern, eastern and western regions.

To discover the extent of the genetic diversity in present-day aye-ayes, the scientists generated the complete genome sequences of 12 individual aye-ayes.

They then analyzed and compared the genomes of the three populations.

They found that, while Eastern and Western aye-ayes are somewhat genetically distinct, aye-ayes in the northern part of the island and those in the east show a more significant genetic distance, suggesting an extensive period during which interbreeding has not occurred between the populations in these regions.

"Our next step was to compare aye-aye genetic diversity to present-day human genetic diversity," said Miller.

"This analysis can help us gauge how long the aye-aye populations have been geographically separated and unable to interbreed."

To make the comparison, the team gathered 12 complete human DNA sequences--the same number as the individually generated aye-aye sequences--from publicly available databases for three distinct human populations: African agriculturalists, individuals of European descent, and Southeast Asian individuals.

Using Galaxy--an open-source, web-based computer platform designed at Penn State for data-intensive biomedical and genetic research--the scientists developed software to compare the two species' genetic distances.

The researchers found that present-day African and European human populations have a smaller amount of genetic distance than that between northern and eastern aye-aye populations, suggesting that the aye-aye populations were separated for a lengthy period of time by geographic barriers.

"We believe that northern aye-ayes have not been able to interbreed with other populations for some time," said Miller. "Although they are separated by a distance of only about 160 miles, high plateaus and major rivers may have made intermingling relatively infrequent."

The results suggest that the separation of the aye-aye populations stretches back longer than 2,300 years, when human settlers first arrived on Madagascar and started burning the aye-ayes' forest habitat and hunting lemurs.

"This work highlights an important region of aye-aye biodiversity in northern Madagascar, and this unique biodiversity is not preserved anywhere except in the wild," said Louis.

"There is tremendous historical loss of habitat in northern Madagascar that's continuing at an unsustainable rate today."

In future research, the scientists would like to sequence the genomes of other lemur species--more than 70 percent of which are considered endangered or critically endangered--as well as aye-ayes from the southern reaches of Madagascar.

In addition to Perry, Miller and Louis, scientists who contributed to the research include Stephan Schuster, Aakrosh Ratan, Oscar Bedoya-Reina and Richard Burhans of Penn State; Runhua Lei of the Henry Doorly Zoo and Aquarium and Steig Johnson of the University of Calgary in Alberta, Canada.

Funding for aye-aye sample collection was provided by Conservation International, the Primate Action Fund and the Margot Marsh Biodiversity Foundation, along with logistical support from the Ahmanson Foundation and the Theodore F. and Claire M. Hubbard Family Foundation.

Additional support came from the National Institutes of Health, the Pennsylvania Department of Health and the College of the Liberal Arts at Penn State University.

Media Contacts
Cheryl Dybas, NSF (703) 292-7734 cdybas@nsf.gov
Barbara Kennedy, Penn State (814) 863-4682 science@psu.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.

Cheryl Dybas | EurekAlert!
Further information:
http://www.nsf.gov
http://www.nsf.gov/news/news_summ.jsp?cntn_id=127343&org=NSF&from=news

More articles from Life Sciences:

nachricht Link Discovered between Immune System, Brain Structure and Memory
26.04.2017 | Universität Basel

nachricht Researchers develop eco-friendly, 4-in-1 catalyst
25.04.2017 | Brown University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Scientist invents way to trigger artificial photosynthesis to clean air

26.04.2017 | Materials Sciences

Ammonium nitrogen input increases the synthesis of anticarcinogenic compounds in broccoli

26.04.2017 | Agricultural and Forestry Science

SwRI-led team discovers lull in Mars' giant impact history

26.04.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>